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Design, synthesis, and investigation of a bio inspired CO₂ reduction catalyst
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i
DESIGN, SYNTHESIS, AND INVESTIGATION OF A BIO INSPIRED CO
2
REDUCTION CATALYST
by
Alon Chapovetsky
A Dissertation Presented to the
FACULTY OF THE USC GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(CHEMISTRY)
May 2019
ii
“You have to be able to accept failure to get better.”
Lebron Raymone James Sr.
iii
ACKNOWLEDGEMENTS
I would like to thank my advisor, Professor Smaranda C. Marinescu, for giving me the
freedom to pursue my own project with the only stipulation that my work must be great. It was a
tremendous fun to will new molecules into existence and study how they interact with carbon
dioxide. I also want to thank the rest of my committee, Professors Mark E. Thompson, Adam L.
Smith, Travis J. Williams, and Ralf M. Haiges. I learned a lot from all of you about doing science,
solving problems, and dealing with difficult people (me!). I appreciate all the mentorship and
patience.
To my coworkers, you are not my friends, you are family. I am glad none of you ever called
HR on me or I would have been in big trouble. We started out as the Fantastic Four (Courtney,
Andrew, Damir), crammed in a small office with no lab to work in, and we made do with what we
had. Those late nights we all put in during our first year are some of my fondest memories. Along
came Eric. Eric, you are a great…..Friend. Thank you for putting up with my nonsense as our fume
hoods were back-to-back. I am glad we have a lot of shared memes together, though hopefully
they will lighten up after we graduate. Nick and Ashley, I am glad to have worked with you. I
remember meeting you at that one recruiting event, and it’s been a good time ever since. We should
do more happy hours together. Next come my favorite roommate and favorite hombere. Keying,
your sharp and ruthless wit were always entertaining. Geo, thank you for introducing me to the
NYT crossword, or curse you for that, I am still not sure. Finally, Jeremy, thank you for taking
over the dry box, and for making us pickles. Keep representing our people at the Marinescu lab!
We all need to watch Infinity war 2 together.
The USC chemistry department has also played a major role in this degree, I would like to
acknowledge Professors Matthew R. Pratt, Richard L. Brutchey, and Brent C. Melot. It was great
having figures of authority who were willing to grab a beer and chat at a moment’s notice. Matt
Greaney and Sean Culver, thank you for helping me permanently destroy my liver. Anna Batt,
Narek Arabro, Nikki Peddowitz, Aaron Balana, Natalie Lamiri, Stuart Moon and Nick Bashian, I
had the best time going to KBBQ, American BBQ, or AYCE sushi with you fine folk on
Thursdays. Those dinners were anchors for when it seemed like everything was sinking away. I
was also fortunate to have fantastic friends outside of USC Chemistry. To the 6am GAINZ crew,
it was an honor lifting with you all. With you, I made both muscle gains and friendship gains,
iv
thank you for that. The lab crew, Shawndel, Kristian, Carlos, Oliver, and Kaylie. If anyone has
seen me at my lowest points (of which there were many), it was you, and with your help I managed
to get back up again. Also, thank you for the corporate discount.
To my dear friends outside of USC. Tamika, thank you for your constant guidance and advice. I’m
glad our friendship outlasted the 6th month mark and the pool party incident. I appreciate your
advice and guidance, even though I often don’t follow it. It was great to see how someone is killin’
the game post grad/med school. Hashtag goals. Also, thank you for introducing me to Rene-
Charles. Ameya Ganpule, you have been my best friend for a decade now. I feel like we are going
through similar processes in life. I appreciate the fact that I can call you at any time, and that you
always have fantastic advice. I wish you all the best as you further your education and career at U.
Michigan.
Finally, I’d like to thank my family, my parents and my grandparents. You sacrificed a
lot to get me to where I am, and I am forever grateful for that. You have taught me to always be
humble and work hard. The family motto of “вперед и вверх” will live and grow with me. My
grandparents: I am glad that you always made sure that I was full and had money. Your
unconditional love to me has been an important part of my success. My parents: your years of
imbuing culture and science into me have (hopefully) paid off. I know I’m only your second
favorite after your cat, but even so, thank you for being there for me.
v
TABLE OF CONTENTS
Acknowledgements ......................................................................................................................... iii
Table of Contents .............................................................................................................................v
List of Figures .............................................................................................................................. viii
List of Tables .................................................................................................................................. xi
Chapter 1. General Introduction ...................................................................................................1
1.1. General Introduction .....................................................................................................2
1.2. Hydrogenases as Models for Hydrogen (H2) Evolution Catalysts................................2
1.3. The Challenges of Reducing Carbon Dioxide (CO2) ...................................................4
1.4. Structure Reactivity Studies of CO-Dehydrogenase .....................................................5
1.5.Organometallic Complexes for CO2 Reduction .............................................................8
1.5.1. Cyclam Complexes ......................................................................................8
1.5.2. Bipyridine Complexes ...............................................................................10
1.5.3. Porphyrin Complexes ................................................................................13
1.6. Outline of the Work in this Thesis ..............................................................................17
1.7. References ...................................................................................................................19
Chapter 2. Hydrogen Bond Assisted Reduction of Carbon Dioxide (CO2) by a Cobalt
Aminopyridine Complex .................................................................................................26
2.1. Introduction .................................................................................................................27
2.2. Results and Discussion ...............................................................................................28
2.2.1 Synthesis and Characterization ............................................................................ 28
2.2.2 Electrochemical Studies ...................................................................................... 30
2.2.3 Controlled Potential Electrolysis ......................................................................... 34
2.2.4 Mechanistic Insights ............................................................................................ 35
2.3 Experimental Details and Additional Figures ....................................................................... 37
2.3.1 General ................................................................................................................. 37
2.3.2 Cyclic Voltammetry (CV) .................................................................................. 37
2.3.3 Controlled-Potential Electrolysis (CPE) ............................................................. 38
2.3.4 TOF Calculations from Cyclic Voltammetry ...................................................... 38
2.3.5 TOF CPE Calculations from Controlled Potential Electrolysis .............................. 39
2.3.6 Evans Method ...................................................................................................... 40
2.3.7 Synthesis .............................................................................................................. 41
2.3.8 Additional Figures and Data ................................................................................ 42
2.4 References ............................................................................................................................. 48
Chapter 3. Pendant Hydrogen-Bond Donors in Cobalt Catalysts Independently Enhance
Carbon Dioxide (CO2) Reduction ...................................................................................51
3.1. Introduction .................................................................................................................52
3.2. Results and Discussion ...............................................................................................54
3.2.1 Synthesis and Characterization ............................................................................ 54
3.2.2 Electrochemical Studies ....................................................................................... 55
3.2.3 Density Functional Theory (DFT) ...................................................................... 61
3.2.4 Mechanistic Insight .............................................................................................. 67
3.3 Conclusion ............................................................................................................................. 68
3.4 Experimental Details and Additional Figures ....................................................................... 70
3.4.1 General ................................................................................................................ 70
3.4.2 Cyclic Voltammetry (CV) .................................................................................. 70
vi
3.4.3 Controlled-Potential Electrolysis (CPE) ............................................................. 71
3.4.4 TOF Calculations from Cyclic Voltammetry ...................................................... 71
3.4.5 TOF CPE Calculations from Controlled Potential Electrolysis .............................. 71
3.4.6 Synthesis and Characterization ............................................................................ 72
3.4.7 Additional Electrochemical Data ......................................................................... 74
3.5 Computational Methods ......................................................................................................... 79
3.5.1 Density Functional Calculation Details ............................................................... 84
3.5.2 Computed Reduction Potential of 1
(II)
-6
(II)
......................................................... 84
3.5.3 Density Functional Calculations on the Binding of CO 2 ..................................... 86
3.5.4 Embedded Multireference Calculations on the Favorability of Hydrogen Bonding
in Complex 1
(II)
-CO 2 ........................................................................................... 87
3.5.5 Structure of the CO 2H Adduct ............................................................................. 90
3.5.6 Mechanism of the Second Protonation: Intra- versus Intermolecular Proton
Transfer ................................................................................................................ 91
3.5.7 Comparison of the Intra- versus Intermolecular Mechanism for the First
Protonation ........................................................................................................... 93
3.5.8 Calculation of Proton Free Energy ...................................................................... 93
3.5.9 Acidity of the Intermediates ................................................................................ 94
3.6 Analysis of the (E)ECEC Mechanism for the Second Protonation Step ............................... 94
3.6.1 Introduction .......................................................................................................... 94
3.6.2 Kinetics of the EECC Mechanism ..................................................................... 100
3.6.3 Additional Mechanisms Captured by the Rate Model ....................................... 100
3.7 References............................................................................................................................ 101
Chapter 4. Through-Space Charge Effects Modulate the Reduction Potentials of a Series of
Cobalt Aminopyridine Complexes ...............................................................................108
4.1. Introduction ...............................................................................................................109
4.2. Results and Discussion .............................................................................................111
4.2.1 Synthesis of Complexes ..................................................................................... 111
4.2.2 Electrochemical Characterization of 1’ and 5’ .................................................. 117
4.3 Conclusion........................................................................................................................... 121
4.4 Experimental Details and Additional Figures ..................................................................... 122
4.4.1 General ............................................................................................................... 122
4.4.2 Cyclic Voltammetry ........................................................................................... 122
4.4.3 TOF calculations from Cyclic Voltammetry ..................................................... 123
4.4.4 General Procedure for the Synthesis of 1’-5’ .................................................... 124
4.4.5 Independent Synthesis of 5-K ............................................................................ 124
4.4.6 Additional Figures ............................................................................................. 125
4.5 References ........................................................................................................................... 129
Chapter 5. Para Substitution in Cobalt Aminopyridine Catalysts Impacts the Proton Affinity
of a Bound CO2 Ligand ................................................................................................132
5.1. Introduction ...............................................................................................................133
5.2. Results and Discussion .............................................................................................135
5.2.1 Ligand Synthesis ................................................................................................ 135
5.2.2 Metalation and Physical Characterization ......................................................... 139
5.2.3 Electrochemical Characterization ...................................................................... 141
5.2.4 Controlled Potential Electrolysis ....................................................................... 145
5.2.5 Density Functional Theory Calculations of the First and Second Protonation .. 147
5.3 Conclusion ........................................................................................................................... 147
5.4 Experimental Details and Additional Figures ...................................................................... 149
vii
5.4.1 General .............................................................................................................. 149
5.4.2 Cyclic Voltammetry ........................................................................................... 149
5.4.3 Controlled Potential Electrolysis (CPE) ........................................................... 150
5.4.4 TOF Calculations from Cyclic Voltammetry .................................................... 150
5.4.5 Binding Constant Calculation from CVs ........................................................... 151
5.4.6 Density Functional Theory Calculation Details ................................................. 152
5.4.7 Synthesis of
CF3
L ................................................................................................ 153
5.4.8 Synthesis of
NMe2
L .............................................................................................. 157
5.4.9 Synthesis of
Mix
L ................................................................................................ 159
5.4.10 Synthesis of 2-4 ................................................................................................. 162
5.4.11 Additional Figures ............................................................................................. 163
5.5 References............................................................................................................................ 165
Bibliography ................................................................................................................................167
Appendix 3.1: Calculated coordinates for 1-6 ............................................................................178
Appendix 5.1: Calculated coordinates for 1-4 .............................................................................252
Appendix 5.2: NMR Spectra ........................................................................................................277
viii
LIST OF FIGURES
Figure 1.1 Structures of hydrogenases, mimics, and other catalysts ..............................................3
Figure 1.2 Selected CO2 reduction products and their standard redox potentials ...........................5
Figure 1.3 Product distribution for the Fischer-Tropsch reaction ...................................................5
Figure 1.4 Structure of the CODH active site .................................................................................6
Figure 1.5 Structure of the CODH active site after the addition of BuNCO and CN .....................7
Figure 1.6 Proposed catalytic mechanism for the reduction of CO2 to CO by CODH ...................8
Figure 1.7 Structure of the CO2 bound Cyclam Adduct .................................................................9
Figure 1.8 The Trans I and Trans III isomers of nickel cyclam ......................................................9
Figure 1.9 General Structure for rhenium and manganese bipyridine complexes .......................11
Figure 1.10 Schematic of the mechanisms for the reduction of CO2 to CO by bipyridine complexes
............................................................................................................................................12
Figure 1.11 Structures of manganese and rhenium bipyridine complexes with phenolic groups 13
Figure 1.12 Iron tetraphenyl porphyrin and its CO2 to CO reduction mechanism ......................14
Figure 1.13 Phenoxy functionalized porphyrins and its CO2 to CO reduction mechanism ..........15
Figure 1.14 Ionic moiety functionalized iron porphyrin ...............................................................16
Figure 2.1 Synthesis of 1 and 2 .....................................................................................................28
Figure 2.2 Solid state structures of 1 and 2 ...................................................................................29
Figure 2.3 Cyclic Voltammograms of 1 under various conditions ...............................................30
Figure 2.4 Control experiments for the electrochemical assignments of 1 ...................................31
Figure 2.5 Variable scan rate data for 1 ........................................................................................31
Figure 2.6 Plots of the observed rate of 1 under various conditions .............................................32
Figure 2.7 Cyclic voltammetry characterization of 2 ...................................................................33
Figure 2.8 Controlled potential electrolysis data for 1 and 2 .......................................................34
Figure 2.9 Proposed catalytic cycle for 1 ......................................................................................35
Figure 2.10 solid state structure of 1
-
............................................................................................42
Figure 2.11 Titration of 1
-
with TFE .............................................................................................42
Figure 2.12 Cyclic voltammogram of 1 in 4:1 MeCN:DMF under N2 atmosphere .....................43
Figure 2.13 Cyclic voltammogram of 1 in 4:1 MeCN:DMF under CO2 atmosphere ...................43
Figure 2.14 Cyclic voltammogram of 1 in DMSO .......................................................................44
Figure 2.15 Control experiments of 1 ..........................................................................................44
Figure 2.16 Titration of 1 with CO2 with no external acid present ...............................................45
Figure 2.17 Titration of 1 with CO2 with an external acid present ...............................................45
Figure 2.18 Catalyst loading experiment of 1 ...............................................................................46
Figure 2.19 Results for the titration of 1 with TFE and TFE-d4 ...................................................46
Figure 2.20 Log-Log plots of the observed rate of 1 under various conditions ............................47
Figure 2.21 Controls for the controlled potential electrolysis of 1 and 2 .....................................47
Figure 3.1 Syntheses and schematic of complexes 1-6 .................................................................54
Figure 3.2 Solid state structures of 2-5 .........................................................................................57
ix
Figure 3.3 Variable scan rate data for 2-5 .....................................................................................58
Figure 3.4 Cyclic voltammograms of 2-5 under N2 and CO2 .......................................................59
Figure 3.5 Titration plots for complexes 2-5 ................................................................................59
Figure 3.6 Plot of the observed rates of 1-5 versus [TFE] and versus the number of the NH groups
............................................................................................................................................60
Figure 3.7 Plot of the observed rate constants for 3-5 versus [TFE] at different scan rates .........61
Figure 3.8 Geometries and energies for intramolecular H-bonds between CO2 and the ligand ...63
Figure 3.9 Experimental rate constants versus CO2 binding energies ..........................................63
Figure 3.10 Plots comparing the two protonation energies for CO2 and solvent effects ..............65
Figure 3.11 Schematic comparing Inter- and Intramolecular proton transfer for CO2 .................66
Figure 3.12 Proposed EECC mechanism for 1-6 ..........................................................................67
Figure 3.13 Plot of current densities and the log of the rates versus [TFE] for 1-6......................79
Figure 3.14 Controlled potential electrolysis data for 1-6 ............................................................79
Figure 3.15 Controls for the controlled potential electrolysis of 2 ...............................................80
Figure 3.16 Controls for the controlled potential electrolysis of 3 ...............................................80
Figure 3.17 Controls for the controlled potential electrolysis of 4 ...............................................81
Figure 3.18 Controls for the controlled potential electrolysis of 5 ...............................................81
Figure 3.19 Titration plots of 3 at 2000 mV/s...............................................................................82
Figure 3.20 Titration plots of 4 at 2000 mV/s...............................................................................83
Figure 3.21 Titration plots of 5 at 2000 mV/s...............................................................................83
Figure 3.22 Top and side views of the optimized geometries of 1 ...............................................86
Figure 3.23 Comparison of the experimental and calculated Co
2/1
potentials ..............................87
Figure 3.24 Geometries and energies for the interaction between 1 and CO2H ..........................92
Figure 3.25 Structure of the hydrogen bonding network between 1, CO2H and H2O ..................92
Figure 3.26 Proposed (E)ECEC mechanism for 1-6 .....................................................................95
Figure 3.27 Time series for the concentrations of CO and various intermediates .......................98
Figure 3.28 Numerically computed rate as a function of [CO2] ...................................................99
Figure 3.29 Numerically computed rate as a function of [TFE] ...................................................99
Figure 4.1 General scheme describing 1-6 ..................................................................................110
Figure 4.2 Overlay of the solid-state structures of 1 and 1’ ................................................................................. 112
Figure 4.3 Schematic depicting the deprotonations of 1-4 to make 1’-4’ ...................................113
Figure 4.4 Overlays of the solid-state structures of 2-4 and 2’-4’ ..............................................114
Figure 4.5 Schematic and solid-state structures of 5’ .................................................................115
Figure 4.6 Variable temperature
1
H NMR spectrum of 5’ ..........................................................116
Figure 4.7 Schematic and solid-state structure of 5-K ................................................................116
Figure 4.8 Cyclic voltammogram of 1’ under N2 .......................................................................117
Figure 4.9 Acid titration of 1’ under CO2 and kinetic data .........................................................118
Figure 4.10 Cyclic voltammograms of 1’ with 1 and with TFE .................................................119
Figure 4.11 Cyclic voltammogram of 5’ under N2 and CO2 .......................................................120
Figure 4.12 Comparison of the cyclic voltammograms of 5 and 5’ under N2 and CO2 .............120
x
Figure 4.13 Acid titration of 5’ under CO2 and kinetic data .......................................................120
Figure 4.14
1
H NMR spectra of 1 before and after NaH addition ..............................................125
Figure 4.15
1
H NMR spectra of 2 before and after NaH addition ..............................................125
Figure 4.16
1
H NMR spectra of 3 before and after NaH addition .............................................126
Figure 4.17
1
H NMR spectra of 4 before and after NaH addition ..............................................126
Figure 4.18
1
H NMR spectra of 5 before and after NaH addition ..............................................127
Figure 4.19 Solid-state structure of 2 ..........................................................................................127
Figure 4.20 Solid-state structure of 3 ..........................................................................................127
Figure 4.21 Solid-state structure of 4 ..........................................................................................128
Figure 5.1 General scheme describing the para substitutions .....................................................135
Figure 5.2 Synthetic scheme for the preparation of
CF3
L ............................................................137
Figure 5.3 Synthetic scheme for the preparation of
NMe2
L ..........................................................138
Figure 5.4 Synthetic scheme for the preparation of
Mix
L ............................................................139
Figure 5.5 Overlay of the solid-state structures of 2 and 2’ ........................................................140
Figure 5.6 Overlay of the solid-state structures of 4 and 4’ ........................................................140
Figure 5.7 Cyclic voltammograms of 1-4 under N2 ....................................................................142
Figure 5.8 Cyclic voltammograms of 1-4 under N2 and CO2 .....................................................143
Figure 5.9 Cyclic voltammograms of the titrations of 2-4 under CO2 with TFE .......................144
Figure 5.10 Plot of the rates of 1-4 versus [TFE] and the corresponding Log-Log plots ..........144
Figure 5.11 Controlled potential electrolysis data for 2-4 ..........................................................145
Figure 5.12 Variable scan rate data for 2-4 .................................................................................163
Figure 5.13 Controls for the controlled potential electrolysis of 2-4 ..........................................164
xi
LIST OF TABLES
Table 3.1 Parameters for complexes 1-6 .......................................................................................55
Table 3.2 Summary of CPE data for complexes 1-6 .....................................................................82
Table 3.3 CO2 binding properties for X
(I)
-CO2 where X = 1-6 .....................................................88
Table 3.4 Localized molecular orbital numbers for each geometry considered ..........................90
Table 3.5 Geometric and charge properties for X
(II)
-CO2H where X = 1-6 ..................................91
Table 3.6 Comparison of the intermediates for Intra- and Intermolecular protonation for the first
and second protonation steps .............................................................................................93
Table 3.7 pKa for intermediates of the catalytic cycle ..................................................................94
Table 5.1 Structural parameters for 1-4 ......................................................................................141
Table 5.2 Electrochemical parameters for 1-4 ............................................................................142
Table 5.3 Calculated first and second protonation energies for 1-4 ............................................147
1
CHAPTER 1
General Introduction
2
1.1 General Introduction
Global reliance on fossil fuels has given rise to multiple energy-related problems to be
faced over the next 50 years
1-3
. Increased worldwide dependence on fossil fuels is gradually
leading to depleting oil reserves and subsequently higher financial and political costs for its
obtainment and distribution. At the same time, the environmental impact of carbon dioxide (CO2),
an emission product from the combustion of fossil fuels has started to take effect with global
climate change and ocean acidification
2,4
. Further use and reliance on fossil fuels is expected to
exasperate the above issues to a point of no return. The transformation of our current fossil fuel
dominated system to one that is CO2-neutral will require switching to non-fossil energy sources
such as solar, wind, nuclear, and geothermal
5-7
. The development of methods to harness and
transform the energy produced by these new sources into forms that can be stored, transported,
and used on demand is a major scientific and engineering problem.
Most of all fossil fuels ultimately start as CO2. The process that drives the carbon fixation
of CO2 into these fuels is photosynthesis, the biological method through which plants and
organisms convert carbon dioxide, sunlight, and water into reduced organic materials. An
estimated 390×10
9
tons of carbon dioxide are fixed biologically annually
8
, and the value added of
the fixation products is larger by a factor of two
9
. Living organisms have evolved over the course
of billions of years to extract energy and nutrients from their environment, resulting in a diverse
set of enzymes with different pathways for making and breaking C-H, C-C, and C-O bonds from
readily available materials. These pathways involve the storage and utilization of energy from
chemical bonds in a controlled, selective manner. Other than CO2 reduction, enzymatic processes
have been shown to possess pathways that can use and generate hydrogen (H2), ammonia (NH3),
and water (H2O) from acidic protons, dinitrogen, and dioxygen. Thus, biological systems have
developed their own H2, CO2, NH3, etc. economies and can be used as model systems for the
development of effective catalysts.
1.2 Hydrogenases as models for H2 evolution catalysts
Hydrogenases are a class of enzymes that can catalyze the production of H 2 from two
protons and two electrons and the reverse reaction, H2 oxidation
10-13
. Structural studies of these
3
enzymes reveal an active site consisting of a bimetallic motif (two irons for [FeFe] hydrogenase
and an iron and a nickel atom for the [NiFe] hydrogenase) ligated by carbonyl (CO), Cyanide
(CN), and thiolate ligands (Figure 1.1, structures 1 and 2)
10,14,15
. While thiolates are ubiquitous in
metallo-enzymes, CO and CN ligands are unusual. These ligands bind to low valent metals and
form low spin complexes which are known to interact with hydrogen to form hydride
intermediates
11,12,16
. Understanding the active site ligand field effects has been useful for synthetic
chemists when designing organometallic catalysts and trying to produce similar coordination in
artificial systems. A broad range of low spin organometallic complexes bearing CO, CN,
phosphine, and other strong field ligands have been synthesized and investigated with respect to
their ability to evolve H2
2,17,18
. While these complexes exhibit activity for H2 production, it is
generally sluggish and at very negative potentials when compared to those of the enzymes.
However, these results serve as a useful starting point for structure/activity investigations.
Figure 1.1. Structures of hydrogenases (1 and 2), selected hydrogenase mimics (3-5), and
hydrogenase inspired complexes (6 and 7)
A unique structural feature of [FeFe] hydrogenase is the presence of a 2-azapropane-1,3-
dithiolate ligand bridging the two iron atoms
19,20
. The position of the nitrogen atom has been
thought to assist in H2 cleavage and proton delivery by acting as a base, while the distal iron acts
as a lewis acid or a hydride acceptor. Due to the ability of the enzyme to reduce protons or oxidize
4
H2 reversibly, the hydride acceptor ability of the iron and the proton acceptor ability of the pedant
nitrogen must be matched to afford a net zero energy for H2 addition or release. The pendant amine
is also thought to shuttle protons from the enzyme to the active site as well, thus, giving rise to a
proton conduction channel within the enzyme
10,21
. These structural features have led to a series of
synthetic models that support these observations. Complexes 3-5 in Figure 1.1 showcase various
man-made mimics in which a diiron fragment is stabilized by a 1,3-dithiopropane ligand
22-25
.
Studies in which the identity of the masthead atom has been varied between carbon, oxygen, and
nitrogen support the hypothesis that the heteroatom is crucial for H2 manipulation. These findings
have inspired a gamut of H2 evolution and oxidation catalysts with secondary sphere elements,
including and not limited to other [FeFe] and [NiFe] hydrogenase mimics, nickel, cobalt, and iron
complexes bearing diphosphine ligands, and iron and nickel porphyrin complexes with hangman
functionalities (Figure 1.1, Complexes 6-7)
2,21-29
.
The outcomes described above, where the understanding of the relationship between the
active site and its reactivity is derived and refined, are a result of a synergistic interaction between
scientists from a broad range of disciplines, including but not limited to biologists, spectroscopists
and synthetic chemists. In recent years, a similar methodology has been implemented for the
elucidation and development of design principles for new catalysts for CO2 reduction.
1.3 The challenges of reducing CO2
Carbon dioxide is a linear triatomic molecule consisting of a single carbon double bond to
two oxygen atoms
30
. The high bond order, coupled with the overall closed electronic structure
make CO2 kinetically and thermodynamically stable. In most examples, the first step in CO2
reduction involves the addition of a single electron to form the bent radical anion. This requires
both a geometric reorganization and an orbital rehybridization within the molecule, along with the
lowering of the bond order between the carbon and oxygen atoms. Consequently, this step bears a
large thermodynamic cost (Figure 1.2)
31
. While a multielectron, multiproton reduction is
thermodynamically more favorable (Figure 1.2), the concerted delivery of multiple equivalents of
protons and electrons is kinetically challenging
32
.
5
Figure 1.2. Selected CO2 reduction processes and the corresponding standard redox potentials E
o’
in aqueous solutions
Depending on the quantity of protons and electrons, CO2 can be reduced to a broad range
of products. The most common are formate (HCO2
-
) and carbon monoxide (CO)
33
. While formate
and formic acid have found use as reagents and fuels, carbon monoxide has an even broader range
of uses and applications. Through the Fischer-Tropsch process, carbon monoxide and hydrogen
gas can be converted to a product spanning methane to long chain hydrocarbons, making CO an
industrially significant commodity (Figure 1.3)
34,35
.
Figure 1.3. Schematic showing the product distribution from Fischer-Tropsch reactions with
various ratios of CO and H2
1.4 Structure reactivity studies of Co Dehydrogenase (CODH)
While manmade CO2-to-CO reduction is not facile, some enzymes can perform the reaction
reversibly, at high turnovers, and under ambient conditions. CO-Dehydrogenase (CODH) is an
enzyme that can catalyze reduction of CO2 to CO reversibly
2,36
. Structural studies of the enzyme
and its active site reveal a Fe3S4 cluster coordinated to Ni and Fe metal centers (Figure 1.4)
3637
.
6
The rigidity of the cluster positions the two metal centers in close proximity. In its resting state,
the Ni
II
center is stabilized by three sulfur ligands giving rise to an unusual T-shaped environment,
suggesting the presence of a hydride ligand
38,39
. The Fe atom is coordinated by two amino acid
residues (Histidine H261, and Cystine C295), a µ3-sulfido ligand and another light atom, potentially
water/hydroxide. The proximity of the two metal atoms and the geometry around them suggest
that the two operate in a synergistic fashion during catalysis
39
.
Figure 1.4. Structure of the CODH active site
Structural studies of the active site after being chemically reduced and treated with
bicarbonate reveal a three-atom bridge between the Ni and Fe atoms that was hypothesized to be
CO2. Reactions of CODH with n-Butyl isocyanate (buNCO), a CO2 analogue, and subsequent
structural characterization have shown that Ni is bound to the isocyanate ligand via the carbon
atom and is not interacting with the Fe atom ( Figure 1.5, left)
37,40
. Histidine93, and the water
molecule bound to the Fe atom were found to stabilize the isocyanate oxygen through hydrogen
bounding interactions. It is hypothesized that a bound CO2 ligand would coordinate analogously
41-
45
. Reaction between the active site and cyanide, a CO analogue, and subsequent structural
characterization reveal a binding interaction between the Ni atom and the cyanide ligand through
the carbon atom and hydrogen bond stabilization between a distal Lysine (K563) and the cyanide
nitrogen (Figure 1.5, right)
46-48
. In the above experiment, the NiCN moiety is a structural and
electronic analogue to the NiCO center before the release of CO and regeneration of the active
site
49,50
.
7
Figure 1.5. Structure of the CODH active site after the addition of buNCO (left) and cyanide
(right)
Based on the above observations and other studies, a mechanism for the reduction of CO 2
by CODH can be proposed. In the first step the active site is reduced by two electrons in the
presence of CO2 (Figure 1.6, 1 to 2). In the resultant intermediate, CO2 is bound to the Ni atom
through the carbon and is further stabilized via hydrogen bond interactions to a distal H93 as seen
in the carbonate and BuNCO examples. In the next step, the Fe loses the water/hydroxide and
binds to one of the CO2 oxygen atoms to produce a bimetallic biding motif (Figure 1.6, 2 to 3).
This interaction is further stabilized by a hydrogen bond from a distal Lysine (K563) to the Fe bound
oxygen atom. Subsequently, the C-O bond is cleaved, and water is removed to generate a NiCO
species as been previously shown by the cyanide analogue (Figure 1.6, 3 to 4). In the last step, CO
is readily released, and a new water molecule is added to regenerate the catalyst and complete the
cycle (Figure 1.6, 4 to 1). These results suggest that an effective CO2 reduction catalyst must have
a few key structural features. Namely, the catalytic active site must contain both a metal with an
open coordination site for CO2 binding and outer sphere hydrogen bond donors to stabilize the
reactive bound intermediates and facilitate proton transfer to CO2
37
.
8
Figure 1.6. Proposed catalytic mechanism for the reduction of CO2 to CO by CODH
1.5 Organometallic complexes for CO2 reduction
1.5.1 Cyclam complexes
The design and synthesis of organometallic catalysts for CO2 reduction has been evolving
for many decades
2
. One of the most prototypical and well-studied organometallic systems for CO2
reduction is a family of nickel and cobalt tetraazacycles (cyclam, Figure 1.7)
51-53
. The first
successful use of Ni Cyclam catalysts for CO2 reduction was reported in the early 1980’s by
Eisenberg et al
51
. The initial report inspired many studies and further investigation into the
structure and reactivity of the complexes and how those were related to the CO2 reduction
mechanism. These studies are still ongoing
3,4,51-57
. A distinctive feature of the nickel and cobalt
cyclam systems is the involvement of the low valent congeners of the above metals, serving as
strong one electron reductants
51
. Reaction with CO2 usually begin with a nucleophilic attack of the
reduced metal ion on the carbon atom of CO2. The experimental CO2 binding constants span from
less than one to 10
8
M
-1
and anywhere in between, indicating that the binding affinity to CO 2 can
be tuned by ligand and metal modification
58,59
. Another unique and bio-relevant feature of the
metal cyclam species is intramolecular hydrogen bonding to the ligand NH protons. This
9
interaction has been structurally characterized for a Co-CO2 adduct spectroscopically and
crystallographically (Figure 1.7)
55
.
Figure 1.7. Structure of the CO2 bound cobalt cyclam specie
In some cases, CO2 is bound to two cobalt cyclam moieties through the carbon atom and
one of the oxygen atoms, reminiscent of the bimetallic interaction observed in CODH
58
.
Electrochemical studies have also shown the importance of amines in stabilizing CO2 transfer and
facilitating proton transfer. A series of cobalt cyclam complexes with varying methyl substitutions
on the amines have been synthesized and investigated regarding their electrochemical CO 2
reduction ability. It was shown that increased methylation contributed to a decrease in activity
55,60
.
The rationale behind this behavior was that the steric profile of the methyl groups, along with the
lack of hydrogen bonding interactions is inhibitive for CO2 reduction. For the fully protonated
cyclam specie, the most common isomers in solution are the trans I where all four hydrogens are
on the same face of the complex and trans III in which each pair of hydrogens point toward
opposite directions. Density Functional Theory (DFT) studies have shown that the trans I has a
more favorable binding affinity towards CO2 than that of the trans III (Figure 1.8)
55
. The difference
is affinities was explained by the fact that in the trans I isomer CO2 experiences two hydrogen
bonding interactions while in the trans III it experiences only one.
Figure 1.8. The Trans I and Trans III isomers of nickel cyclam
10
Cyclam species have shown a propensity for intermolecular bonding interactions in
addition to intramolecular hydrogen bonding. In non-protic solvents such as tetrahydrofuran
(THF), the identity of the electrolyte ion is important
58,61
. The binding constant has been shown to
range over two orders of magnitudes depending on the identity of the supporting electrolyte,
indicating that electrostatic interactions between the active specie and the electrolyte salt are
imperative for M-CO2 adduct formation. Finally, the solvent choice is also critical for reactivity.
While electrolysis in water (pH 4 to 5) produces CO at high turnovers and selectivity, the same
experiment, when done in aprotic solvents gives rise to formic acid in up to 75% faradaic
efficiency
59,62
. The above results suggest that in the case of metal cyclam species, catalysis depends
not only on the first coordination sphere (metal center and surrounding ligands) but also the second
coordination sphere (ligand NH groups) and the overall environment (solvent and electrolyte).
This is analogous to CODH in which all three elements have a profound effect on catalysis.
However, in the case of cyclam, alteration of the second coordination sphere (methylation of NH
groups) has a direct impact on the first coordination sphere (alteration of the electronic character
of the nitrogen atoms). Hence, a clear relationship between the activity of the complex and the
secondary sphere contributions cannot be elucidated.
1.5.2 Bipyridine complexes
Manganese and rhenium bipyridine complexes are another family of well-studied CO2
electrocatalysts (Figure 1.9)
63,64
. Early reports by Lehn and coworkers have shown that a rhenium
tris carbonyl bipyridine complex fac-[Re(bpy)(CO)3Br] (since all the Mn and Re complexs
discussed are fac-, this prefix will be dropped from now on) can reduce CO2-to-CO efficiently and
selectively
2
. Due to the shift toward more sustainable and abundant elements for use as catalysts,
focus shifted toward manganese bipyridine complexes. Even though manganese is several orders
of magnitude more abundant than rhenium, the first report citing the activity of manganese
bipyridine complexes for CO2 reduction came out in 2011
65
. Substitution of the rhenium metal
center with manganese gave rise to a positive shift in potential (approximately 0.4 V) along with
impressive stability and selectivity toward CO2
66,67
. However, it was shown that both complexes
studied, [Mn(bpy)(CO)3Br] (where bpy =4,4’-dihydro-bipyridine and 4,4’-dimethyl-bipyridine),
required the addition of a proton source, as opposed to the rhenium congeners that could abstract
a proton from solvent and electrolyte molecules in solution
68
.
11
Figure 1.9. General structure of metal bipyridine complexes relevant to catalyzing the CO2-to-CO
reduction
A series of synthetic, spectroscopic, and theoretical studies have produced a large amount
of evidence pertaining to the mechanism through which catalysis occurs (figure 1.10, Reduction
first pathway)
69-72
. Under an inert atmosphere (N2 or Ar), [Mn(bpy)(CO)3Br] exhibits two one
electron reduction events at -1.6 V vs. Fc
+
/Fc ferrocene and -1.9 V vs. Fc
+
/Fc. The first reduction
is metal based, giving rise to a loss of halogen and formation of a dimer. The second reduction
cleaves the dimer to yield a five-coordinate monomer. X-ray Absorption spectroscopy has shown
that the electron from the second reduction is stored on the ligand, as opposed to the metal
73,74
.
This is in stark contrast to the metal cyclam examples, in which all the reductions are metal based.
The doubly reduced five-coordinate specie reacts with CO2 to form a new moiety in which the
bent CO2 radical anion is bound to the metal center through the carbon atom. In the presence of
acid, the bound CO2 is protonated to form a hydroxycarbonyl ligand. At negative potentials, this
specie is reduced and protonated again to release water, CO, and regenerate the singly reduced
catalyst
75
. The substitution of the 6,6’ positions with bulky mesityl groups has been shown to
inhibit dimerization and shift the second reduction potential positively by -1.7 V vs. Fc
+
/Fc
71
.
Given that the second reduction in the metal bipyridine mechanism occurs on the ligand, many
attempts have been made to alter its reactivity by introducing electron donating and withdrawing
groups into the ligand backbone. In a recent study, a series of six rhenium bipyridine complexes
with various substitutions (OCH3, tBu, CH3, H, CF3, and CN) in the 4,4’ positions have been
synthesized and characterized electrochemically
76
. It was shown that the incorporation of mildly
electron donating substituents, such as tBu and CH3 was shown to increase the activity and
overpotential of the catalyst with respect to the parent complexes. Strongly electron donating
(OCH3) and strongly electron withdrawing (CN, CF3) substituents have shown to either inhibit
12
catalysis by destabilizing the ligand or by permitting other parasitic reactions to occur
76
. The
relationship between the electronic environment around the metal center in the case of the
manganese and rhenium bipyridine complexes exemplifies the importance of the first coordination
environment in a biological environment like the CODH. It has been proposed that part of the
reason that CODH and other enzymes can operate near the thermodynamic potential is due to the
complex coordination environment around that can facilitate a well-timed electron transfer to the
bound substrate.
Figure 1.10. Mechanistic schemes showcasing the reduction first (green) and protonation first
(red) pathways for the reduction of CO2 to CO by manganese bipyridine complexes.
The activity of the manganese bipyridine system has been successfully improved through
the incorporation of hydrogen bond donors and pendant proton relays. Replacement of the bulky
mesityl groups with 2,6-dimethoxyphenyl units was shown to be a promising strategy for catalyst
improvement
77,78
. The dimehoxyphenyl units impart a larger electron density onto the bipyridine
ligand compared to the mesityl groups and have hydrogen bond capable ethers in close proximity
to the metal. In the proposed mechanism for the 2,6-dimethoxyphenyl substituted manganese
bipyridine complex, a two-electron reduction forms the active species. In the presence of CO2 and
protons, this species reacts to form the hydroxycarbonyl bound metal complex (figure 1.10,
Protonation first pathway). Due to the stabilization of the hydroxycarbonyl moiety by a hydrogen
bond to the ligand, the barrier for the second reduction is significantly lower, thus, opening the
13
access to a protonation first pathway that is 0.55 V more positive with respect to the reduction first
pathway
78
. These results are supported by spectroscopic and theoretical studies. Manganese
bipyridine ligands with phenoxy groups have also been synthesized and investigated with respect
to their reactivity toward CO2 (Figure 1.11).
Figure 1.11. Structures of [Mn(hp-bpy)(CO)3Br] and [Mn(pd-bpy)(CO)3Br]
While lacking some of the bulk afforded by the 2,6-dimethoxyphenyl units, the steric and
electronic profile of the mono and di- phenoxy groups was also sufficient for inhibiting
dimerization. Both complexes exhibited a lower overpotential with respect to the parent
complexes
77,79
. The presence of a proton donor near the metal center was shown to engage in a
hydrogen bonding interaction with the bound CO2 ligand, enable proton transfer, and thus, enable
the rate determining step. Controlled potential electrolysis (CPE) experiments and subsequent
analysis showed the presence of formate, whose formation was promoted by small amounts of
metal hydride species in solution
77,79
. The incorporation of hydrogen bond donors into rhenium
and manganese bipyridine complexes was shown to have an impact on the turnover number,
overpotential, and even selectivity of the catalyst. However, the coupling between the first and
second coordination spheres prohibits the elucidation of the role of that pendant proton donors
play in catalysis.
1.5.3 Porphyrin Complexes
Finally, the last prototypical system of CO2 reduction catalysts to be discussed in this work
is the iron porphyrin family of complexes
80-84
. First reported in 1980, the activity of the tetraphenyl
iron chloride [TPPFe] was investigated in the absence of proton donors (Figure 1.12). Under a CO2
atmosphere, CPE experiments of [TPPFe] gave rise to formation of CO, along with a rapid
deactivation of the catalyst via carboxylation and hydrogenation of the ligand. The catalyst
stability and activity were dramatically enhanced upon the addition of Lewis acids as supporting
14
electrolytes. A series of mono- and divalent ions were tested, and it was found that the activity had
the order Mg
2+
≈ Ca
2+
> Ba
2+
> Li
+
> Na
+
. CPE studies and subsequent analysis showed that the
main products of the electrolysis were CO and carbonate (CO3
2-
), with formate as a side product
(10-30% faradic efficiency).
Mechanistic investigations produced a catalytic cycle in which the complex is reduced by
three electrons to make an Fe
0
complex. This reactive specie attacks CO2 to form an intermediate
adduct. In the presence of a second equivalent of CO2, the adduct disproportionates to produce
carbon monoxide and carbonate
83,84
. The rationale behind the enhancement in stability with the
addition of a Lewis acid has to do with the formation of an ion pair between the negatively charged
oxygen atoms on the bound CO2 ligand and the positive charge of the Lewis acid (Figure 1.12, A)
83
.
Figure 1.12. Schematic of the [FeTPP] complex and the CO2 reduction mechanism in the presence
of (A) lewis acids and (B) protons
This interaction is thought to weaken the C-O bonds of CO2 and thus, accelerate catalysis.
It is important to note that the addition of the Lewis acid must be stoichiometric to accommodate
for the formation of the carbonate salt. Post C-O bond breaking, the resultant Fe
II
carbonyl is
reduced electrochemically or homogeneously by a second Fe
0
and is decarbonylated to regenerate
the catalyst
85,86
. While these results were very promising, the scope of catalysis is limited since
during electrolysis MgCO3 precipitates onto the electrode, thus inhibiting prolonged electrolysis
82
.
15
Iron porphyrin catalyzed reduction of CO2 in the presence of protons has also been
investigated and successfully optimized. It was found that addition of a bronstead acid such as 1-
propanol, 2-pyrrolidinone, or 2,2,2-trifluoroethanol leads to a significant increase in the catalytic
wave, proportional to acidity of the proton source
80,81
. The proposed catalytic cycle for this system
is analogous with the one proposed for catalysis in the presence of a Lewis acid (Figure 1.12, B).
The Fe
II
-CO2 adduct is stabilized by hydrogen bonding interactions to two acid molecules
(consistent with a second order dependence on acid). The protonation and C-O bond cleavage was
examined more closely by varying the acid type, concentration, and even measuring a kinetic
isotope effect for different acids. Based on the data collected in those experiments, a proton-
coupled electron transfer bond cleavage was proposed as the rate-determining step for this
reaction
81
. Catalyst performance was further improved by installing phenolic and ethereal groups
into the ortho and ortho’ positions of the phenyl substituents in the porphyrin framework (Figure
1.13)
87
. While both species saw a catalyst enhancement, phenoxy substituted complex has shown
a 9-order magnitude performance increase over the ethoxy analogue.
Figure 1.13. Structure of the phenoxy and methoxy substituted porphyrin complexes (top) and
their proposed mechanism for CO2 reduction.
Mechanistic investigations have shown that the incorporation of hydrogen bond donors
alters the mechanism of catalysis (Figure 1.13). Following a reduction to make a Fe(0), CO2 binds
to the metal and is stabilized by hydrogen bonds to the pendant phenol groups. This interaction is
16
so stabilizing that it requires a further reduction to proceed. This second reduction is more difficult
than the first, in contrast to the unsubstituted porphyrin complex
87-89
. Furthermore, the
reprotonation of the catalyst was proposed to occur in a concerted fashion with the electron transfer
step
90
. Overall, the phenolic groups on the TPP ligand had a role in both stabilizing the reactive
Fe(II)-CO2 adduct and in enhancing the local proton concentration.
The influence of electronic substituent effects on the performance of iron porphyrin
complexes for CO2 reduction has also been investigated through the synthesis of a series of
porphyrin complexes with one, two, three, and four perfluorphenyl rings. Two trends were
observed regarding catalyst performance
91
. First, the overpotential was shown to decrease with
increasing perfluorination. The significant decrease in the overpotential corresponds to the lower
electron density on the metal center brought upon by increasing perflurophenyl groups
91
. Second,
the decrease in electron density on the metal center also lead to a lower catalytic rate constant. By
decreasing the nucleophilicty of the metal center, the catalyst’s ability to attack and bind CO 2
decreases, as reflected in the rate. Additional improvements were brought upon the FeTPP system
by the incorporation of ionic moieties into the ligand scaffold
91
. The tradeoff between catalytic
activity and overpotential is an example of a scaling relationship
92
. The introduction of four
cationic trimethylammonium groups into the para positions of the porphyrin phenyls gave rise to
a water-soluble catalyst capable of reducing CO2 at high rates and low overpotential (Figure
1.14)
93,94
.
Figure 1.14. Structure of the iron tetraphenylporphyrin complex with ionic moieties
17
The deviation of this catalyst from the scaling relationship indicates that the influence of
the cations is governed by different phenomena. An analogous complex with the
trimehylammonium groups in the ortho positions was shown to perform at faster rates at an even
smaller overpotential as compared to the para substituted derivative. While this mechanism is
poorly understood, it is suggested that the bound cations stabilize the Fe
(II)
-CO2 adduct through
columbic interactions. This is the most efficient homogenous catalyst for CO2-to-CO conversion
to date
93
.
1.6 Outline of the work ahead
While a lot of work has gone into the development of molecular catalysts, there are still
issues to be overcome. The complicated scaling relationships between the overpotential, turnover
number, faradic efficiency, and other parameters make the design and optimization of new
catalysts a difficult task. In this thesis, we look to expand the scope of knowledge pertaining to
the relationship between the first and second coordination spheres of organometallic complexes
and its turnover frequency, overpotential, and selectivity by synthesizing a new ligand system in
which the first and second coordination spheres are not only tunable, but also completely
decoupled.
In chapter two we will present a novel cobalt aminopyridine complex bearing pendant
amines that is capable of reducing CO2-to-CO at high turnovers and selectivities. Alkylation of all
the amines inhibits catalysis, giving rise to an 850-fold decrease in activity. Titration experiments
of various substrates (cobalt complex, protons, CO2) under various conditions along with isotopic
studies suggest that catalysis proceeds though a EECC (where E denotes an electrochemical step
and C denotes a chemical step) mechanism. Upon a two-electron reduction (EE), the cobalt metal
center attacks the central CO2 carbon to make a Co
I
-CO2 adduct (C). This adduct undergoes two
protonations, one of which is rate determining (C), to produce CO and water and regenerate the
catalyst.
In chapter three, we will characterize a series of cobalt aminopyridine complexes with
varying configurations and substitution patterns of hydrogen bond donors and methyl groups in
18
the secondary coordination sphere. Electrochemical investigations show that while all these
complexes are competent and selective CO2-to-CO reduction catalysts, their activities vary
proportionally to the number of pendant amines around the metal center. The activity of the
catalysts did not scale with the overpotential, indicating that any reactivity is due to the second
sphere, exclusively. Further mechanistic studies, along with Density Functional Theory (DFT)
suggest that the second protonation event is rate determining, and that the pendant hydrogen-bond
donors independently enhance CO2 reduction by guiding an acid molecule into the right
configuration to enable facile proton transfer.
In chapter four we will present the synthesis of a series of deprotonated cobalt
aminopyridine complexes. Structural studies suggest that charge is localized to the anionic
nitrogen atom and is not electronically coupled to the metal center. Electrochemical investigation
shown that the magnitude of charge in the second sphere corresponds to the reduction potentials
of the metal complex. Interestingly, the doubly deprotonated specie exhibits a well-behaved
reduction assigned for the Co
1/0
which becomes ill defined in the absence of protons, indicating
that the second reduction involves a proton transfer to or from the complex.
Finally, chapter five will present a series of organic syntheses to make three novel
aminopyridine ligands with electron withdrawing and donating substituents incorporated into the
pyridine ligands. Incorporation of electron donating NMe2 functional groups into two of the
pyridines in the ligand backbone gives rise to a 10-fold increase in the overall rate of catalysis with
only a minor decrease in selectivity. Electron withdrawing trifluoromethyl groups (CF3), on the
other hand, hinder catalysis and bring upon a decrease in selectivity, giving rise to production of
both CO and H2 at 15% faradaic efficiency for both. Finally, integration of both NMe2 and CF3
functional groups into the same ligand scaffold gives rise to a rate increase with respect to CO2 but
also a decrease in selectivity and stability overtime. DFT calculations show that the electron
density on the metal is proportional with the propensity of the CO2 ligand to get protonated. Thus,
electronic modifications on the first coordination sphere have an impact on proton transfer.
19
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26
Chapter 2
Hydrogen bond assisted reduction of CO2 by a cobalt aminopyridine complex
A portion of this chapter has appeared in print:
Chapovetsky, A.; Do, T. H.; Haiges, R.; Takase, M. K; Marinescu, S. C.* “Proton Assisted Reduction of CO 2 by
Cobalt Aminopyridine Macrocycles” J. Am. Chem. Soc. 2016, 138, 5765–5768. DOI: 10.1021/jacs.6b01980
27
2.1 Introduction
Carbon dioxide has received attention as an abundant, economical, and renewable
C1 feedstock, and its catalytic conversion to liquid fuels could positively impact the global
CO2 balance
2,3,6,95
. Much work has gone into developing molecular catalysts for
CO2 reduction from inexpensive elements for applications in efficient, scalable energy storage
2-
4,6,95-97
. However, despite promising results in CO2 reduction, many of these species perform
catalysis with low energetic efficiencies and/or low selectivity. Consequently, the development of
molecular systems that catalyze the reduction of CO2 remains a major challenge. In nature, the
selective and reversible conversion of CO2, protons, and reducing equivalents into CO is catalyzed
by the enzyme CO-dehydrogenase (CODH), which contains multi-metallic active sites
2,98
. An
intermediate in the catalytic cycle of the Ni,Fe-CODH has been characterized by X-ray diffraction
(XRD) studies, showing that the CO2fragment bridges between Ni and Fe
37
. CO2 binds to Ni via
the C atom and to Fe via one of the carboxylate oxygen atoms. Moreover, the oxygen groups are
involved in H-bonding interactions with protonated histidine and lysine residues. Thus,
CO2 binding and catalysis in the enzyme appear to involve bifunctional activation by two metal
centers and additional stabilization from proton relays present in the second coordination sphere.
In a similar fashion, the pendant amine present in [FeFe]-hydrogenase was shown to assist in
proton-transfer steps and facilitate the hydrogen evolution reaction (HER)
2
. These architectural
features are instrumental in controlling the protein activity and have inspired the development of
molecular systems.
Mononuclear nickel phosphine complexes with pendant proximal bases were reported to
catalyze the reduction of protons with turnover frequencies above 100,000 s
–199
. The mechanism
of proton reduction and hydrogen oxidation involves the cooperative interaction of hydrogen with
both the metal center and multiple proton relays incorporated in the second coordination sphere,
similar to the ones found in hydrogenases
2,7,100,101
. These nickel phosphine complexes were also
reported to undergo the electrocatalytic oxidation of formate, and mechanistic studies demonstrate
that the pendant amine plays an important role in catalysis
99,102
. Oxa- and azadithiolate ligands
function as proton relays, indicated by the enhanced rates of proton reduction of these species
21
.
Recent studies have shown that modification of iron tetraphenylporphyrin through the introduction
of eight phenolic groups in all ortho and ortho′ positions of the phenyl groups enhance CO 2
electroreduction to CO. The basis of the enhanced activity was hypothesized to be the high local
28
concentration of protons associated with the phenolic hydroxyl substituents. High reactivities and
selectivities were also observed for the reduction of CO2 by manganese bipyridine complexes with
pendant phenols
103
. Manganese complexes that include a coordinated carboxamide as a proton
shuttle were reported to catalyze the O2 reduction. Other reactions have been recently facilitated
by noncovalent interactions between a substrate and the secondary sphere of transition-metal
complexes, such as iridium or iron species, which were reported to catalyze the hydrogenation of
CO2, the dehydrogenation of formic acid or alcohols, or both
104-110
. Metal complexes with pendant
borane groups were shown to facilitate the reductive coupling of CO and the dehydrogenation of
ammonia borane
111-113
.
We became interested in macrocyclic aminopyridine ligands, such as
azacalix[4](2,6)pyridines, due to the promising precedents in the CO2 reduction chemistry of
several pyridine
114-116
and macrocyclic complexes
2,3,6
. Macrocyclic compounds based on
azacalix[4](2,6)pyridines have been developed recently in the context of supramolecular host–
guest interaction and molecular recognition
116,117
. However, their catalytic properties have not
been explored. We report here the efficient reduction of CO2 by cobalt aminopyridine
macrocycles.
2.2 Results and Discussion
2.2.1 Synthesis and Characterization
Figure 2.1. Schematic depicting the synthesis of 1 and 2.
29
The desired ligands were prepared according to the reported literature procedures. Two
ligand derivatives with different substitutions on the pendant amines were employed. One where
R = H (L
1
) and one where R = Me (L
2
). Addition of cobalt(II) precursors to the macrocyclic
aminopyridines L
1–2
led to the formation of the corresponding metal complexes (1–2) in near
quantitative yields (Figure 2.1). Single crystal XRD studies of 1–2 reveal that the four pyridine
nitrogen atoms coordinate in a square planar fashion, with Co–N bond lengths of about 1.9(1) Å
(Figure 2.2). The counteranions are outside the coordination sphere. The azacalix[4](2,6)pyridine
ligands adopt a saddle conformation with approximate D2d symmetry, if the axial ligands are not
taken into account. Complexes 1 and 2 feature a solvent molecule(s) coordinated in the axial
position(s). The nonbonding Co–N (pendant amine) distances range between 2.9–3.1 Å.
Figure 2.2. Solid state crystal structures of 1 (A) and 2 (B). Side (left) and top (right) views are
depicted. Non-coordinating solvent molecules and anions are omitted for clarity.
To better understand the electrochemical reactivity, a reduced form of 1, 1
-
was made. The
addition of excess potassium graphite (KC8) to a solution of 1 in pyridine gave rise to a new specie
as verified by proton nuclear magnetic resonance spectroscopy. X-ray quality single crystals were
grown out of a pyridine ether solution. In the solid state, 1
-
is structurally akin to 1, with the four
ligand pyridines coordinated in a square planar fashion around the metal center and two pyridines
30
in the axial position (Figure 2.10). Only one BF4
-
anion is present indicating that the oxidation
state of the metal has been reduced. The oxidation change was also confirmed by Evans method,
with a µeff = 3.63 Bohr Magnetons (3 unpaired electrons), as opposed to a µeff = 2.92 Bohr
Magnetons (2 unpaired electrons) for the parent complex.
2.2.2 Electrochemical Studies
Cyclic voltammograms (CVs) of 1 using a glassy carbon electrode (GCE) in a
dimethylformamide (DMF) solution of 0.1 M [nBu4N][PF6] under a nitrogen atmosphere feature
a reversible peak at −1.65 V and an irreversible peak at −2.46 V (Figure 2.3, left). All the potentials
are listed versus Fc
+/0
. The couple at -2.46 V has a return oxidation at -1.75 V. The large separation
in the Co
I/0
couple is suggestive of a structural rearrangement upon reduction.
Figure 2.3. Electrochemical studies of 1. (a) CVs of 1 (0.5 mM) in 0.1 M [nBu4N][PF6] in DMF
under N2 (black and red) or CO2 (blue). (b) Linear scan voltammograms of 1 (0.5 mM) in 0.1 M
[nBu4N][PF6] in DMF under CO2 and varying concentrations of methanol. Scan rates: 100 mV/s.
To determine whether the observed reductions or ligand or metal based, a zinc analogue, [Zn(L
1
)][BF4]2, was synthesized and characterized electrochemically. No peaks were observed in the CVs
of the zinc analogue between 0 and -2.8 V, suggesting that the observed reduction events are metal
based (Figure 2.4, left). CV of 1
-
under an inert atmosphere show a single irreversible reduction
event at -2.46 V, indicating that the reduction at -1.65 V can be assigned to a Co
II/I
couple. The
feature at -2.46 V was assigned to the Co
I/0
couple (Figure 2.4, right, and Figure 2.11). Variable
Scan Rate (VSR) experiments on the Co
II/I
couple and a plot of the peak current versus the square
31
root of the scan rate suggests that the reduction even is molecular and not heterogeneous (Figure
2.5).
Figure 2.4. Cyclic voltammograms of the parent complex (red) and (A) the zinc analogue (blue)
and (B) the reduced specie 1
-
(black)
Figure 2.5. (A) Cyclic voltammograms of 0.5 mM (1) in a DMF solution containing 0.1 M
[nBu4N][PF6] under an atmosphere of N2 displaying the reversible one-electron reduction with an
E1/2 of –1.59 V vs. Fc
+/0
and assigned to [Co(L
1
)]
2+/+
couple. Scan rates vary from 0.025 to 1 V/s.
and (B) Plot showing that the peak current, both cathodic and anodic, in the cyclic voltammograms
(CVs) of 0.5 mM (1) in a DMF solution containing 0.1 M [nBu4N][PF6] under an atmosphere of
N2. The cathodic and anodic peak currents increase linearly with the square root of the scan rate.
This behavior is indicative of a freely-diffusing species, where the electrode reaction is controlled
by mass transport.
CVs of 1 under CO2 (1 atm) exhibit enhanced currents at potentials near that of the Co
I/0
reduction (Figure 2.3, left). Addition of weak Brønsted acids such as 2,2,2- trifluoroethanol (TFE)
(Figure 2.3, right) to 1 resulted in large increases in current. A current density of 10 mA/cm
2
was
achieved at −2.70 V in the presence of 1 (0.5 mM), TFE (1.5 M), and CO2 (1 atm) (Figure 2.3,
32
right). This current increase corresponds to the reduction of CO2 to CO, as verified by controlled
potential electrolysis (CPE), vida infra. The normalized peak catalytic current (icat/ip) is related
to the TOF of the catalytic reaction, which is 16,900 s
-1
, as derived from CV data using the reported
formula (Experimental conditions). Similar currents are observed in other solvents, such as a 1:4
mixture of DMF and acetonitrile and dimethyl sulfoxide (DMSO) (Figures 2.12-2.14). CVs in the
absence of catalyst or CO2 exhibit no current increase indicating that the activity is not due to the
blank GCE or to proton reduction (Figure 2.15). Catalytic current densities increase linearly with
catalyst loading, and [CO2], consistent with a reaction that is first order in both substrates (Figures
2.5 and 2.20). Titration of 1 with CO2, both in the presence and absence of an external proton
source show a positive shift in onset with increasing CO2 concentration, indicating that the initial
binding to CO2 is thermodynamically favorable and not rate determining (Figured 2.16-2.17).
Finally, titration of 1 with TFE-d3 gave rise to increased currents lower than those of 1 and proteo-
TFE, with a Kinetic Isotope Effect (KIE) of 1.48, indicating that a protonation is rate determining
(Figure 2.19-2.20).
Figure 2.6. Plot of the observed rate constants kobs vs. (a) [TFE] and [TFE-d3], (b) [CO2] and (c)
[1] in a DMF solutions containing 0.1 M [nBu4N][PF6]. For each figure, the substrates not titrated
33
are at saturation (0.5 mM 1, 0.2 M CO2, and 1.5 M TFE). The linear dependence of the observed
rates on the titrants is consistent with reactions that are first order in [TFE], [CO 2], and [1]. The
ration of the slopes for the [TFE] and [TFE-d3] produces a kinetic isotope effect of 1.48.
Complex 2 was studied in a similar manner as 1. Reduction under an N2 atmosphere shows
a reversible peak at -1.41 V and an irreversible peak at -2.58 V corresponding to the Co
II/I
and Co
I/0
couples, respectively. For complex 2, the Co
I/0
reduction event does not have a return oxidation.
The shifts in the potentials for complex 2 are due to both electronic influence from the ligand and
solvation phenomena brought upon by methylation. This has been discussed elsewhere. Under an
atmosphere of CO2, 2 exhibits enhanced currents with onsets at -2.10 V and a maximum at -2.40
V attributed to CO2 reduction (Figure 2.7, c). The current increases as a function of [TFE],
however, the maximum current densities obtained at 1.5 M are at 0.8 mA/cm
2
, giving rise to an
overall rate of 20 s
-1
, significantly lower than that of 1. This result indicates that methylation of all
the amines inhibits the reactivity towards CO2.
Figure 2.7. Electrochemical studies of 2. (a) CVs of 2 (0.5 mM) in 0.1 M [nBu4N][PF6] in DMF
under N2 (black and red) or CO2 (blue). (b) Linear scan voltammograms of 2 (0.5 mM) in 0.1 M
[nBu4N][PF6] in DMF under CO2 and varying concentrations of methanol Scan rates: 100 mV/s.
(c) observed rate constants kobs vs. [TFE].
34
2.2.3 Controlled Potential Electrolysis
Controlled potential electroslysis of 1 (0.5 mM) was performed at a potential of -2.75 V in
a DMF solution containing [nBu4N][PF6] (0.1 M) and TFE (1.2 M) under CO2 atmosphere (0.2
M). 31.0 columbs were consumed after 2 h (Figure 2.8).
Figure 2.8. Overlay of current (a) and charge (b) traces for controlled potential electrolysis (CPE)
experiments for complexes 1 and 2 measured at –2.7 V vs. Fc
+/0
over 2 hours. Electrochemical
studies are performed in DMF solutions containing 0.1 M [nBu4N][PF6] under an atmosphere of
CO2 and in the presence of 2,2,2-trifluoroethanol (1.2 M) (dashed black), and catalyst (0.5 mM
each).
Analysis of the gas mixture in the headspace of the working compartment of the
electrolysis cell by gas chromatography confirmed production of CO with a Faradaic efficiency
(FE) of 98 ± 2% and a total TON (molCO/ molcat.) of 11 (Table 2.1). Only trace amounts of H2
were detected. The liquid phase was also analyzed, but no CO containing products were detected.
Additionally, trace amounts of CO were detected in the headspace of the auxiliary electrode
compartment of the CPE cell. Negligible current densities and CO amounts were observed using
the cobalt(II) starting material or in the absence of 1. Complex 1 affords a continuous increase in
the charge build-up over the course of 2 h, suggesting that 1 is moderately stable in longer-duration
CPE. The GCE used in the CV or CPE experiments of 1 was rinsed with DMF (3 × ), and its
electrochemistry was measured in fresh DMF solutions (Figure 2.20). Very low current densities
were observed, suggesting that complex 1 does not deposit on the GCE during catalysis to generate
a modified electrode active for the reduction of CO2. Additionally, CPE of 1 in the presence of
mercury showed no change in catalytic activity, suggesting that 1 does not generate cobalt particles
active for catalysis.
35
CPE experiments on 2 show the production of a significantly lower amount of current over
the course of two hours (Figure 2.8). Headspace analysis reveals the presence of CO but only in
36% faradic efficiency, suggestive of other processes occurring in solution. Trace amounts of H 2
were detected in the headspace and no formate was detected in the working compartment solution.
The electrode washing experiment was performed post CPE to show that 2 does not get deposited
onto the electrode. We suspect that the low faradaic efficiency for this molecule is due to other
processes such as oxidative quenching between 2 and its reduced form in solution.
2.2.4 Mechanistic Insights
Figure 2.9. Proposed catalytic cycle for 1 for the reduction of CO2-to-CO
A proposed mechanism for the reduction of CO2 to CO by 1 is illustrated in Figure 2.9.
Complex 1 is reduced by one electron to generate 1
-
. This is confirmed by both electrochemical
and stoichiometric methods. 1
-
can be reduced further to make the Co
0
derivative. Enhanced
currents are observed at potentials near the Co
I/0
couple upon addition of CO2, suggesting that the
36
two-electron reduced version of 1 can bind CO2 to make intermediate 3. CO2 was shown
previously to coordinate to a cobalt(I) tetraazamacrocyclic complex and form a CO 2 adduct that
has been spectroscopically characterized
6,118
. IR studies performed by Fujita et al. indicate the
presence of intramolecular H-bonding between bound CO2 and the macrocycle in solution at low
temperature
118,119
. In a similar fashion we propose that hydrogen bonds play a role in either
stabilizing fragment 3 or facilitating proton transfer, which is rate determining in this reaction. For
tertiary amines, as in the case of complex 2, this stabilization cannot occur, which agrees with our
experimental results. Species 3 can then undergo a two-electron transfer to generate [Co(L
1
)
(CO2
2–
)]. This type of intermediate was observed by Fujita et al. for a cobalt tetraazamacrocyclic
complex using XANES
119
. In the presence of protons this intermediate is converted into a metal-
CO2H species (4). Proton-promoted C–OH bond cleavage gives a carbonyl complex, which
subsequently dissociates CO to regenerate the starting material 1.
In summary, several cobalt macrocyclic compounds based on azacalix[4](2,6)pyridines
have been synthesized, and their electrocatalytic properties were explored. Complex 1 catalyzes
the reduction of CO2 to CO with excellent Faradaic efficiency. Our studies indicate that the cobalt
system with pendant NH groups is at least 2 orders of magnitude more efficient than the systems
with NMe groups. Mechanistic studies of the CO2 reduction by cobalt aminopyridine systems are
soon to follow.
37
2.3 Experimental Details and Additional Figures.
2.3.1 General
All manipulations of air and moisture sensitive materials were conducted under a nitrogen
atmosphere in a Vacuum Atmospheres drybox or on a dual manifold Schlenk line. The glassware
was oven-dried prior to use. All solvents were degassed with nitrogen and passed through activated
alumina columns and stored over 4Å Linde-type molecular sieves. Deuterated solvents were dried
over 4Å Linde-type molecular sieves prior to use. Proton NMR spectra were acquired at room
temperature using Varian (Mercury 400 2-Channel, VNMRS-500 2-Channel, VNMRS- 600 3-
Channel, and 400-MR 2-Channel) spectrometers and referenced to the residual 1 H resonances of
the deuterated solvent (
1
H: CDCl3, δ 7.26; C6D6, δ 7.16; CD2Cl2, δ 5.32; CD3CN, δ 2.94) and are
reported as parts per million relative to tetramethylsilane. Elemental analyses were performed
using Thermo Scientific™ FLASH 2000 CHNS/O Analyzers. All the chemical reagents were
purchased from commercial vendors and used without further purification. The ligands L
1–2
were
prepared according to the reported literature procedures
116,120
.
2.3.2 Cyclic Voltammetry (CV)
Electrochemistry experiments were carried out using a Pine potentiostat. The experiments
were performed in a single compartment electrochemical cell under nitrogen or CO2 atmosphere
using a 3 mm diameter glassy carbon electrode as the working electrode, a platinum wire as
auxiliary electrode and a silver wire as the reference electrode. Ohmic drop was compensated using
the positive feedback compensation implemented in the instrument. All experiments in this paper
were referenced relative to ferrocene (Fc) with the Fe
3+/2+
couple at 0.0 V. Alternatively, in cases
when the redox couple of ferrocene overlapped with other redox waves of interested,
decamethylferrocene (Fc*) was as an internal standard with the Fe*
3+/2+
couple at –0.48 V. All
electrochemical experiments were performed with 0.1 M tetrabutylammonium
hexafluorophosphate as supporting electrolyte. The concentrations of the cobalt complexes 1
(II)
–
6
(II)
were generally at 0.5 mM and experiments with CO2 were performed at gas saturation or
varying amounts of CO2 in dimethylformamide (DMF).
38
2.3.3 Controlled-potential electrolysis (CPE)
CPE measurements were conducted in a two-chambered H cell. The first chamber held
the working and reference electrodes in 50 mL of 0.1 M tetrabutylammonium hexafluorophosphate
and 0.5 M methanol in DMF. The second chamber held the auxiliary electrode in 25 mL of 0.1 M
tetrabutylammonium hexafluorophosphate in DMF. The two chambers were separated by a fine
porosity glass frit. The reference electrode was placed in a separate compartment and connected
by a Vycor tip. Glassy carbon plate electrodes (6 cm × 1 cm × 0.3 cm; Tokai Carbon USA) were
used as the working and auxiliary electrodes. Using a gas-tight syringe, 10 mL of gas were
withdrawn from the headspace of the H cell and injected into a gas chromatography instrument
(Shimadzu GC-2010-Plus) equipped with a BID detector and a Restek ShinCarbon ST
Micropacked column. Faradaic efficiencies were determined by diving the measured CO produced
by the amount of CO expected based on the charge passed during the bulk electrolysis experiment.
For each species the controlled-potential electrolysis measurements were performed at least twice,
leading to similar behavior. The reported Faradaic efficiencies and mmol of CO produced are
average values.
2.3.4 TOF calculations from cyclic voltammetry
Equations 1–5 were used to determine TOF from catalytic CVs
121
. The peak catalytic
current (icat) for an EECC process (E = electrochemical, C = chemical step) is given by eq 1, and
it corresponds to the plateau current. This equation assumes a one-electron diffusion current and
pseudo-first-order kinetics (the reaction is first order in catalyst and the concentrations of the
substrates, Q (CO2), is large in comparison to the concentration of catalyst). In eq 1, F is Faraday’s
constant (F = 96 485 C/mol), S is the surface area of the electrode (A = 0.07065 cm
2
for CVs),
𝐶 𝑐𝑎𝑡 0
is the catalyst concentration ([cat] = 0.5 mM = 5 × 10
–7
mol/cm
3
), Dcat is the diffusion constant
of the catalytically-active species (~5 × 10
–6
cm
2
/s), and kcat
is the rate constant of the catalytic
reaction.
𝑖 𝑐𝑎𝑡 = 𝐹𝑆 𝐶 𝑐𝑎𝑡 0
√𝐷 𝑐𝑎𝑡 √2𝑘 𝑐𝑎𝑡 (1)
39
Equation 1 is simplified by standardizing with the current in the absence of substrate (CO2
in this case), as described by eq 2. In eq 2, F is Faraday’s constant (F = 96 485 C/mol), S is the
surface area of the electrode (A = 0.07065 cm
2
for CVs), 𝐶 𝑐𝑎𝑡 0
is the catalyst concentration ([cat]
= 0.5 mM = 5 × 10
–7
mol/cm
3
), Dcat is the diffusion constant of the catalytically-active species (~5
× 10
–6
cm
2
/s), υ is the scan rate (0.1 V/s), R is the universal gas constant (R = 8.31 J K
–1
mol
–1
),
and T is temperature (T = 298.15 K).
𝑖 𝑝 = 0.446 × 𝐹𝑆 𝐶 𝑐𝑎𝑡 0
√𝐷 𝑐𝑎𝑡 √
𝐹𝜐
𝑅𝑇
(2)
Dividing eq 1 by eq 2 allows for determination of icat/ip and allows one to further calculate
the catalytic rate constant (kcat) without having to determine S, 𝐶 𝑐𝑎𝑡 0
, and Dcat. The ratio of equations
1 and 2 produces equation 3 which can be rearranged to produce equation 4 in which kcat can be
solved directly.
𝑖 𝑐𝑎𝑡
𝑖 𝑝 =
1
0.446
× √
2𝑘 𝑐𝑎𝑡
𝜐 𝑅𝑇
𝐹 = 2.24 × √
2𝑘 𝑐𝑎𝑡
𝜐 𝑅𝑇
𝐹 (3)
𝑘 𝑐𝑎𝑡 = (
𝑖 𝑐𝑎𝑡
𝑖 𝑝 )
2
𝜐 2.24
2
𝐹 2𝑅𝑇
(4)
Finally, eq 4 can be simplified into eq 5, from which kcat can be calculated directly.
𝑘 𝑐𝑎𝑡 = 0.387 × (
𝑖 𝑐𝑎𝑡
𝑖 𝑝 )
2
(5)
2.3.5 TOFCPE calculations from controlled potential electrolysis
121
Equation 6 was used to determine TOF from CPE data, as previously reported
120
. This
equation assumes that electron transfer to the catalyst is fast, obeying the Nernst law. In eq 6, i is
the stable current transferred during CPE (i = charge*F.E./time, C/s), F is Faraday’s constant (F =
96 485 C/mol), A is the surface area of the working electrode (A = 3 cm
2
for CPE), kcat is the
overall rate constant of the catalytic reaction, D is the diffusion coefficient (~5 × 10
–6
cm
2
/s), [cat]
is the concentration of the catalyst without substrate ([cat] = 0.5 mM = 5 × 10
–7
mol/cm
3
), R is the
universal gas constant (R = 8.31 J K
–1
mol
–1
), T is temperature (T = 298.15 K), F/RT = 38.92 V
–1
.
40
When the electrolysis potential is on the plateau of the catalytic wave, the following eq can be used
to calculate TOF, as previously reported
121
.
𝑇𝑂𝐹 = 𝑘 𝑐𝑎𝑡 =
𝑖 2
𝐹 2
𝐴 2
𝐷 [𝑐𝑎𝑡 ]
2
(6)
2.3.6 Evan’s Method
122
Evan’s method was used to determine the total spin (S) of a metal complex by
1
H NMR
spectroscopy. Equation 7 is used to determined the MMs (Measured Molar Susceptibility). ΔHz
is the difference in hertz between the peaks of the solvent in contact with the complex and the ones
in the capillary tube and, M is the molarity of the sample (in units of mol/L), and Hz NMR is the
spectrometer frequency, in hertz (500,000,000).
𝑀𝑀𝑠 =
3000 × 𝛥𝐻𝑧 4𝜋 ×𝑀 ×𝐻𝑧
𝑁𝑀𝑅
(7)
• For 1
(II)
, ΔHz = 90.5 Hz
• For 1
(I)
, ΔHz = 131.5 Hz
Subsequently, eqs 8 and 9 are used to determine the number of unpaired electrons
𝑋 𝑃 = 𝑀𝑀𝑠 − 𝑋 𝐷 , 𝑋 𝐷 =
𝑚𝑀
2
× 10
−6
(8)
𝜇 𝑒𝑓𝑓 = 2.84√𝑇 × 𝑋 𝑃 (9)
ΧP corresponds to the corrected molar susceptibility, mM is the molar mass of the sample (in
units of g/mol), and T is the temperature in Kelvin (293 K)
• For 1
(II)
mM = 720g/mol
• For 1
(I)
, mM = 513 g/mol
• The value obtianed for µeff:
41
o 1
(II)
is: 3.63 Bohr Magnetons. Three unpaired electrons correspond to an expected
value of 3.87
o 1
(I)
is: 2.92 Bohr Magnetons. Two unpaired electrons correspond to an expected
value of 2.83
2.3.7 Synthesis
[Co(L
1
)(acetone)2][BF4]2 (1). [Co(H2O)6][BF4]2 (14.3 mg, 0.0419 mmol) in acetone (1 mL) was
added to a solution of L
1
(15.6 mg, 0.0423 mmol) in acetone (2 mL) giving rise to a brown solution.
The mixture was allowed to stir for 5 minutes. The solution was filtered through a microfiber filter.
Slow diffusion with diethyl ether produced orange crystals in quantitative yields.
1
H NMR (400
Hz, MeCN-d3) δ 35.88 (s, 8H, m-NC5H3), 14.07 (s, 4H, p-NC5H3), 3.01 (s, 4H, NH). Anal. calcd
for [Co(L
1
)][BF4]2·3MeCOMe·0.5H2O (C29H36B2CoF8N8O4): C, 43.78; H, 4.57; N, 14.13. Found:
C, 43.91; H, 4.11; N, 14.53.
[Co(L
2
)(MeCN)][BF4]2 (2). [Co(H2O)6][BF4]2 (14.3 mg, 0.0419 mmol) in acetone (1 mL) was
added to a solution of L
2
(16.6 mg, 0.0391 mmol) in dichloromethane (2 mL) giving rise to a
brown solution. The mixture was allowed to stir for 5 minutes. The volatiles were removed under
vacuum, and the amber solid was dissolved in acetonitrile and the solution was filtered through a
microfiber filter. Slow diffusion with diethyl ether produced orange crystals in quantitative yields.
1
H NMR (400 Hz, MeCN-d3) δ 10.66 (s, 4H, p-NC5H3), 4.94 (s, 8H, m-NC5H3), 2.67 (s, 12H,
NMe). Anal. calcd for [Co(L
2
)][BF4]2·MeCOMe·MeCN (C31H36B2CoF8N10O): C, 46.81; H, 4.28;
N, 17.16. Found: C, 46.70; H, 4.55; N, 17.57.
[Zn(L
1
)][BF4]2. A solution of Zn(BF4)2 hydrate (11 mg, 0.032 mmol) in acetone (1 mL) was added
to a solution of L
1
(16.7 mg, 0.031 mmol) in acetone (2 mL) giving rise to an amber solution. The
mixture was allowed to stir for 5 minutes. Slow diffusion with diethyl ether produced amber
crystals in quantitative yields. 1 H NMR (500 Hz, MeCN- d3) δ 8.31 (s, 4H, NH), 7.85 (t, 4H, p-
NC5H3), 6.94 (s, 8H, m-NC5H3). Anal. calcd for [Zn(L
1
)][BF4]2·MeCOMe·(H2O)2
(C23H26B2ZnF8N8O3): C, 39.38; H, 3.74; N, 15.97. Found: C, 39.59; H, 3.25; N, 15.45
[Co(L
1
)(Pyridine)2][BF4] (1
-
). A solution of compound 1 (14 mg, 0.023 mmol) dissolved in
pyridine (2 mL) and cooled to –35 °C. The solution was added to cold KC8 (5.8 mg, 0.043 mmol).
The vial was capped and agitated for 30 seconds, giving rise to a green solution. The solution was
42
filtered to remove graphite and potassium tetrafluoroborate. Slow diffusion with diethyl ether
produced amber crystals in quantitative yields. 1 H NMR (500 Hz, pyridine-d5) δ 33.39 (s, 8H, m-
NC5H3), 11.2 (s, 4H, p-NC5H3), 4.84 (s, 4H, NH). Anal. calcd for [Co(L
1
)][BF4]·(C5H5N)3
(C35H31BCoF4N11): C, 55.94; H, 4.16; N, 20.5. Found: C, 55.95; H, 4.00; N, 18.61.
2.3.8 Additional Figures and Data
Figure 2.10. Top (left) and side (right) views of the solid-state structure of complex 1
-
.
43
Figure 2.11. Linear scan voltammograms of 1
-
(0.5 mM) in a DMF solution containing 0.1 M
[nBu4N][PF6] under an atmosphere of CO2 and in the presence of varying concentrations of 2,2,2-
trifluoroethanol. Scan rates are 100 mV/s.
Figure 2.12. Cyclic voltammogram of 0.5 mM of 1 in a 1:4 mixture of DMF:acetonitrile solutions
containing 0.1 M [nBu4N][PF6] under an atmosphere of N2 (red) or CO2 (blue). Scan rate is 100
mV/s.
Figure 2.13. Cyclic voltammogram of 0.5 mM 1 in a 1:4 mixture of DMF:acetonitrile solutions
containing 0.1 M [nBu4N][PF6] under an atmosphere of CO2 with 0.5 M MeOH (red), and in the
absence of methanol (blue), or catalyst (black dashed). Scan rate is 100 mV/s.
44
Figure 2.14. Cyclic voltammogram of 0.2 mM (1) in a DMSO solution containing 0.1 M
[nBu4N][PF6] under an atmosphere of N2 (blue), CO2 (red), and CO2 with 0.5 M MeOH (green).
Scan rate is 100 mV/s.
Figure 2.15. Cyclic voltammogram of DMF solution containing 0.1 M [nBu 4N][PF6] under
varying conditions. Controls show that activity necessitates 1, CO2, and protons and cannot
procced otherwise.
45
Figure 2.16. Linear scan voltammograms of 1 (0.5 mM) in a DMF solution containing 0.1 M
[nBu4N][PF6] under an atmosphere of N2 and in the presence of varying concentrations of CO2.
Scan rates are 100 mV/s.
Figure 2.17. Linear scan voltammograms of 1 (0.5 mM) in a DMF solution containing 0.1 M
[nBu4N][PF6], TFE (1.2 M) and in the presence of varying [CO2]. Scan rates are 100 mV/s.
46
Figure 2.18. Linear scan voltammograms of a DMF solution containing 0.1 M [nBu4N][PF6], TFE
(1.2 M) and CO2 (0.2 M) in the presence of varying [1]. Scan rates are 100 mV/s.
TABLE
Figure 2.19. Linear scan voltammograms of 1 (0.5 mM) in a DMF solution containing 0.1 M
[nBu4N][PF6] under an atmosphere of CO2 and in the presence of varying concentrations of TFE
(solid) and TFE-d3 (dashed). Scan rates are 100 mV/s.
47
Figure 2.20. Plot of the Log of the observed rate constants kobs vs. the Log values of (a) [TFE] and
[TFE-d3], (b) [CO2] and (c) [1] in a DMF solutions containing 0.1 M [nBu4N][PF6]. For each
figure, the substrates not titrated ar e at saturation (0.5 mM 1, 0.2 M CO2, and 1.5 M TFE). The
slopes of the lines are equal to one, indicating a first order dependence on the titrants.
Figure 2.20. Cyclic voltammograms of (A) 1 and (B) 2 (0.5 mM) in a DMF solution containing
[nBu4N][PF6] (0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1 atm) before (green) and after
(blue) controlled potential electrolysis (CPE). After the controlled potential electrolysis, the
working electrode was rinsed (3 × 10 mL DMF) and its electrochemistry was measured in a fresh
DMF solution containing [nBu4N][PF6] (0.1 M), 2,2,2-trifluoroethanol (0.6 M), and CO2 (1 atm)
– red. Scan rate is 100 mV/s.
48
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(21) Chakraborty, S.; Patel, Y. J.; Krause, J. A.; Guan, H. Catalytic properties of nickel
bis(phosphinite) pincer complexes in the reduction of CO2 to methanol derivatives.
Polyhedron 2012, 32, 30.
(22) Sharninghausen, L. S.; Mercado, B. Q.; Crabtree, R. H.; Hazari, N. Selective conversion
of glycerol to lactic acid with iron pincer precatalysts. Chemical Communications 2015, 51
(90), 16201.
(23) Hull, J. F.; Himeda, Y.; Wang, W.-H.; Hashiguchi, B.; Periana, R.; Szalda, D. J.;
Muckerman, J. T.; Fujita, E. Reversible hydrogen storage using CO2 and a proton-
switchable iridium catalyst in aqueous media under mild temperatures and pressures.
Nature Chemistry 2012, 4, 383.
(24) Miller, A. J. M.; Labinger, J. A.; Bercaw, J. E. Reductive Coupling of Carbon Monoxide
in a Rhenium Carbonyl Complex with Pendant Lewis Acids. J. Am. Chem. Soc. 2008, 130,
11874.
(25) Fulmer, G. R.; Miller, A. J. M.; Sherden, N. H.; Gottlieb, H. E.; Nudelman, A.; Stoltz, B.
M.; Bercaw, J. E.; Goldberg, K. I. Organometallics 2010, 29, 2176.
(26) Conley, B. L.; Pennington-Boggio, M. K.; Boz, E.; Williams, T. J. Discovery,
Applications, and Catalytic Mechanisms of Shvo’s Catalyst. Chem. Rev. 2010, 110, 2294.
(27) Hawecker, J.; Lehn, J. M.; Ziessel, R. Photochemical and Electrochemical Reduction of
Carbon Dioxide to Carbon Monoxide Mediated by (2,2′-
Bipyridine)tricarbonylchlororhenium(I) and Related Complexes as Homogeneous
Catalysts. Helv. Chim. Acta 1986, 69, 1990.
(28) Smieja, J. M.; Kubiak, C. P. Re(bipy-tBu)(CO)3Cl - improved Catalytic Activity for
Reduction of Carbon Dioxide: IR-Spectroelectrochemical and Mechanistic Studies. Inorg.
Chem. 2010, 49, 9283.
(29) Zhang, E.-X.; Wang, D.-X.; Huang, Z.-T.; Wang, W.-H. Synthesis of (NH)m(NMe)4−m-
Bridged Calix[4]pyridines and the Effect of NH Bridge on Structure and Properties. J. Org.
Chem. 2009, 74, 8595.
(30) Miyazaki, S.; Koga, Y.; Matsumoto, T.; Matsubara, K. A new aspect of nickel-catalyzed
Grignard cross-coupling reactions: selective synthesis, structure, and catalytic behavior of
50
a T-shape three-coordinate nickel(i) chloride bearing a bulky NHC ligand. Chem. Commun.
2010, 46, 1932.
(31) Fujita, E.; Creutz, C.; Sutin, N.; Brunschwig, B. S. Carbon Dioxide Activation by Cobalt
Macrocycles. Evidence of Hydrogen Bonding between Bound CO2 and the Macrocycle in
Solution. Inorg. Chem. 1993, 32, 2657.
(32) Fujita, E.; Furenlid, L. R.; Renner, M. W. Direct XANES evidence for charge transfer in
Co-CO2 complexes. J. Am. Chem. Soc. 1997, 119, 4549.
(33) Chapovetsky, A.; Do, T. H.; Haiges, R.; Takase, M. K.; Marinescu, S. C. Proton-Assisted
Reduction of CO2 by Cobalt Aminopyridine Macrocycles. J. Am. Chem. Soc. 2016, 138,
5765.
(34) Costentin, C.; Drouet, S.; Robert, M.; Savéant, J.-M. Turnover Numbers, Turnover
Frequencies, and Overpotential in Molecular Catalysis of Electrochemical Reactions.
Cyclic Voltammetry and Preparative-Scale Electrolysis. J. Am. Chem. Soc. 2012, 134 (27),
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Large Paramagnetic Molecules. Journal of Chemical Education 1997, 74 (7), 815.
51
Chapter 3
Pendant Hydrogen-bond donors in cobalt catalysts independently enhance CO2 reduction
A portion of this chapter has appeared in print:
Chapovetsky, A.†; Welborn, M.†; Luna, J. M.; Haiges, R.; Miller III, T. F.*; Marinescu, S. C.* “Pendant
Hydrogen-Bond Donors in Cobalt Catalysts Independently Enhance CO 2 Reduction”, ACS Cent.
Sci. 2018, 4(3), 397–404
52
3.1 Introduction
The catalytic conversion of carbon dioxide (CO2) into chemical fuels holds promise for
mitigating the adverse effects of fossil fuels on the environment
2,6,7,123-128
. In nature, the selective
and reversible conversion of CO2 to carbon monoxide (CO) is catalyzed by the enzyme CO-
dehydrogenase (CODH) through the transfer of two electrons and two protons
2,98
. Binding and
catalysis of CO2 occurs through bifunctional activation by the two metal centers in the NiFe cluster
and additional stabilization through hydrogen bonding from appropriately positioned residues, as
revealed by structural studies of the active site
129
. These studies suggest that a transition-metal
center surrounded by ligands with pendant proton donors is an effective design motif for artificial
CO2 reduction catalysts.
Pendant proton donors also facilitate catalysis of the hydrogen evolution reaction (HER).
In nature, HER occurs at the FeFe-hydrogenase (FFH) active site, which – like CODH – exhibits
two metal centers surrounded by pendant proton donors
2,130
. In FFH, protons are shuttled to and
from the active metal center by the secondary amine of an azadithiolene moiety
131
. The structure
of this active site has inspired the development of nickel phosphine complexes bearing pendant
tertiary amines; these complexes have proven to be extremely active HER electrocatalysts, with a
mechanism that involves the cooperative interaction of H2 with both the metal center and the
pendant amines
7,95,101
.
Incorporation of pendant proton donors into molecular catalysts has only recently been
explored in the context of CO2 reduction. The electrochemical CO2-to-CO activity of iron
porphyrin and metal bipyridine complexes was shown to increase with the incorporation of
pendant phenol or trimethylanilinium moieties into the ligand scaffold
73,88,89,94,125,132-136
. The
prepositioned phenol groups were proposed to stabilize the initial Fe
(0)
-CO2 adduct through H-
bonding, as confirmed by density functional theory (DFT) studies, and to facilitate the
intramolecular protonation
88,133
. Nickel phosphine complexes bearing pendant tertiary amines
have been recently shown to catalyze the electrochemical conversion of CO 2 to formic acid, as
well as the reverse reaction
102,137,138
. Additionally, nickel and cobalt cyclam systems bearing four
secondary amines were shown to electrochemically convert CO2 into CO
6,53,55,123,124,128,139-142
. DFT
studies proposed that CO2 is activated through cooperative hydrogen-bonding interactions between
53
the Ni-bound substrate and the secondary amines in the ligand framework
55,60,128,143
.
Electrochemical studies of nickel complexes supported by mono-, di-, tri-, and tetra-methylated
cyclam ligands revealed that both the catalytic activity and faradaic efficiency for CO 2-to-CO
conversion decrease upon methylation of the ligand framework
55,60
. Hence, a direct correlation
between the number of pendant proton donors and the activity of the catalyst could not be
established.
We previously reported a cobalt complex bearing four pendant secondary amine (NH)
groups incorporated in the ligand scaffold that is an efficient electrocatalyst for the selective
reduction of CO2 to CO
144
. Methylation of all four secondary amines produces a 300-fold reduction
in activity, indicating that the pendant amines are important for catalysis
144
. Unlike the metal
cyclam series, the pendant amines lie completely outside of the primary coordination sphere of the
metal center, allowing for isolation of the role of pendant protons. In addition, our ligand
framework allows for discrete control over the number and configuration of the proton donors
present in the outer sphere of the metal center without impacting its primary coordination
environment
145
. These structural features enable us to decouple the roles of the first and second
coordination spheres in a systematic and well-controlled manner. In the current work, we
investigate an expanded series of cobalt aminopyridine compounds through the synthesis of mono-
, 1,2-di-, 1,3-di-, and tri-methylated ligand scaffolds (Figure 3.1). We combine experimental and
theoretical approaches to elucidate the mechanism by which these catalysts bind and reduce CO2
in an effort to isolate and quantify the effect of pendant amine protons on catalysis. This work
provides new design principles for tuning the effect of the second coordination sphere on CO 2
reduction.
Electrochemical reduction of 1 under varying concentrations of CO2 (0 to 0.2 M) gave rise
to current increases at potentials near that of Co
(I)
/Co
(0)
reduction. The potential corresponding to
the maximum current displayed a positive shift with increased [CO2]. This behavior is Nernstian
and suggestive of a thermodynamically favorable interaction between 1
(0)
and CO2, consistent with
the formation of a CO2-bound pre-association complex
144
. Titration of 1 with acid (2,2,2-
trifluoroethanol, TFE) under CO2 saturation gave rise to a series of plateaus with a maximum at –
2.7 V vs. Fc
+/0
. A plot of the catalytic rate constant, kobs, (See experimental section for details) vs.
54
[TFE], [CO2], and [1] showed a linear correlation, with slopes of 11,400 M
-1
S
-1
, 27,800 M
-1
S
-1
,
and 10,900 M
-1
S
-1
, respectively. A plot of Log (kobs) versus the log of [TFE], [CO2], and [1]
produced straight lines with slopes of 1, indicating that the reaction is first order in all three
substrates. Finally, titrations with TFE-d3 under CO2 saturation give rise to a H/D kinetic isotope
effect (KIE) of 1.4(2). This result suggests that protons are involved in the rate-limiting step (RLS).
To explain the 300-fold decrease in activity between complexes 1 and 6, we previously
proposed that CO2 binding and catalysis in complex 1 occurs through the formation of a Co
(0)
–
CO2 adduct, which is stabilized through two intramolecular H-bonding interactions from the
pendant secondary amines
144
. This stabilization cannot occur for 6, which lacks pendant secondary
amines. The current study provides additional kinetic analysis of complexes 1 and 6, as well as the
additional context of complexes 2–5, to elucidate the mechanism by which these catalysts bind
and reduce CO2.
3.2 Results and Discussion
3.2.1 Synthesis and Characterization
Figure 3.1. Syntheses of complexes 1
(II)
–6
(II)
. The oxidation state of the cobalt center in each
complex is indicated by the superscript.
Complexes 2
(II)
through 5
(II)
are synthesized using similar procedures to those reported for
complexes 1
(II)
and 6
(II)
(Figure 3.1)
144
. Single crystal X-ray diffraction studies reveal a consistent
2+
N
R
2
N N
Co
N N
Solv
N
N
N
R
4
R
1 R
3
Solv
N
R
2
N
N
N
N
N
N
N
R
4
R
3
R
1
Solv = solvent
R
i
= H or CH
3
1 2 3 4 5 6
[Co(H
2
O)
6
][BF
4
]
2
55
motif for all six complexes, with a cobalt metal center coordinated by four pyridines in a square
planar fashion (Figure 3.2). Complexes 1
(II)
–6
(II)
adopt a saddle conformation in which each set of
opposing amines points outwards from the face of the complex. There is little variance in the Co-
NPyridine and Co-NPendantAmine bond lengths (1.95(2) Å, and 3.06(4) Å on average, respectively)
among the complexes. The measured pKa values of complexes 1
(II)
–5
(II)
range between 2.48 and
3.10 (Table 3.1, 3.7). Given their acidity, complexes 1
(II)
–5
(II)
are expected to be singly
deprotonated in solution
146
.
Complex E1/2(CoL
2+/+
) vs.
Fc
+/0
E(CoL
+/0
) vs.
Fc
+/0
icat/ ip kobs (s
–1
) FE
(%)
p Ka
1 –1.65 –2.46 208.8 16,900 98 2.74
2 –1.66 –2.73 189.9 14,000 98 2.66
3 –1.53 –2.41 130.0 6,200 98 2.53
4 –1.52 –2.41 113.7 5,200 98 3.10
5 –1.44 –2.87 11.4 50 90 2.48
6 –1.41 –2.58 7.7 20 36 NA
Table 3.1. Parameters for complexes 1–6. Reduction potentials (E), normalized current densities
(icat/ip), catalytic rate constants (kobs), Faradaic Efficiencies (FE), and pKa values for complexes 1–
6.
3.2.2 Electrochemical Studies
Electrochemical characterization of complexes 1–6 under N2 reveals a reversible one-
electron reduction with E1/2 between –1.41 and –1.65 V vs. Fc
+/0
, attributed to the Co
(II)
/Co
(I)
couple (Figure 3.3, Table 3.1). An irreversible reduction feature is observed between –2.46 and –
2.87 V vs. Fc
+/0
and is attributed to the reduction of Co
(I)
to Co
(0)
. Under an atmosphere of CO2,
complexes 1-6 exhibit a current increase near the Co
I/0
potential, indicative of a reaction between
the two (Figure 3.4). All complexes exhibit a scan-rate independent, linear relationship between
the rate and [TFE], indicative of a reaction that is first order in [TFE] (Figure 3.5 and 3.13).
Controlled potential electrolysis (CPE) studies in the presence of 1.2 M TFE reveal that 1–5
produced CO with excellent faradaic efficiencies (≥ 90%) and turn over numbers (Figures 3.14-
3.18, Table 3.2); in contrast, complex 6 is a poor catalyst with low faradic efficiency (36%),
56
producing negligible amounts of CO. The titration results, coupled with results from CPE, indicate
that complexes 1–5 are competent catalysts, thus allowing for direct comparison of their catalytic
performance.
57
Figure 3.2. Side (left) and top (right) views of the solid-state structures of 2-5 (A-D)
58
Figure 3.3. Cyclic voltammograms of 2-5 (A-D) in a DMF solution displaying the reversible one-
electron reduction assigned to Co
II/I
couple (Left). And plots showing that the peak current, both
cathodic and anodic, in the cyclic voltammograms (CVs) of 2-5 (A-D) (right). The cathodic and
anodic peak currents increase linearly with the square root of the scan rate, indicative of a freely-
diffusing species.
59
Figure 3.4. Cyclic voltammograms of 0.5 mM of 2-5 (A-D) in a DMF solution containing 0.1 M
[nBu4N][PF6] under an atmospheres of N2 or CO2 . Scan rate is 100 mV/s.
Figure 3.5. Cyclic voltammograms of 0.5 mM of 2-5 (A-D) in a DMF solution containing 0.1 M
[nBu4N][PF6] under an atmospheres of N2 or CO2 . Scan rate is 100 mV/s.
60
The absence of a trend between the potential for max catalysis (-2.70 V) and the
arrangement of the pendant amines in (Figure 3.5) indicates that the difference in activity between
the complexes is not due to any electronic phenomena brought upon by methylation.
Figure 3.6. (A) Plot of the observed rate constants kobs vs. [TFE] for complexes 1–5 (0.5 mM) in
a DMF solution containing 0.1 M [nBu4N][PF6], and CO2 (0.2 M) at 100 mV/s. The linear
relationship indicates that the reaction is first order with respect to TFE. The slopes of the lines
correspond to the overall rate constant. The slopes are: 11,400, 10,257, 4,300, 3,600, 33, M
–1
s
–1
for complexes 1-5, respectively. (B) Experimental catalytic rate constants, kobs (s
–1
), as a function
of the number of pendant secondary amines for complexes 1–6 measured in the presence of 1.5 M
TFE and under CO2 saturation at a scan rate of 100 mV/s. Rates are obtained from the plateau
current. A linear fit (R
2
= 0.97) is shown in black for complexes 1–5.
The observed rates for complexes 1-5 also showcase a trend. As seen in figure 3.6, an
increase in the number of secondary amines brings about an increase in the observed rate across
all TFE concentrations. Interestingly, a linear correlation is observed between the catalytic rate
constant and the number of secondary amines on the metal complex for 1–5 (Figure 3.6),
suggesting that the pedant amines play a critical role in catalysis. Because the measured rates for
3 and 4 are similar, we hypothesize that the pendant secondary amines act in a non-cooperative
manner, since the differing orientation of the pendant amines in these complexes has no effect on
the catalytic rate. The rates in figure 3.6 vary linearly with the number of pendant amines minus
one, consistent with a model in which one pendant amine is singly deprotonated and unable to
donate a hydrogen bond; consequently, while complex 5 (which has only one secondary amine)
operates at the same rate as complex 6 and 100-fold slower than complexes 3 or 4.
The shape of the lines can also be used to provide insight regarding catalysis. Upon
scanning to more negative potentials, an increase in current indicates an increase in activity until
a maximum is reached. A plateau in the current (Figure 3.5A-B) is indicative of total catalysis,
61
where the observed rate corresponds to the intrinsic rate of the catalyst, independent of substrate
diffusion or depletion. However, an S shaped curve is indicative of catalysis that is inhibited by
substrate depletion or other side phenomenon (Figure 3.5C-D). Scanning at faster rates (Figure 3.7
and 3.19-3.21) alleviates substrate dependence giving rise to a plateau shape.
Figure 3.7. Plot of the observed rate constants kobs vs. [TFE] for complexes 3–5 (0.5 mM) in a
DMF solution containing 0.1 M [nBu4N][PF6], and CO2 (0.2 M) at 100 mV/s and 2000 mV/s. The
linear relationship and slope are scan rate independent. Slopes and scan rates are indicated in the
legend.
The shape of the CV curves for complexes 1-5 indicates that increased methylation brings
about a decrease in the proton concentration around the metal center. This is consistent with other
reports in which pedant phenol groups have been shown to increase the rate of catalysis of an iron
porphyrin complex by increasing the local proton concentration by two orders of magnitude.
Taken together, the experimental results begin to paint a picture of the CO2 reduction
mechanism. Linear rate dependence on both [CO2] and [TFE] indicates that the reaction is first
order in each, and the observation of a positive shift in onset potential with the addition of CO 2,
but not TFE, indicates favorable binding between the complex and CO2. The hydrogen kinetic
isotope effect (kH/kD) of 1.4 suggests that protons are involved in the RLS. Finally, the linear rate
dependence of the catalytic rate on the number of pendant secondary amines indicates that they
play a central role in the reaction mechanism. However, key mechanistic details remain
unresolved, including the precise way the pendant proton donors facilitate the catalytic
mechanism, the nature of the CO2 pre-association with the complex, and the competition between
62
inter- and intramolecular proton-transfer steps in the reduction of CO2; DFT calculations are
employed in the following sections to address these points.
3.2.3. Density Functional Theory
DFT calculations are used to examine the structure and energetics of the CO 2-bound pre-
association complex suggested by the electrochemical experiments. Initially focusing on 1, the
geometry of the CO2-bound complex is optimized in its various accessible oxidation states
(corresponding to 1
(II)
, 1
(I)
, and 1
(0)
for the unbound complex). Of these, only 1
(0)
has a stable
minimum when bound with CO2, consistent with the Nernstian shifts observed electrochemically.
In this bound complex, CO2 binds to the metal center via the carbon atom with a bond-length of
2.06 Å, with the pendant amines pointed away from the CO2 binding site. Upon binding, charge
transfers from the Co center to the CO2, leading to oxidation of the metal center to a +1 state and
a bent CO2 geometry like that of the gas-phase anion. The anionic character of the bound CO2 is
further supported by CHELPG charge analysis (Table 3.3).
We now examine the role of the pendant amine protons in CO2 binding. Previous studies
have shown that intramolecular hydrogen bonds can stabilize the bound CO2
88,133,147
. In principle,
such interactions are available in complex 1
(I)
–CO2, if the pendant secondary amines undergo
umbrella flipping to orient the proton towards the bound CO2. To test this possibility, we compute
the energetics and barriers for the conformational change associated with forming either one or
two hydrogen bonds between the pendant amine protons and the CO2 ligand. The structure without
intramolecular hydrogen bonds is the most stable, with formation of a single hydrogen bond
incurring a cost of 5.2 kcal/mol with a barrier of 10.7 kcal/mol, and with the second hydrogen bond
incurring a further 1.3 kcal/mol energy cost with a barrier of 7.2 kcal/mol (Figure 3.8). Factors
contributing to the unfavourability of hydrogen-bond formation include ring-strain in the ligand
scaffold, the need to rotate CO2 into a sterically unfavorable configuration, and the relatively weak
hydrogen-bond interactions. Although this mode of binding differs from that seen previously in
iron porphyrins
88
, it is confirmed by embedded multireference configuration interaction singles
and doubles calculations (see experimental). To examine the effect of methyl substitution on the
binding of CO2, we repeat the binding-energy calculations for complexes 2
(I)
–CO2 through 6
(I)
–
63
CO2. All six bound complexes are isostructural, with Co–C bond lengths ranging between 2.06
and 2.17 Å (Table 3.3). The possibility of intramolecular hydrogen bonding was also considered
in all five NH-containing complexes and was found to be similarly unfavorable in all cases.
Figure 3.8. Geometries and energies for intramolecular hydrogen bonding between CO 2 and the
amine protons in complex 1(0)-CO2.
In terms of CO2 binding, the main difference among complexes 1–6 is the degree to which
steric repulsions are incurred between CO2 and the methyl groups, which weakens CO2 binding.
Complex 1
(I)
–CO2 has a CO2 binding energy of 11.8 kcal/mol, whereas methylation of all four
secondary amines as in complex 6
(I)
–CO2 results in a binding strength of 0.4 kcal/mol (Figure 3.9).
These weakened binding strengths lead to reduced populations of X
(I)
–CO2 pre-association
complexes, which manifests as a multiplicative factor in the rate under the assumption that the
mechanism proceeds via a CO2-bound pre-association complex. Specifically, we expect the
catalytic rate to be exponential in the CO2 binding energy.
Figure 3.9. Experimental catalytic rate constants (log scale) versus computed CO2 binding energy
for complexes 1
(I)
–CO2 through 6
(I)
–CO2. The best-fit line (R
2
= 0.97) for complexes 1
(I)
–CO2
through 4
(I)
–CO2 is shown in black.
1
(0)
-CO
2
∆ = 0 kcal/mol
TS 1
∆ = 10.6 kcal/mol
1 H-bond
∆ = 4.0 kcal/mol
TS 2
∆ = 11.2 kcal/mol
2 H-bonds
∆ = 5.8 kcal/mol
64
Figure 3.9 tests the assumption that the catalytic mechanism proceeds via a CO2-bound
pre-association complex by plotting the relationship between the catalytic rate constant and the
computed CO2 binding energy for complexes 1–6. For the complexes that exhibit at least one
available pendant proton (i.e., 1–4), the rate is exponential with the CO2 binding energy, supporting
a mechanism that involves formation of CO2-bound pre-association complex. According to the
trend from complexes 1–4 in Figure 3.9, complexes 5 and 6 also bind CO2 sufficiently well to
perform catalysis. However, as is discussed in the next sections, complexes 5 and 6 are unable to
employ the same catalytic pathway as 1–4 due to the absence of an available pendant proton.
Following binding, CO2 must be twice protonated to complete the catalytic cycle. Previous
work on an analogous cobalt tetraazamacrocyclic complex indicates that this process proceeds
sequentially, with the first protonation forming a COOH ligand and the second protonation
cleaving the C–OH bond to form water and bound CO
148
. In this work, the previously discussed
experimental results suggest that a proton-involving step is rate-limiting for the overall catalytic
cycle. We now use computation to investigate the various available protonation pathways.
Reaction energies of X
(I)
–CO2 (X = 1–6) with a proton from solution to yield X
(II)
–CO2H are
computed with reference to the experimental free energy of solvation of the proton in DMSO (See
Experimental section). The overall energy of this reaction ranges from –9.0 kcal/mol (complex
1
(I)
–CO2) to –18.2 kcal/mol (complex 3
(I)
–CO2).
Having completed two reduction steps and a first protonation step, the catalytic cycle could
either involve further protonation (“EECC” mechanism, Figure 3, where E = electrochemical, C =
chemical step), or reduction of 1
(II)
–CO2H followed by protonation (“ECEC” mechanism, See
experimental for more details). Because the reduction of Co
(I)
to Co
(0)
is irreversible, these
mechanisms cannot be experimentally distinguished and calculations are instead employed. The
1-electron reduction potential of 1
(II)
–CO2H is calculated to be –2.9 V vs. Fc
+/0
, suggesting that
reduction of 1
(II)
–CO2H is not kinetically competent at the potential of maximum catalytic current
(–2.7 V vs. Fc
+/0
). This, along with precedent from the aforementioned results.
148
, suggests that
the EECC mechanism is dominant; the alternative ECEC mechanism is further detailed in (Figures
3.26-3.29). Proceeding along the EECC mechanism, the second protonation may occur either on
65
the protonated oxygen to form a CO(OH2) adduct or on the unprotonated oxygen to form a C(OH)2
adduct. Calculations for 1
(II)
–CO(OH2) and 1
(II)
–C(OH)2 show that the latter is less favorable by
26.4 kcal/mol, eliminating it from the catalytic pathway. After the second protonation, the C–OH
bond in X
(II)
–CO(OH2) spontaneously breaks, forming X
(II)
–CO and water. The energy of this
reaction ranges from –8.4 kcal/mol (complex 1
(II)
–CO2H) to –10.4 kcal/mol (complex 6
(II)
–
CO2H).
Figure 3.10. (A) Protonation energies of complexes 1
(I)
–CO2 through 6
(I)
–CO2 (blue) and 1
(II)
–
CO2H through 6
(II)
–CO2H (red) and (B) Calculated first protonation energy for complexes 1
(I)
–
CO2 through 6
(I)
–CO2 with (red) and without (blue) implicit solvent.
Figure 3.10A shows a comparison of the overall thermodynamic driving force between the
first and second protonation for complexes 1–6. The clustering of complexes 1 and 2 versus 3-6 is
believed to be due to solvation (Figure 3.10B). In all six complexes, the second protonation is less
favorable, consistent with previous studies on iron porphyrin complexes
88
. This result can be
understood as a difference in nucleophilicity between the CO2 and COOH intermediates, with the
CO2 ligand exhibiting greater anionic character (Tables 3.3 and 3.5). Though activation barriers
were not calculated, the Bell-Evans-Polanyi principle suggests that the energetically less favorable
second protonation will likewise have a slower reaction rate. In summary, we argue that X
(I)
–CO2
is twice protonated on the same oxygen via the EECC mechanism to form water and X
(II)
–CO,
with the second of these protonation steps constituting the RLS.
Having identified the second protonation of the CO2 ligand as the likely RLS, we now
investigate whether protonation is more favorable via an intra- vs. inter-molecular mechanism.
Our experimental observations constrain this mechanism in three ways, with (i) titrations
indicating that the RLS involves undissociated TFE, (ii) the overall catalytic rates for complexes
66
1–6 suggesting that the RLS involves the pendant secondary amines in a non-cooperative manner,
and (iii) the KIEs indicating that the RLS involves protons.
Figure 3.11. Two pathways for the rate-limiting protonation of complex 1
(II)
–CO2H. Geometries
of critical points are shown and labeled by their energies in kcal/mol. Below: side view of a key
intermediate from each pathway. Hydrogen bonds are labeled with dashed lines and their lengths
are given in Angstroms. Fluorine atoms are shown in green.
Two mechanisms consistent with these observations include intramolecular acid-assisted
proton transfer from the pendant amine to COOH and intermolecular pendant amine assisted
proton transfer from the acid to the COOH. For the intramolecular mechanism, proton transfer
follows rotation of the COOH ligand and umbrella-flipping of the pendant amine to form a
hydrogen-bonding geometry (Figure 3.11); this conformational rearrangement is energetically
uphill by 10.3 kcal/mol with a barrier of 15.2 kcal/mol, and the subsequent proton transfer step has
a barrier of 3.9 kcal/mol. The high energy barrier for reaching the intermediate disfavors this
mechanism, as does the fact that inclusion of a bound acid molecule in the calculations further
destabilizes the intermediate by 1.1 kcal/mol, contradicting the experimental trend of increasing
rate with increasing acid concentration (Figures 3.8 and 3.24).
67
To investigate the intermolecular proton-transfer mechanism, we consider the structure and
energetics of 1
(II)
–CO2H complex that contains a TFE molecule bridging the pendant amine and
COOH (Figure 3.11, blue box). Geometry optimization reveals a stable binding energy of 4.3
kcal/mol, and a short (1.81 Å) hydrogen bond, which suggests the favorability of intermolecular
proton-transfer to the COOH ligand. Note that the amine-acid hydrogen bond distance is too long
to support a shuttle mechanism in which a proton is transferred from the amine and to the acid
simultaneous with the proton transfer from the acid to the COOH ligand. We thus conclude that
the second protonation proceeds via direct proton transfer from TFE to the COOH ligand, assisted
by the pendant amine proton. Table 3.6 confirms that this analysis is consistent with the previous
section, indicating that all the corresponding barriers and intermediates shown in Figure 3.11 are
lower in energy when considering the first protonation step.
3.2.4 Mechanistic Insights
Figure 3.12. Proposed EECC catalytic cycle illustrated with complex 1, where E =
electrochemical, and C = chemical step.
–1
N
N N
Co
N N
N
N
N
H
H
H
C
O
O
N
N N
Co
N N
N
N
N
H
H
H
C
O
O
H
CF
3
O
H
1+
N
N N
Co
N N
N
N
N
H
H
H
C
O
–1
N
N N
Co
N N
N
N
N
H
H
H
1+
N
N N
Co
N N
N
N
N
H
H
H
2e
–
C
O
O
1
(II)
1
(0)
1
(I)
–CO
2
H
+
+ TFE
1
(II)
–CO
2
H TFE
TFE + H
2
O
C
O
H
+
rate limiting step
1
(II)
–CO
68
Figure 3.12 summarizes the proposed catalytic mechanism that emerges from the combined
analysis. Complex X
(II)
(X = 1–6) is reduced by two electrons and binds CO2 to yield X
(I)
–CO2.
The CO2 adduct is twice protonated, with the latter being rate-limiting and occurring via an
intermolecular mechanism that is non-cooperatively facilitated by the pendant amines. Finally, the
C–OH2 bond spontaneously cleaves to release water, and CO dissociates from X
(II)
–CO to
regenerate the catalyst. Given this mechanism, the overall catalytic rate constant for complex X
(kobs,X) is:
where kRLS is the rate constant of the RLS per pendant amine proton irrespective of X, (nX – 1) is
the number of available amine protons in X, [X] is the concentration of X, and ∆GX
b
is the free
energy of CO2 binding. The first grouping of terms summarizes the kinetics of the rate-limiting
step, and the second summarizes the binding of CO2 to form the pre-association complex. For the
rate-limiting step, each pendant amine can non-cooperatively bind an acid molecule, activating
and enhancing the local concentration of proton donors around the COOH adduct. The non-
cooperative nature of this hydrogen bonding makes the degree of catalytic enhancement dependent
only on the number of available pendant proton donors, such that kRLS is independent of the number
of pendant amines (Figure 3.6B). The second grouping of terms in the rate expression represents
the thermodynamics of CO2 binding to form the pre-association complex. As seen in Figure 3.8,
the experimental catalytic rate is exponentially related to the computed CO2 binding free energy
for complexes 1–4. This trend does not extend to complexes 5 and 6 where the first grouping of
terms sets the overall rate to zero, due to the absence of an available pendant proton.
3.3 Conclusion
We introduce and characterize a series of cobalt aminopyridine complexes that vary as a
function of the number of pendant proton donors and allow for the well-controlled analysis of
contributions from the first and second coordination spheres in CO2 reduction catalysis.
Electrochemical studies show that the CO2 reduction activity of these complexes depends strongly
69
on the number of secondary amines incorporated in the ligand framework. The observed linear
dependence of the rate of catalysis on the number of pendant proton donors has not been previously
reported for either CO2 reduction or hydrogen evolution. Computational studies reveal the
mechanism by which the pendant amines facilitate rate-limiting intermolecular proton transfer via
non-cooperative hydrogen bonds to acid in solution. By enabling systematic control over the
number of proton relays present in the second coordination sphere, the reported complexes provide
a relevant model for biological systems and homogenous catalysts for small molecule activation.
Furthermore, these complexes offer a framework for tuning the effect of the second coordination
sphere on CO2 reduction, and more generally, on multi-electron, multi-proton reduction reactions.
70
3.4 Experimental Details and Additional Figures.
3.4.1 General
All manipulations of air and moisture sensitive materials were conducted under a nitrogen
atmosphere in a Vacuum Atmospheres drybox or on a dual manifold Schlenk line. The glassware
was oven-dried prior to use. All solvents were degassed with nitrogen and passed through activated
alumina columns and stored over 4Å Linde-type molecular sieves. Deuterated solvents were dried
over 4Å Linde-type molecular sieves prior to use. Proton NMR spectra were acquired at room
temperature using Varian (Mercury 400 2-Channel, VNMRS-500 2-Channel, VNMRS- 600 3-
Channel, and 400-MR 2-Channel) spectrometers and referenced to the residual 1 H resonances of
the deuterated solvent (
1
H: CDCl3, δ 7.26; C6D6, δ 7.16; CD2Cl2, δ 5.32; CD3CN, δ 2.94) and are
reported as parts per million relative to tetramethylsilane. Elemental analyses were performed
using Thermo Scientific™ FLASH 2000 CHNS/O Analyzers. All the chemical reagents were
purchased from commercial vendors and used without further purification. The ligands L
1–6
and
complexes 1
(II)
and 6
(II)
were prepared according to the reported literature procedures
116,120
.
3.4.2 Cyclic Voltammetry (CV)
Electrochemistry experiments were carried out using a Pine potentiostat. The experiments
were performed in a single compartment electrochemical cell under nitrogen or CO 2 atmosphere
using a 3 mm diameter glassy carbon electrode as the working electrode, a platinum wire as
auxiliary electrode and a silver wire as the reference electrode. Ohmic drop was compensated using
the positive feedback compensation implemented in the instrument. All experiments in this paper
were referenced relative to ferrocene (Fc) with the Fe
3+/2+
couple at 0.0 V. Alternatively, in cases
when the redox couple of ferrocene overlapped with other redox waves of interested,
decamethylferrocene (Fc*) was as an internal standard with the Fe*
3+/2+
couple at –0.48 V. All
electrochemical experiments were performed with 0.1 M tetrabutylammonium
hexafluorophosphate as supporting electrolyte. The concentrations of the cobalt complexes 1
(II)
–
71
6
(II)
were generally at 0.5 mM and experiments with CO2 were performed at gas saturation or
varying amounts of CO2 in dimethylformamide (DMF).
3.4.3 Controlled-potential electrolysis (CPE)
CPE measurements were conducted in a two-chambered H cell. The first chamber held
the working and reference electrodes in 50 mL of 0.1 M tetrabutylammonium
hexafluorophosphate and 0.5 M methanol in DMF. The second chamber held the auxiliary
electrode in 25 mL of 0.1 M tetrabutylammonium hexafluorophosphate in DMF. The two
chambers were separated by a fine porosity glass frit. The reference electrode was placed in a
separate compartment and connected by a Vycor tip. Glassy carbon plate electrodes (6 cm × 1
cm × 0.3 cm; Tokai Carbon USA) were used as the working and auxiliary electrodes. Using a
gas-tight syringe, 10 mL of gas were withdrawn from the headspace of the H cell and injected
into a gas chromatography instrument (Shimadzu GC-2010-Plus) equipped with a BID detector
and a Restek ShinCarbon ST Micropacked column. Faradaic efficiencies were determined by
diving the measured CO produced by the amount of CO expected based on the charge passed
during the bulk electrolysis experiment. For each species the controlled-potential electrolysis
measurements were performed at least twice, leading to similar behavior. The reported Faradaic
efficiencies and mmol of CO produced are average values.
3.4.4 TOF calculations from cyclic voltammetry
Equations 1–5 were used to determine TOF from catalytic CVs
121
. The catalytic current
(icat) for an EECC process (E = electrochemical, C = chemical step) is given by eq 1, and it
corresponds to the plateau current. This equation assumes a one-electron diffusion current and
pseudo-first-order kinetics (the reaction is first order in catalyst and the concentrations of the
substrates, Q (CO2), is large in comparison to the concentration of catalyst). In eq 1, F is Faraday’s
constant (F = 96 485 C/mol), S is the surface area of the electrode (A = 0.07065 cm
2
for CVs),
𝐶 𝑐𝑎𝑡 0
is the catalyst concentration ([cat] = 0.5 mM = 5 × 10
–7
mol/cm
3
), Dcat is the diffusion constant
of the catalytically-active species (~5 × 10
–6
cm
2
/s), and kcat
is the rate constant of the catalytic
reaction.
72
𝑖 𝑐𝑎𝑡 = 𝐹𝑆 𝐶 𝑐𝑎𝑡 0
√𝐷 𝑐𝑎𝑡 √2𝑘 𝑐𝑎𝑡 (1)
Equation 1 is simplified by standardizing with the current in the absence of substrate (CO2
in this case), as described by eq 2. In eq 2, F is Faraday’s constant (F = 96 485 C/mol), S is the
surface area of the electrode (A = 0.07065 cm
2
for CVs), 𝐶 𝑐𝑎𝑡 0
is the catalyst concentration ([cat]
= 0.5 mM = 5 × 10
–7
mol/cm
3
), Dcat is the diffusion constant of the catalytically-active species (~5
× 10
–6
cm
2
/s), υ is the scan rate (0.1 V/s), R is the universal gas constant (R = 8.31 J K
–1
mol
–1
),
and T is temperature (T = 298.15 K).
𝑖 𝑝 = 0.446 × 𝐹𝑆 𝐶 𝑐𝑎𝑡 0
√𝐷 𝑐𝑎𝑡 √
𝐹𝜐
𝑅𝑇
(2)
Dividing eq 1 by eq 2 allows for determination of icat/ip and allows one to further calculate
the catalytic rate constant (kcat) without having to determine S, 𝐶 𝑐𝑎𝑡 0
, and Dcat. The ratio of equations
1 and 2 produces equation 3 which can be rearranged to produce equation 4 in which kcat can be
solved directly.
𝑖 𝑐𝑎𝑡
𝑖 𝑝 =
1
0.446
× √
2𝑘 𝑐𝑎𝑡
𝜐 𝑅𝑇
𝐹 = 2.24 × √
2𝑘 𝑐𝑎𝑡
𝜐 𝑅𝑇
𝐹 (3)
𝑘 𝑐𝑎𝑡 = (
𝑖 𝑐𝑎𝑡
𝑖 𝑝 )
2
𝜐 2.24
2
𝐹 2𝑅𝑇
(4)
Finally, eq 4 can be simplified into eq 5, from which kcat can be calculated directly.
𝑘 𝑐𝑎𝑡 = 0.387 × (
𝑖 𝑐𝑎𝑡
𝑖 𝑝 )
2
(5)
In the above calculations, the ip values used correspond to the peak current obtained from
the CoI/0 reduction. However, given that the CoI/0 reduction is quasi-reversible, its homogeneity
cannot be tested. Therefore, we have also performed the plateau current analysis using ip values
obtained from the reversible (homogeneous) CoII/I couple and obtained identical results.
3.4.5 TOFCPE calculations from controlled potential electrolysis
73
Equation 6 was used to determine TOF from CPE data, as previously reported
120,121
. This
equation assumes that electron transfer to the catalyst is fast, obeying the Nernst law. In eq 6, i is
the stable current transferred during CPE (i = charge*F.E./time, C/s), F is Faraday’s constant (F =
96 485 C/mol), A is the surface area of the working electrode (A = 3 cm
2
for CPE), kcat is the
overall rate constant of the catalytic reaction, D is the diffusion coefficient (~5 × 10
–6
cm
2
/s), [cat]
is the concentration of the catalyst without substrate ([cat] = 0.5 mM = 5 × 10
–7
mol/cm
3
), R is the
universal gas constant (R = 8.31 J K
–1
mol
–1
), T is temperature (T = 298.15 K), F/RT = 38.92 V
–1
.
When the electrolysis potential is on the plateau of the catalytic wave, the following eq can be used
to calculate TOF, as previously reported
121
.
𝑇𝑂𝐹 = 𝑘 𝑐𝑎𝑡 =
𝑖 2
𝐹 2
𝐴 2
𝐷 [𝑐𝑎𝑡 ]
2
(6)
Controlled potential electrolysis (CPE) experiments, on the other hand, are bulk
experiments that are run for prolonged periods of time and under constant stirring, and therefore,
replenishing of the catalyst in the diffusion layer (at the electrode-liquid interface). In these
experiments, the rate is limited by catalyst, substrate, reagents and products (catalyst, CO2, TFE,
CO) diffusion to and away from the electrode. These experiments provide information about the
stability and selectivity of the catalyst, but do not provide any kinetic information intrinsic to the
catalyst
3
.
74
3.4.6 Synthesis and Characterization
[CoL
2
][BF4]2 (2
(II)
). [Co(MeCN)6][BF4]2 (27.1 mg, 0.070 mmol) in acetone (1 mL) was added to
a of L
2
(16.7 mg, 0.071 mmol) in acetone (2 mL) giving rise to a brown solution. The mixture was
allowed to stir for 5 minutes. The solution was filtered through a microfiber filter. Slow diffusion
with diethyl ether produced orange crystals in quantitative yields.
1
H NMR (400 Hz, MeCN-d3) δ
19.19–18.34 (m, 8H, m-NC5H3), 12.06–11.72 (m, 4H, p-NC5H3), 10.99 (s, 1H, NH), 8.40 (s, 2H,
NH), 2.445 (s, 3H, CMe). Anal. calcd for [Co(L
2
)][BF4]2∙(Et2O)∙(Cl2CH2) ∙(NCCH3)
(C28H33B2Cl2CoF8N9O): C, 41.26 H, 4.96; N, 15.47. Found: C, 41.30; H, 3.53; N, 15.00.
[CoL
3
][BF4]2 (3
(II)
). [Co(MeCN)6][BF4]2 (35.0 mg, 0.088 mmol) in acetone (1 mL) was added to
a solution of L
3
(20.5 mg, 0.088 mmol) in acetone (2 mL) giving rise to a brown solution. The
mixture was allowed to stir for 5 minutes. The solution was filtered through a microfiber filter.
Slow diffusion with diethyl ether produced orange crystals in quantitative yields.
1
H NMR (400
Hz, MeCN-d3) δ 10.80 (s, 2H), 10.33 (s, 2H), 6.57 (s, 4H), 3.56-5.13 (m, 10H), 2.81 (s, 4H). Anal.
calcd for [Co(L
3
)][BF4]2∙(acetone)2∙(H2O)2 (C28H36B2CoF8N8O4): C, 43.05; H, 4.65; N, 14.34.
Found: C, 43.55; H, 4.08; N, 14.28.
[CoL
4
][BF4]2 (4
(II)
). [Co(MeCN)6][BF4]2 (29.4 mg, 0.074 mmol) in acetone (1 mL) was added to
a solution of L
4
(18 mg, 0.077 mmol) in acetone (2 mL) giving rise to a brown solution. The
mixture was allowed to stir for 5 minutes. The solution was filtered through a microfiber filter.
Slow diffusion with diethyl ether produced orange crystals in quantitative yields.
1
H NMR (400
Hz, MeCN-d3) δ 12.92 (s, 2H), 11.21–10.24 (m, 5H), 8.81 (d, 4H), 7.75 (s, 6H), 4.86 (s, 2H). Anal.
calcd for [Co(L
4
)][BF4]2∙(Et2O)∙(H2O)2 (C26H34B2CoF8N8O3): C, 42.25; H, 4.64; N, 15.16. Found:
C, 42.17; H, 4.01; N, 14.75.
[CoL
5
][BF4]2 (5
(II)
). [Co(MeCN)6][BF4]2 (26.6 mg, 0.065 mmol) in acetone (1 mL) was added to
a solution of L
5
(15.2 mg, 0.065 mmol) in acetone (2 mL) giving rise to a brown solution. The
mixture was allowed to stir for 5 minutes. The solution was filtered through a microfiber filter.
Slow diffusion with diethyl ether produced orange crystals in quantitative yields.
1
H NMR (400
Hz, MeCN-d3) δ 12.24 (s, 1H), 10.89 (s, 4H), 9.38 (s, 4H), 8.18 (s, 4H), 3.30 (s, 8H). Anal. calcd
75
for [Co(L5)][BF4]2 (C23H22B2CoF8N8): C, 42.96; H, 3.45; N, 17.43. Found: C, 42.64; H,
3.60; N, 17.53.
Crystal data and structure refinement for 2
(II)
.
Identification code Alon092616
Chemical formula C 25H 24B 2CoF 8N 10
Formula weight 697.09 g/mol
Temperature 100(2) K
Wavelength 0.71073 Å
Crystal size 0.020 0.140 0.180 mm
Crystal habit clear pale orange blade
Crystal system Triclinic
Space group
P1
¯
Unit cell dimensions a = 12.026(6) Å α = 72.461(8)°
b = 12.302(6) Å β = 79.742(8)°
c = 14.145(7) Å γ = 64.354(8)°
Volume 1796.0(15) Å
3
Z 2
Density (calculated) 1.289 g/cm
3
Absorption coefficient 0.549 mm
–1
F(000) 706
Diffractometer Bruker APEX DUO
Radiation source fine-focus tube, MoKα
Theta range for data collection 1.88 to 24.71°
Index ranges –14 ≤ h ≤ 14, –14 ≤ k ≤ 14, –16 ≤ l ≤ 16
Reflections collected 30085
Independent reflections 6104 [R(int) = 0.0928]
Coverage of independent reflections 99.6%
Absorption correction multi-scan
Max. and min. transmission 0.9890 and 0.9080
Structure solution technique direct methods
Structure solution program SHELXTL XT 2014/4 (Bruker AXS, 2014)
Refinement method Full-matrix least-squares on F
2
Refinement program SHELXTL XL 2014/7 (Bruker AXS, 2014)
Function minimized Σ w(F o
2
– F c
2
)
2
Data / restraints / parameters 6104 / 480 / 444
Goodness-of-fit on F
2
1.046
Final R indices 3971 data; I > 2σ(I) R 1 = 0.0868, wR 2 = 0.2252
all data R 1 = 0.1264, wR 2 = 0.2609
Weighting scheme
w =1/[σ
2
(F o
2
)+(0.1322P)
2
+5.3242P]
where P = (F o
2
+2F c
2
)/3
Largest diff. peak and hole 1.038 and –0.678 eÅ
–3
R.M.S. deviation from mean 0.102 eÅ
–3
76
Crystal data and structure refinement for 3
(II)
.
Identification code Alon082916
Chemical formula C 25H 30B 2CoF 8N 8O 3
Formula weight 723.12 g/mol
Temperature 100(2) K
Wavelength 1.54178 Å
Crystal size 0.040 0.070 0.090 mm
Crystal habit clear light orange-brown prism
Crystal system triclinic
Space group
P1
¯
Unit cell dimensions a = 11.1267(14) Å α = 106.688(8)°
b = 11.9052(15) Å β = 101.505(8)°
c = 12.2051(16) Å γ = 100.107(8)°
Volume 1470.1(3) Å
3
Z 2
Density (calculated) 1.634 g/cm
3
Absorption coefficient 5.446 mm
–1
F(000) 738
Diffractometer Bruker APEX DUO
Radiation source IuS microsource, CuKα
Theta range for data collection 3.92 to 68.22°
Index ranges –13 ≤ h ≤ 13, –14 ≤ k ≤ 14, –14 ≤ l ≤ 14
Reflections collected 29257
Independent reflections 5297 [R(int) = 0.1232]
Coverage of independent reflections 98.4%
Absorption correction multi-scan
Max. and min. transmission 0.8120 and 0.6400
Structure solution technique direct methods
Structure solution program
SHELXTL XT 2014/5 (Bruker AXS,
2014)
Refinement method Full-matrix least-squares on F
2
Refinement program
SHELXTL XL 2014/7 (Bruker AXS,
2014)
Function minimized Σ w(F o
2
– F c
2
)
2
Data / restraints / parameters 5297 / 502 / 449
Goodness-of-fit on F
2
1.005
Δ/σ max 0.005
Final R indices 2323 data; I > 2σ(I)
R 1 = 0.0894,
wR 2 = 0.2097
all data
R 1 = 0.2020,
wR 2 = 0.2724
Weighting scheme
w = 1/[σ
2
(F o
2
)+(0.1518P)
2
]
where P = (F o
2
+2F c
2
)/3
Largest diff. peak and hole 1.270 and –1.364 eÅ
–3
R.M.S. deviation from mean 0.172 eÅ
–3
77
Crystal data and structure refinement for 4
(II)
.
Identification code Alon92116
Chemical formula C 24H 23B 2CoF 8N 9
Formula weight 670.06 g/mol
Temperature 100(2) K
Wavelength 0.71073 Å
Crystal size 0.126 0.312 0.495 mm
Crystal habit clear orange prism
Crystal system triclinic
Space group
P1
¯
Unit cell dimensions a = 10.090(5) Å α = 83.756(6)°
b = 11.516(5) Å β = 87.480(6)°
c = 12.743(6) Å γ = 77.894(6)°
Volume 1438.8(11) Å
3
Z 2
Density (calculated) 1.547 g/cm
3
Absorption coefficient 0.681 mm
–1
F(000) 678
Diffractometer Bruker APEX DUO
Radiation source fine-focus tube, MoKα
Theta range for data collection 1.61 to 27.48°
Index ranges –13 ≤ h ≤ 13, –14 ≤ k ≤ 14, –16 ≤ l ≤ 16
Reflections collected 29017
Independent reflections 6601 [R(int) = 0.0286]
Coverage of independent reflections 100.0%
Absorption correction multi-scan
Max. and min. transmission 0.9190 and 0.7290
Structure solution technique direct methods
Structure solution program SHELXTL XT 2014/5 (Bruker AXS, 2014)
Refinement method Full-matrix least-squares on F
2
Refinement program SHELXTL XL 2014/7 (Bruker AXS, 2014)
Function minimized Σ w(F o
2
– F c
2
)
2
Data / restraints / parameters 6601 / 110 / 434
Goodness-of-fit on F
2
1.035
Δ/σ max 0.001
Final R indices 5643 data; I>2σ(I) R 1 = 0.0563, wR 2 = 0.1545
all data R 1 = 0.0664, wR 2 = 0.1636
Weighting scheme
w = 1/[σ
2
(F o
2
)+(0.0887P)
2
+2.8248P]
where P = (F o
2
+2F c
2
)/3
Largest diff. peak and hole 1.442 and –0.613 eÅ
–3
R.M.S. deviation from mean 0.093 eÅ
–3
78
Crystal data and structure refinement for 5
(II)
.
Identification code Alon091216
Chemical formula C 26H 28B 2CoF 8N 8O
Formula weight 701.11 g/mol
Temperature 100(2) K
Wavelength 1.54178 Å
Crystal size 0.040 0.080 0.120 mm
Crystal habit clear light orange prism
Crystal system triclinic
Space group
P1
¯
Unit cell dimensions a = 10.1224(7) Å α = 84.499(5)°
b = 11.5342(8) Å β = 89.722(5)°
c = 12.3686(8) Å γ = 77.529(5)°
Volume 1403.33(17) Å
3
Z 2
Density (calculated) 1.659 g/cm
3
Absorption coefficient 5.631 mm
–1
F(000) 714
Diffractometer Bruker APEX DUO
Radiation source IuS microsource, CuKα
Theta range for data collection 3.59 to 68.32°
Index ranges –12 ≤ h ≤ 12, –13 ≤ k ≤ 13, –14 ≤ l ≤ 14
Reflections collected 31703
Independent reflections 5006 [R(int) = 0.0695]
Coverage of independent reflections 97.3%
Absorption correction multi-scan
Structure solution technique direct methods
Structure solution program SHELXTL XT 2014/4 (Bruker AXS, 2014)
Refinement method Full-matrix least-squares on F
2
Refinement program SHELXL-2014/7 (Sheldrick, 2014)
Function minimized Σ w(F o
2
– F c
2
)
2
Data / restraints / parameters 5006 / 13 / 449
Goodness-of-fit on F
2
1.043
Δ/σ max 0.015
Final R indices 4058 data; I>2σ(I)
R 1 = 0.0698,
wR 2 = 0.1861
all data
R 1 = 0.0858,
wR 2 = 0.1986
Weighting scheme
w = 1/[σ
2
(F o
2
)+(0.1059P)
2
+3.0075P]
where P = (F o
2
+2F c
2
)/3
Largest diff. peak and hole 1.055 and –0.801 eÅ
–3
R.M.S. deviation from mean 0.085 eÅ
–3
79
3.4.7 Additional Electrochemical Data
Figure 3.13. (A) Plot of maximum current density versus the concentration of TFE for complexes
1–6 (0.5 mM) in 0.1 M [nBu4N][PF6] in DMF under CO2 saturation (0.2 M). (B) Plots of the Log
of the rate versus the log of [TFE]. All the slopes are equal to one, indicating a reaction that is first
order in protons.
Figure 3.14. Overlay of current (a) and charge (b) traces for controlled potential electrolysis (CPE)
experiments for complexes 1–6 measured at –2.8 V vs. Fc
+/0
over 2 hours. Electrochemical studies
are performed in DMF solutions containing 0.1 M [nBu4N][PF6] under an atmosphere of CO2 and
in the presence of 2,2,2-trifluoroethanol (1.2 M) (dashed black), and catalyst (0.5 mM each).
80
Figure 3.15. Cyclic voltammograms of 2 (0.5 mM) in a DMF solution containing [nBu4N][PF6]
(0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1 atm) before (blue) and after (green) controlled
potential electrolysis (CPE). After the controlled potential electrolysis, the working electrode was
rinsed (3 × 10 mL DMF) and its electrochemistry was measured in a fresh DMF solution
containing [nBu4N][PF6] (0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1 atm) – red. Scan rate
is 100 mV/s.
Figure 3.16. Cyclic voltammograms of 3 (0.5 mM) in a DMF solution containing [nBu4N][PF6]
(0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1 atm) before (blue) and after (green) controlled
potential electrolysis (CPE). After the controlled potential electrolysis, the working electrode was
rinsed (3 × 10 mL DMF) and its electrochemistry was measured in a fresh DMF solution
containing [nBu4N][PF6] (0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1 atm) – red. Scan rate
is 100 mV/s.
81
Figure 3.17. Cyclic voltammograms of 4 (0.5 mM) in a DMF solution containing [nBu4N][PF6]
(0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1 atm) before (blue) and after (green) controlled
potential electrolysis (CPE). After the controlled potential electrolysis, the working electrode was
rinsed (3 × 10 mL DMF) and its electrochemistry was measured in a fresh DMF solution
containing [nBu4N][PF6] (0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1 atm) – red. Scan rate
is 100 mV/s.
Figure 3.18. Cyclic voltammograms of 5 (0.5 mM) in a DMF solution containing [nBu4N][PF6]
(0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1 atm) before (blue) and after (green) controlled
potential electrolysis (CPE). After the controlled potential electrolysis, the working electrode was
rinsed (3 × 10 mL DMF) and its electrochemistry was measured in a fresh DMF solution
containing [nBu4N][PF6] (0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1 atm) – red. Scan rate
is 100 mV/s.
82
Complex FE (%) Charge (C) Overall TON TOFCPE(s
–1
) TONCPE
1 98 30.9 10 170(20) 1.2(1)×10
6
2 98 32.5 11 190(20) 1.3(1)×10
6
3 98 32.3 10 190(20) 1.3(1)×10
6
4 98 30.0 10 160(20) 1.1(1)×10
6
5 90 32.2 7 155(20) 1.1(1)×10
6
6 36 22.8 2 12.4(1) 9.0(9)×10
3
Table 3.2. Summary of CPE results for complexes 1–6. Overall TON is calculated as
molCO/molcatalyst. TOFCPE (s
–1
) is calculated as described previously, in eq. 6. TONCPE is calculated
by multiplying TOFCPE (s
–1
) with time for CPE studies (2*3600 s).
Figure 3.19. Linear scan voltammograms of 3 (0.5 mM) in a DMF solution containing 0.1
M [nBu4N][PF6] under an atmosphere of CO2 and in the presence of varying concentrations of
TFE. Scan rates are 2000 mV/s.
83
Figure 3.20. Linear scan voltammograms of 4 (0.5 mM) in a DMF solution containing 0.1
M [nBu4N][PF6] under an atmosphere of CO2 and in the presence of varying concentrations of
TFE. Scan rates are 2000 mV/s.
Figure 3.21. Linear scan voltammograms of 5 (0.5 mM) in a DMF solution containing 0.1 M
[nBu4N][PF6] under an atmosphere of CO2 and in the presence of varying concentrations of TFE.
Scan rates are 2000 mV/s.
3.5 Computational Methods
3.5.1 Density functional calculation details
84
Density Functional Theory (DFT) calculations are performed using the Molpro 2015.1
149
and Q-Chem 5.0
150
software packages. Geometry optimizations and frequency calculations
employ Molpro, while implicit solvation calculations use the Q-Chem package (except where
explicitly otherwise mentioned). All Molpro calculations use density fitting of both the Coulomb
and exchange operators with the corresponding JKFIT basis.
151
The B3LYP functional
152-155
is used for all calculations. The more computationally costly
ωB97M-V functional
156
is tested on the CO2 binding energies of complexes 1-6 and gives the same
trend. Q-Chem calculations are done using the relatively-fine Lebedev exchange correlation grid
157
with 75 radial and 302 points. The Molpro grid threshold is set to 10
-10
.
The 6-31+g*
158
basis set is used for all optimizations and frequency calculations. Diffuse
functions are included to properly treat the strong anionic character of the bound CO2 (discussed
in the next section). The larger double zeta basis set def2-SVPD as well as the higher-zeta basis
sets def2-TZVPD and def2-QZVPD
159
are tested, but SCF calculations in these bases do not
converge for every geometry. (All SCF algorithms available in the Q-Chem 5.0 and Molpro 2015.1
packages are tested.)
In a modest basis set such as 6-31+g*, Basis Set Superposition Error (BSSE)
160,161
is a
concern. To correct for BSSE, binding energy calculations are performed using the def2-TZVPD
basis at the 6-31+g* optimized geometry. Binding energy calculations are also attempted using the
def2-QZVPD basis at the 6-31+g* optimized geometry, but all fail except for the single case of
complex 1
(I)
-CO2. For this complex, the difference in binding energy between the quadruple and
triple zeta bases is 0.37 kcal/mol, suggesting that the def2-TZVPD is sufficiently large to eliminate
BSSE. The BSSE associated with the 6-31+g* basis for complex 1
(I)
-CO2 is also evaluated using
the counterpoise method,
162
yielding a correction of 4.4 kcal/mol. This is in excellent agreement
with the BSSE correction derived from the energy difference between the 6-31+g* basis and the
def2-QZVPD basis of 4.2 kcal/mol. BSSE-corrected binding energies are reported in Table 3.3
and main text Figure 3.9.
85
Dimethylformamide solvation energies are computed using the SMD implicit solvent
model
163
in the 6-31+g* basis set using the Q-Chem 5.0 software package. Solvent calculations
are done, as recommended, at the gas phase optimized geometries. The SM12 model
164
is also
tested and yields similar results, but the CM5 charge component of the model does not converge
for all geometries.
When possible, geometry optimizations are started from crystal structure initial guesses,
and the resulting DFT minima do not deviate qualitatively from the crystal structure geometries.
All geometric minima are fully optimized to the default thresholds of the Molpro 2015.1 software
package. Harmonic vibrational calculations verify that all optimized geometries are indeed. These
vibrational calculations also provide finite temperature (300K) harmonic thermodynamic
corrections.
Transition state searches are performed in three steps. First, the freezing string method
165
(15 nodes, 3 gradient descent steps, LST coordinates) is used to estimate a minimum energy path.
Then, the transition state is located using a minimum mode following algorithm from the highest-
energy FSM image.
166
Finally, vibrational calculations are used to verify that transition states are
first-order saddle points.
The geometries of complexes 1
(II)
-6
(II)
and 1
(I)
-6
(I)
are computed in the presence and
absence of explicit solvent molecules in the axial positions. These are found to bind only weakly
(binding energy of 1-2 kcal/mol and bond length of 2.5-3 angstroms) and to not affect the overall
energetics of reduction. Therefore, they are not included in further calculations for the sake of
computational efficiency.
86
Figure 3.22. Top and side views of the optimized geometries of relevant minima for the reaction
mechanism proposed in main text Figure 3 for complex 1. The geometries for intermediates
corresponding to complexes 2-6 are isostructural.
For complexes 1
(II)
-6
(II)
, the experimentally measured quartet spin state of complex 1
(II)
is
used. For complexes 1
(I)
-6
(I)
, the experimentally measured triplet spin state of complex 1
(I)
is used.
For all other complexes, cobalt has 9 d electrons, resulting in a doublet spin state. This assignment
is also tested by computing the energies of the quartet complexes, which are in all cases found to
be significantly higher. Geometries of all structures mentioned in this study are included in the
appendix.
3.5.2 Computed reduction potential of 1
(II)
-6
(II)
The experimentally observed trend in reduction potentials of complexes 1
(II)
-6
(II)
is
explained by two effects: (i) the addition of electron-rich methyl groups is expected to shift
potentials negatively and (ii) alkylation causes a decrease in solubility, shifting potentials
1
(II)
1
(I)
1
(0)
1
(I)
-CO
2
1
(II)
-CO
2
H
1
(II)
-CO
87
positively. To disentangle these effects, DFT calculations – which contain electronic effects but
not solubility effects – are performed.
167
The electronic energies and free energies of solvation for the Co
(II)
and Co
(I)
species are
computed separately, and then subtracted to yield the implicit solvent estimate of the Co
(II)
reduction potential.
168,169
Increasing methylation shifts the reduction toward more negative
potentials. To determine whether this effect is due to increased electron donation by the methyl
substituents, the CHELPG
170
charge of the central cobalt atom is computed. In Figure 3.23, it can
be seen that increasing methyl substitution increases with the charge on cobalt, which in turn shifts
the reduction potential negative.
Figure 3.23. Comparison of computed reduction potential to computed charge on the central cobalt
atom for complexes 1
(II)
-6
(II)
. Reduction potentials are referenced to the ferrocene/ferrocenium
couple as computed using the same DFT model.
3.5.3 Density functional calculations on the binding of CO2
Initial guess geometries for each X
(I)
-CO2 adduct (X=1-6) are generated starting from the
corresponding optimized X
(0)
geometry. The C atom of the ligand is placed at a distance of 2
angstroms from the Co atom of the complex. Binding energies and geometric parameters for
complexes 1
(I)
-CO2 through 6
(I)
-CO2 are given in Table 3.3. Despite a range of 12 kcal/mol in
88
binding energy, the adducts are largely isostructural, with similar C-Co bond lengths and O-C-O
bond angles.
Upon binding, the CO2 ligand bends and assumes the geometry of the gas phase CO2 anion.
In complex 1
(I)
-CO2, the C-O-C angle is 136 degrees (compared to 137 degrees in the gas phase
anion). Similarly, the C-O bond length extends from the gas phase value of 1.17 Å to 1.24 Å to
match that of the gas phase anion. This anionic character is further confirmed by CHELPG atomic
charge analysis. Very similar results are found for complexes 2
(I)
-CO2 through 6
(I)
-CO2 and these
results are summarized in Table 3.3.
Complex Binding energy
(kcal/mol)
C-Co bond
length (Å)
O-C-O angle
(degrees)
C-O bond
length (Å)
CO2
charge
1
(I)
-CO2 -11.8 2.06 135.9 1.24 -0.70
2
(I)
-CO2 -9.9 2.07 135.8 1.24 -0.65
3
(I)
-CO2 -6.1 2.17 141.2 1.22 -0.49
4
(I)
-CO2 -5.3 2.15 140.3 1.22 -0.57
5
(I)
-CO2 +0.3 2.16 140.3 1.22 -0.52
6
(I)
-CO2 -0.4 2.14 139.3 1.23 -0.57
CO2 (g) 180.0 1.17 0
CO2
-
(g) 136.1 1.24 -1
Table 3.3. CO2 binding properties for complexes 1
(I)
-CO2 through 6
(I)
-CO2. Charges were
computed using the CHELPG scheme. Gas phase geometries computed at the same level of
theory are included for comparison.
The C-Co bond length changes by 0.1 Å between complexes 1/2
(I)
-CO2 and 3-6
(I)
-CO2,
suggesting these groups of complexes may correspond to different potential energy minima. To
test this possibility, the CO2 bond lengths in complexes 3-6
(I)
-CO2 were changed to 2.06 Å.
Following optimization from this set of initial guesses, all four complexes relax to their previous
geometry. This suggests that all structures reported in Table 3.3 represent the same qualitative
minimum.
The possibility of intramolecular hydrogen bonding is investigated in complex 1
(I)
-CO2.
The CO2 ligand is rotated 90 degrees and the pendant nitrogen centers were umbrella flipped to
yield guess geometries for either one or two intramolecular hydrogen bonds. Both cases are found
to be unfavorable. Formation of one intramolecular hydrogen bond incurs an energy penalty of 5.2
89
kcal/mol, while formation of two incurs a penalty of 6.5 kcal/mol. The transition states for these
rearrangements are also found. These results are summarized in Figure 3.8.
3.5.4 Embedded multireference calculations on the favorability of hydrogen bonding in
complex 1
(I)
-CO2
The previous section employs DFT to draw conclusions about rearrangements barriers and
hydrogen bond strengths in complexes X
(I)
-CO2 (X=1-5). While DFT has been used to study small
molecule reactions on cobalt complexes and surfaces,
171-180
it can be inconsistent for reaction
barriers in organometallic complexes.
181-185
Further, the geometry and strength of hydrogen bonds
can be strongly functional dependent.
186,187
To verify that DFT is adequate to describe
intramolecular hydrogen bonding and associated rearrangements in complexes 1
(I)
-CO2 accurate
embedded wavefunction-in-DFT calculations on the formation of one hydrogen bond are
performed. (Specifically, the first three structures in Figure 3.8 are considered.)
Projection-based embedding
188,189
calculations are performed in the MOLPRO 2017.0
software package. Calculations are performed in the def2-TZVP basis set. (All other parameters
are the same as those used throughout the text.) B3LYP Kohn-Sham occupied orbitals are localized
by the intrinsic bond orbitals procedure,
190
and the embedded localized orbitals are listed in Table
3.4. These orbitals correspond to the cobalt center, its four bonding nitrogens, the CO2 ligand, and
the hydrogen-bonding amines. The projector weight is set to 10
6
Hartree, which results in B3LYP-
in-B3LYP embedding errors on the order of 0.001 kcal/mol. To reduce the size of the virtual space,
atomic orbital truncation
191
is performed with a charge threshold of 0.001 electrons, resulting in
the retention of 713 of 1102 basis functions. MP2
192
-in-B3LYP calculations confirm reaction
energy convergence with respect to the atomic orbital truncation threshold.
Structure Embedded localized molecular orbitals
1
(I)
-CO2 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14, 15, 24, 37, 38, 39, 40, 41, 42, 45, 46, 47, 48, 49,
50, 51, 52, 53, 54, 59, 61, 62, 67, 68, 69, 70, 79, 80, 93, 94, 95, 96, 99, 100, 101,
102, 103, 104, 105, 114, 115, 116, 117, 118, 119, 120, 121
TS 1 1, 2, 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 24, 37, 38, 39, 40, 41, 42, 45, 46, 47, 48,
49, 50, 51, 52, 53, 54, 56, 61, 62, 67, 68, 72, 76, 79, 80, 93, 94, 95, 96, 99, 100,
101, 102, 103, 104, 105, 114, 115, 116, 117, 118, 119, 120, 121
90
1 H-bond 1, 2, 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 24, 37, 38, 39, 40, 41, 44, 45, 46, 47, 48,
49, 50, 51, 52, 54, 58, 60, 61, 62, 63, 64, 73, 76, 77, 78, 93, 94, 95, 96, 97, 100,
101, 102, 103, 104, 105, 114, 115, 116, 117, 118, 119, 120, 121
Table 3.4. Localized molecular orbital numbers in the embedded subsystem for each geometry
considered. The structure names refer to those of Figure 3.8.
Embedded coupled cluster singles and doubles
193,194
calculations are performed. As
multireference character is always a concern in transition metal complexes, the T1 diagnostic
195
is computed and found to be at least 0.07. This value exceeds both the standard threshold of 0.02
and the threshold of 0.05 suggested for first-row transition metals in Ref.
196
, indicating strong
multireference character.
To treat this multireference character, embedded multireference configuration interaction
singles and doubles (MRCISD)
197,198
are performed with a complete active space self-consistent
field (CASSCF)
199,200
reference. The active space contains nine electrons in nine orbitals. Two
factors suggest this active space is sufficiently large. First, the largest active space (at any
geometry) determined by the unrestricted natural orbtial complete active space method of Bofill
and Pulay
201
is only three electrons in three orbitals. Second, the CAS(9,9) canonical orbital
populations are at most 1.98 for the lowest-energy orbital and at least 0.03 for the highest-energy
orbital across all geometries. Multireference character is confirmed by substantial deviations from
integer occupations within the canonical orbitals.
Embedded calculations increase the energy penalty for the formation of one hydrogen bond
by 1.0 kcal/mol to 6.2 kcal/mol and decrease the associated barrier for this process by 2.8 kcal/mol
to 7.9 kcal/mol. Our qualitative conclusions remain unchanged: formation of intramolecular
hydrogen bonds is thermodynamically unfavorable and CO2 binds without hydrogen bonding.
3.5.5 Structure of the CO2H adduct
After protonation, the CO2H adduct retains the same bonding geometry as the CO2 adduct.
The C-Co bond length does not significantly change for complexes 1
(II)
-CO2H and 2
(II)
-CO2H. In
the remaining four complexes, the C-Co bond contracts by ~0.1 Å, resulting in a tight distribution
of C-Co bond lengths for all six complexes that ranges only over 0.02 Å. The geometric parameters
91
of the CO2H ligand are also nearly identical, resulting in isostructural adducts. This is reflected in
the overall protonation energies of the CO2H adducts, which vary little across the series (main text
Figure 3.10), and in the experimental observation that the overall rate depends only on the number
of pendant amines (main text Figure 3.6). Geometric parameters are presented in Table 3.5.
The CO2H ligand resembles the gas phase anion (Table 3.5), though not as precisely as
does the CO2 ligand (Table 3.3). Focusing on complex 1
(II)
-CO2H, the two C-O bond lengths lie
between the gas phase neutral and anion values. The bond angle of 116 degrees resembles that of
the gas phase anion (112 degrees) more than that of the gas phase neutral molecule (130 degrees).
The CHELPG-computed ligand charge reduces from -0.70 in complex 1
(I)
-CO2 to -0.32 in
complex 1
(II)
-CO2H. Overall, we conclude that the CO2H ligand is less strongly anionic than the
CO2 ligand. This agrees with the computed overall energy of protonation being less favorable in
the CO2 adduct than in the CO2H adduct (main text Figure 3.10).
Complex C-Co bond
length (Å)
O-C-O angle
(degrees)
C=O bond
length (Å)
C-OH bond
length (Å)
CO2H
charge
1
(II)
-CO2H 2.06 116.3 1.22 1.41 -0.32
2
(II)
-CO2H 2.07 116.4 1.22 1.41 -0.27
3
(II)
-CO2H 2.08 116.8 1.23 1.40 -0.22
4
(II)
-CO2H 2.07 116.5 1.23 1.39 -0.30
5
(II)
-CO2H 2.08 116.5 1.23 1.40 -0.32
6
(II)
-CO2H 2.06 117.2 1.22 1.40 -0.27
CO2H (g) 130.1 1.19 1.33 0
CO2H
-
(g) 112.2 1.24 1.45 -1
Table 3.5. Geometric and charge properties of complexes 1
(II)
-CO2H through 6
(II)
-CO2H. Charges
are computed using the CHELPG scheme. Gas phase geometries computed at the same level of
theory are included for comparison.
3.5.6 Mechanism of the second protonation: intra- versus intermolecular proton transfer
As discussed in the main text, a candidate mechanism for the rate-limiting protonation of
the CO2H ligand is intramolecular proton transfer from a pendant amine. This pathway proceeds
in two steps and is illustrated for complex 1
(II)
-CO2H in Figure 3.24. First, the CO2H ligand rotates
roughly 45 degrees toward the pendant amine, which simultaneously undergoes an umbrella flip.
This step is energetically unfavorable by 10.3 kcal/mol and has a barrier of 15.2 kcal/mol. The
second step is proton transfer, which is strongly energetically favorable and incurs an additional
92
barrier of 3.9 kcal/mol. After proton transfer, the C-OH2 bond breaks spontaneously to generate
water.
Figure 3.24. Geometries and energies for intramolecular proton transfer from a pendant amine to
the COOH in complex 1
(II)
-CO2H. This is a candidate mechanism for the rate-limiting protonation
step.
This intramolecular mechanism is not the primary catalytic pathway for two reasons. First,
a lower energy pathway involving acid stabilization is available. Second, this pathway does not
have an explicit acid dependence, contradicting experiment. A possible modification to the
intramolecular mechanism that could allay both concerns comes through acid stabilization of the
transition state. To test this possibility, complex 1
(II)
-CO2H and its intramolecular hydrogen-
bonding intermediate (first and third structures in Figure 3.24) are reoptimized in the presence of
an explicit water molecule – representing the acid – placed near the pendant amine. The explicit
acid molecule raises the energy of the intermediate from 10.3 kcal/mol to 11.4 kcal/mol,
eliminating this explanation. The geometry of the acid-stabilized hydrogen-bonding intermediate
is shown in Figure 3.25.
Figure 3.25. Structure of 1
(II)
-CO2H forming one hydrogen bond between the pendant proton
and the CO2H group in the presence of an explicit acid molecule. For computational efficiency,
water stands in for TFE. Hydrogen bond are indicated by dotted lines labeled by their
corresponding bond lengths in Ångstroms.
1
(II)
-CO
2
H
∆ = 0 kcal/mol
TS 1
∆ = 15.2 kcal/mol
1 H-bond
∆ = 10.3 kcal/mol
TS 2
∆ = 14.2 kcal/mol
1
(II)
-CO + H
2
O
∆ = -8.4 kcal/mol
93
3.5.7 Comparison of the intra- versus intermolecular mechanism for the first protonation
Step First
protonation
Second
protonation
Intramolecular
H-bond formation barrier 10.7 15.2
H-bond formation energy 5.2 10.3
Proton transfer barrier 5.7 3.9
Intermolecular
TFE binding energy -15.6 -4.3
Table 3.6. Comparison of intermediates for intra- and intermolecular protonation between the first
and second protonation steps for complexes 1
(I)
-CO2 (first protonation) and 1
(II)
-CO2H (second
protonation). Energies are listed in kcal/mol and referenced to 1
(I)
-CO2 and 1
(II)
-CO2H in their
corresponding energy minima with no intramolecular hydrogen bonds. These intermediates are
depicted for complex 1
(II)
-CO2H in main text Figure 3.11.
3.5.8 Calculation of proton free energy
In main text Figure 3.10, the thermodynamic driving forces for both protonation steps are
reported. While the arguments made therein rely only on the relative reaction energies between the
first and second protonations and among complexes, it can be helpful to have an absolute energy.
The incomputable (at the DFT level) component of such an energy is the free energy of the proton
in the conditions of the experiment. We thus turn to experimental measurements for a reference.
However, (to our knowledge) there are no measurements of the free energy of the proton in DMF,
but there are measurements in dimethyl sulfoxide, a polar aprotic solvent with a similar dielectric
constant (DMSO=48, DMF=37). Four measurements of the proton free energy in DMSO are
reported and we use the mean of their range, -271.0 kcal/mol.
202
We convert from DMSO to DMF
by computing the difference in protonation energy in these two solvents at the DFT level. This
correction term is small; for example, the correction for the first protonation of complex 1
(I)
-CO2
is 0.5 kcal/mol. These small corrections are corroborated by CV experiments: substitution of DMF
with DMSO in studies of complex 1 did not significantly change the position of the redox waves
or their current densities.
120
94
The proton free energy is then adjusted to account for the presence of 1M 2,2,2-
trifluoroethanol (TFE). Using the pKa of TFE in DMSO (-23.5)
203
and a temperature of 300K, the
effect of the pH is found to be -14.8 kcal/mol.
3.5.9 Acidity of the intermediates
The acidity (pKa) of the intermediates was computed with reference to measured pKas for
complexes X
(II)
, X=1-5. The pKa for general complex Y was computed as:
where kTln(10)=1.364 at room temperature and G represents the computed free energy. The
computed pKas are shown in Table 3.7. Significantly, the pKa of complexes X
(II)
-CO2H (X=1-5)
are consistent with single deprotonation under experimental conditions.
Complex X
(II)
X
(I)
X
(0)
X
(I)
-CO2 X
(II)
-CO2H
1 2.7 9.9 13.0 15.2 2.7
2 2.7 N/A 12.2 15.9 2.5
3 2.5 10.8 10.5 13.2 3.7
4 3.1 11.2 11.2 12.1 3.3
5 2.5 N/A 15.2 12.8 3.5
Table 3.7. pKa for intermediates of the catalytic cycle. Values for complexes X
(II)
(italic) come
from experimental measurements. The remaining values are computed with reference to these
measurements. N/A indicates complexes where calculations failed to converge.
3.6 Analysis of the (E)ECEC mechanism for the second protonation step
3.6.1 Introduction
The mechanism shown in Figure 3 of the main text depicts an EECC sequence, which
involves two reduction steps followed by two chemical proton-transfer steps. As discussed in main
text section “Nature of the rate-limiting protonation”, an alternative (E)ECEC mechanism
(depicted in Figure 3.26) cannot be completely excluded, although DFT calculations suggest the
EECC mechanism is more likely. The conclusions drawn in this work regarding the formation of
95
a CO2-bound pre-association complex and the nature of the rate limiting step are consistent with
both the EECC and (E)ECEC pathways.
Figure 3.26 The alternative (E)ECEC catalytic cycle illustrated with complex 1, where E =
electrochemical, and C = chemical step.
3.6.2 Kinetics of the EECC mechanism
We introduce a mechanism for the kinetics of the catalytic cycle:
N
N N
Co
N N
N
N
N
H
H
H
C
O
O
H
CF
3
O
H
N
N N
Co
N N
N
N
N
H
H
H
C
O
–1
N
N N
Co
N N
N
N
N
H
H
H
N
N N
Co
N N
N
N
N
H
H
H
1e
–
C
O
O
1
(I)
1
(0)
+ H
+
+ TFE
1
(I)
–CO
2
H TFE
TFE + H
2
O
C
O
H
+
1
(I)
–CO
1+
N
N N
Co
N N
N
N
N
H
H
H
1
(II)
1e
–
N
N N
Co
N N
N
N
N
H
H
H
C
O
O
H
CF
3
O
H
1
(II)
–CO
2
H TFE
1e
–
–1
96
(10)
The first step represents potentially reversible CO2 binding to complex X
(0)
(X=1-6). The second
step is the potentially reversible first protonation. The final step is the irreversible second
protonation and regeneration of the catalyst. Based on computational results presented in the
main text sections “Formation of the CO2-bound pre-association complex” and “Nature of the
rate-limiting protonation step”, we assert that the second protonation is rate-limiting, and
therefore k2 is small compared to the other rate constants in this model.
This mechanism leads to the standard set of equations for the concentrations of the
species involved in the reaction:
(11)
In the experiments, the initial concentration of the catalyst is 0.0005 M, which is much
smaller than the initial concentration of CO2 (0.2 M) and TFE (1.2 M). We therefore consider the
behavior of this mechanism over initial observation timescales where the concentration of
reactants do not decrease appreciably:
(12)
In the main text section “Nature of the rate-limiting protonation step,” we compute a
97
strongly energetically downhill (~10 kcal/mol) first protonation reaction energy. We therefore
argue that the first protonation is irreversible:
(13)
Making the steady state approximation for the intermediates X-CO2 and X-CO2H, allows
the rate equations to be solved analytically, yielding the rate law:
(14)
In the limit that CO2 binding is fast compared to the first protonation, this reduces to:
(15)
where KB=kBf/kBb is the equilibrium constant associated with CO2 binding. This final rate law
agrees with the experimentally observed linear dependence of the rate on [CO2] and [TFE] \. It is
also a restatement of the rate law presented in the main text, which expands on the factors that
contribute to k2 and the CO2 binding constant.
To verify that the approximations made in this derivation are reasonable, we also
numerically solve the differential equations without invoking the steady state approximation. We
begin with initial concentrations that reflect those in experiment: [X]i = 0.0005 M, [CO2]i =
0.2M, [TFE]i = 1.2M, and all other initial concentration are zero. We then assign rates consistent
with our mechanism of fast reversible CO2 binding, an irreversible first protonation, and an
irreversible, rate-limiting second protonation: kBf = kBb = 100k2, k1 = 5k2, and k1b = 0.
Time series for the concentrations of intermediates as well as the product CO are shown
in Figure 3.27. The concentrations of catalytic intermediates rapidly reach a constant value,
justifying the steady-state approximation made in the analytics above. After this point,
production of CO is linear in time, as expected for a catalytic process in steady state.
98
Figure 3.27. Time series for the concentrations of intermediates and CO from numerical
simulation.
The dependence of the overall rate on the concentration of CO2 and TFE is also tested
numerically and presented in Figures 3.28 and 3.29. The same rates and initial concentrations as
in the time series simulation are used (with the exception of the varying initial concentration of
CO2 or TFE). The rate is seen to be approximately linear in [CO2] and [TFE]. These trends
become more linear as k1/k2 and kbB/k1 increase.
99
Figure 3.28. Overall rate as a function of CO2 concentration computed numerically with the
kinetic mechanism. Concentrations are chosen to match the experimental values. A linear fit is
shown in gray.
Figure 3.29. Overall rate as a function of TFE concentration computed numerically with the
kinetic mechanism. Concentrations are chosen to match the experimental values. A linear fit is
shown in gray.
These kinetic results (equation 15, and the assumptions that lead to it) are consistent with
the experimental and computational results presented in this study. Specifically, the experimentally
observed linear dependence of the rate on [CO2] and [TFE] in combination with the kinetic model
suggests that: (i) CO2 binding is fast and reversible; (ii) CO2 binding is fast compared to the first
100
protonation; and (iii) the first protonation is irreversible. Point (i) is further supported by the linear
correlation of the computed CO2 binding constant to the overall rate (Figure 3.9). Point (iii) is
further supported by the strongly downhill reaction energy for the first protonation (Figure 3.10).
Taken together, these experimental, computational, and kinetic arguments form a consistent
picture of the proposed CO2 reduction mechanism (summarized in Figure 3.12).
3.6.3 Additional mechanisms captured by the rate model
This kinetic rate model (Equation 10 and 11) is flexible and can produce other rate
dependence on [CO2] and [TFE] that have been seen in other studies of CO2-to-CO reduction.
136
These cases occur if the first protonation is reversible instead of irreversible, or when CO2 binding
is irreversible instead of reversible.
For example, if CO2 binding and the first protonation are reversible and very fast, then
these two steps establish quasi-equilibrium:
(16)
The rate law becomes:
(17)
which is first order in [CO2] and second order in [TFE]. This behavior has previously been seen in
CO2-to-CO reduction in iron porphyrins.
136
If CO2 binding and the first protonation are irreversible and very fast compared to k2, then
all X is rapidly converted to X-CO2H which accumulates, waiting for the second protonation to
occur. Each time the second protonation occurs, the resulting regenerated X is again rapidly
converted to X-CO2H. The result is a saturation of [X-CO2H]:
(18)
and the corresponding rate law:
(19)
which is first order in [TFE] and has no dependence on [CO2].
101
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(98) Bordwell, F. G. Equilibrium acidities in dimethyl sulfoxide solution. Acc. Chem. Res. 2002,
21 (12), 456.
108
CHAPTER 4
Through-Space Charge Effects Modulate the Reduction of Potentials of a Series of Cobalt
Aminopyridine Complexes
109
4.1 Introduction
The conversion of carbon dioxide (CO2) to liquid fuels and other value-added chemicals is
an exciting tactic for mitigating global warming and lowering humanities dependence on fossil
fuels
2,3,6,7
. However, the large thermodynamic barrier associated with the one electron reduction
of CO2 renders it unfeasible
2
. It has been previously shown that this barrier is decreased when CO2
is reduced with multiple equivalents of protons and electrons. This approach suffers from a kinetic
point of view; the difficulty of transferring multiple equivalents of protons and electrons in a
concerted fashion. In nature, difficult reactions are catalyzed by enzymes with uniquely tailored
structural motifs. The enzyme CO-dehydrogenase (CODH) can efficiently and reversibly catalyze
the reduction of CO2 to CO at ambient conditions
37,98,204
. In the enzyme, CO2 is bound by two
metal centers (Fe and Ni) and is also stabilized via hydrogen bond interactions by strategically
placed amino acid residues. Other reaction, such as the Water Splitting Reaction (WSR) is also
catalyzed by a uniquely suited enzyme. WSR occurs at the Oxygen Evolving Complex (OEC) of
photosystem II which consists of a Mn3CaO4 cluster
205-214
. In recent years, it has been shown that
the redox inactive calcium ion has a significant role in tuning the reduction potential of the OEC
through electrostatic interactions
215,216
. These findings and others suggest that the integration of
both hydrogen bond donors and charged redox inactive moieties into molecular catalysts can
facilitate faster turnovers at lower thermodynamic costs
2,215
.
The incorporation of pendant proton relays and hydrogen bond donors into molecular
catalysts has been vastly explored in the context of CO2 reduction
2,55,103,217
. Nickel and cobalt
tetraazamacrocyclic (cyclam) complexes have been shown to catalyze the reduction of CO2 to
CO
55,60,143,218
. Computational studies suggested that CO2 binds to the metal center through the
central carbon and is stabilized by hydrogen bonds to the amines in the ligand framework.
Synthetic and computational studies on a series of mono-, di-, tri-, and tetramethylated cyclam
complexes has shown that activity and selectivity of the catalyst is decreased with subsequent
methylation, indicating that the hydrogen bond stabilization imparted by the amines is crucial for
catalysis
55,60
. Finally, the electrochemical activity of manganese bipyridines and iron porphyrins
has also been shown to increase with the addition of pendant phenols
73,88,94,96,103,136
. Density
functional theory has shown that in the porphyrin example, the phenol groups help stabilize the
reactive Fe
(0)
-CO2 adduct via hydrogen bonds and subsequently enable proton transfer to CO2
88,219
.
110
Redox tuning by incorporation of redox inactive moieties into the second coordination
sphere has been achieved in a broad range of synthetic systems. Changing the identity of the alkali
earth cation in synthetic analogues of the OEC has been shown to dramatically impact the redox
properties of the specie, signifying the importance of electrostatic interactions in the
enzyme
215,216,220,221
. Purely synthetic examples where the metal reduction potentials were tuned
via the incorporation of redox inactive moieties include a series cobalt schiff base complexes with
appended crown functionalities, pyridinediimine iron complexes with pendant-inactive metals in
the second sphere, diboron-anthracenes functionalized with cationic gold, and more
215,216,220,222-
231
. The incorporation of positively charged trimethyl aniliniums (TMA) or negatively charged
sulfates into iron porphyrin systems has been shown to augment both the rate and overpotential of
the systems for CO2 reduction to CO. Structural studies with TMA in different confirmations
around the metal center have shown that TMA’s influence is electrostatic and not electronic in
nature
135
.
Figure 4.1. Schematic depicting the previously reported cobalt amino pyridine macrocycles.
We previously reported a cobalt complex bearing four secondary amines (NH) in the
second coordination sphere that converted CO2 to CO at high turnover rates and faradic efficiencies
(Figure 1). Methylation of all four secondary amines produced an 850-fold reduction in the activity
at indicating that the amines crucial to catalysis. To learn more about the relationship between the
first and second coordination spheres in our system, we synthesized a series of complexes with
different amounts and configurations of secondary amines and methyl groups in the ligand
framework (Figure 4.1). Complexes 1 through 5 were all found to be competent CO2 reduction
catalysts with varying activities at the same overpotential. The absence of a scaling relationship
2+
N
N N
Co
N N
N
N
N
R
4
R
1 R
3
R
2
N
R
2
N N
N N
N
N
N
R
4
R
3
R
1 Co
H CH
3
or R
1–4
=
2+
top view
side view
111
between the second sphere and the overpotential indicated that the amines were not electronically
coupled to the cobalt metal center. A mechanistic study has shown that during catalysis, a single
amine forms a hydrogen bond with an acid molecule, and guides it toward the bound CO 2H
fragment, thus, facilitating proton transfer. Finally, experimental and theoretical pKa
determinations, coupled with literature precedent hinted that in solution the ligands exist in an
anionic form whereupon one amine is deprotonated. While those conclusions fit our model, there
were still questions that remained unanswered. We were interested in elucidating the structure and
electrochemical behavior of the deprotonated species and study the impact that an anion in the
second sphere has on catalysis. In this work, we report the synthesis, characterization, and
electrochemical properties of a series of deprotonated cobalt amino pyridine complexes. We show
that while the amines are not electronically coupled to the metal center, they exert an electrostatic
influence on it, thus, altering its reactivity.
4.2 Results and Discussion
4.2.1 Synthesis of complexes
Complexes 1 through 5 were made according to reported literature procedures. Addition
of excess sodium hydride (NaH) to a solution of complex 1 in pyridine-d5 followed by sonication
gave rise to a color change from amber to deep red. Proton NMR spectroscopy over the course of
an hour showed the disappearance of starting material peaks at 33.39 ppm, 11.20 ppm, and 4.84
ppm, and the appearance of a broad weak resonance at 11.9 ppm (Figure 4.14). Filtration and slow
diffusion with diethyl ether afforded 1’ as red needles in low yields (25%). Single Crystal X-ray
Diffraction (SXRD) experiments on 1’ reveal a cobalt metal center coordinated by the ligand
pyridines in the equatorial position and a single pyridine in the axial position (Figure 4.2).
112
Figure 4.2. (A) Side (left) and top (right) views of the solid-state structure of 1
’
and (B) Side (left)
and top (rght) view overlays of the crystal structures of 1 (black) and 1’ (red) showing the structural
distortions due to deprotonation. The hydrogen atoms on the amines are depicted as spheres for
emphasis.
Complex 1’ bears both deprotonated amines on the same face of the molecule to counter
the cobalt di-cation charge, producing an overall neutral molecule. The N-C bond lengths for the
deprotonated nitrogen atoms are 1.353 Å as compared to their protonated congeners at 1.399 Å.
Both lengths are consistent with a N-C
sp2
single bond and are indicative of a charge that is localize
on the nitrogen atoms. Attempts to reprotonate 1’ with either 2,2,2-Trifluoroethanol (TFE) or
methanol (MeOH) were not successful. These results are consistent with the fact that the pKa of
the amines (2.48) is drastically more acidic than that of TFE (29) and MeOH (35).
113
Figure 4.3. Schematic representation of the deprotonation of cycles 1-4. Reaction conditions (i)
are excess NaH in pyridine over the course of an hour. The spheres represent nitrogen (blue),
hydrogen (pink) and methyl (grey).
Complexes 2’-4’ have been synthesized using an analogous synthetic procedure with the
results summarized in Figure 4.3. The deprotonation of complex 2 proceeds in a similar fashion to
that of complex 1, giving rise to a neutral specie in which both deprotonated amines are on the
same face of the complex. Complexes 3’ and 4’, which have the same amount of secondary and
tertiary amines but in a different configuration, behave differently under identical reaction
conditions. Regardless of the amount of NaH equivalents added or the reaction time, complex 3
gets doubly deprotonated while complex 4 is singly deprotonated. We suspect that the proximity
of the nitrogen atoms in complex 4 makes the formation of a doubly deprotonated specie
unfavorable. The distance between two face sharing amines in 3 and 4 is 5.620 Å, 0.901 Å longer
than the distance between two adjacent amines at 4.719 Å. Given that columbic interactions are
inversely proportional to the distance between them, the preference to keep the charges separated
(i)
N
N N
Co
N N
N
N
N
1' 1'
2+
N
N N
Co
N N
N
N
N
2'
N
N N
Co
N N
N
N
N
H
3
C
H
3
C H
CH
3
N
CH
3
N N
N N
N
N
N
H
3
C
CH
3
Co
3+
5'
2+
(i)
1
2' 2
N
N N
Co
N N
N
N
N
3'
2+
(i)
3' 3
N
N N
Co
N N
N
N
N
CH
3
4'
2+
(i)
4' 4
+
H
+
2+
(i)
5
H
H
5'
3+
H
3
C
H
H
3
C
H
3
C
CH
3
114
is consistent with them being on the nitrogen atoms and not delocalized through the ligand. Finally,
like 1 and 1’, overlays of 2’-4’ with their parent complexes show minimal structural distortion
(Figure 4.4), indicative of little to no delocalization of charge throughout the molecule.
Figure 4.4. Side (left) and top (right) view overlays of the crystal structures of 2-3 (black) and 2’-
3’ (colored) (A through C) showing the structural distortions due to deprotonation. The hydrogen
atoms on the amines are depicted as spheres for emphasis.
Treatment of a pyridine solution of 5 with excess NaH and sonication gave rise to a color
change like the one observed for complexes 1-4 (Figure 4.5, top). However, SXRD analysis of
115
crystals grown from a pyridine ether vapor diffusion reveals that 5’ crystallizes as a 1:1 mixture of
protonated and deprotonated cycles held together by a hydrogen bond between the protonated and
deprotonated amines of the respective molecules (Figure 4.5, bottom). This result is surprising
given the fact that the pKa of the secondary amine is so acidic, suggesting that hydrogen bond
stabilization plays a major role in formation of 5’. The proton NMR of 5’ does not feature any
resonances that can be attributed to the parent 5, even at high or low temperatures (Figure 4.6)
Figure 4.5. (top) Schematic representation of the deprotonation of 5. Reaction conditions (i) are
excess NaH in pyridine over the course of an hour. The spheres represent nitrogen (blue), hydrogen
(pink) and methyl (grey). And (bottom) solid-state crystal structure of 5’ showcasing the hydrogen
bond between the two cycles.
116
Figure 4.6.
1
H NMR spectra of 5’ at different temperatures in py-d5. Note that the spectrum of 5’
does not resolve as 5 at any temperature.
Figure 4.7. Chemdraw schematic for the synthesis of 5-K (top) and the solid-state crystal structure
of 5-K.
117
Finally, attempts to further deprotonate complexes 1-5 with more than one equivalent of
potassium tert-butoxide (KOtBu) or sodium hexamethyldisilyl (NaHMDS) gave rise to a blue or
green solution, respectively, and the appearance of sharp multiplets in the diamagnetic region.
Crystals grown from the reaction of 5 and KOtBu out of a toluene ether mixture reveal a dimerized
ligand salt 5-K (Figure 4.7). We suspect that the formation of metal alkoxides or amides
(depending on the base used) serves as a driving force for this decomposition pathway.
4.2.2 Electrochemical characterization of 1’ and 5’
A typical electrochemical experiment was performed in a DMF solution containing 0.5
mM of metal complex, 0.1 M [nBu4N][PF6] as a supporting electrolyte, and either ferrocene (Fc)
or decamethylferrocene (Fc*) as an internal reference. All potentials were referenced to the Fc
+/0
couple. Cyclic voltamograms of 1’ under an atmosphere of N2 reveal a reversible feature at -1.99
V assignable to the Co
2/1
couple. A quasi-reversible reduction event was observed at -3.24 V with
a return oxidation at -2.65 V was assigned to the Co
1/0
(Figure 4.8). The negative shift in potential
for both couples is expected due to the electrostatic influence of both negatively charged amines
in the second coordination sphere. Performing the same experiment under CO2 produces a small
wave with a maximum at -2.75 V, which is attributed to CO2 reduction. Finally, titration with TFE
gives rise to reactivity and rates like those of 1 (Figure 4.9)
Figure 4.8. Cyclic voltammograms of 1’ going to different potentials in DMF solution containing
0.1 M [nBu4N][PF6] under an atmosphere of N2 displaying the reversible (black) and quasi-
reversible (red) Co
2/1
and Co
1/0
couples, respectively. All potentials are referenced versus Fc
+
/Fc
118
Figure 4.9. (A) Linear scan voltammograms of 1’ (0.5 mM) in a DMF solution containing 0.1 M
[nBu4N][PF6] under an atmosphere of CO2 and in the presence of varying concentrations of TFE.
And (B) plot of the observed rate constants kobs vs. [TFE] for complexes 1 and 1’ (0.5 mM) in a
DMF solution containing 0.1 M [nBu4N][PF6], and CO2 (0.2 M) at 100 mV/s. The slopes are
11,708 and 11,287 M
–1
s
–1
for 1 and 1’, respectively.
We next wanted to determine if the shift in potential is proportional to the charge on the
cycle. While attempts to make a mono deprotonated version of complex 1 proved unfruitful, we
hypothesized that in an equimolar solution, 1 and 1’ would exchange to generate the mono
deprotonated intermediate in situ. Cyclic voltammetry experiments on a mixture of 1 and 1’ show
a single, reversible event at -1.75 V and a quasi-reversible event at -3.00 V (return oxidation at -
2.30 V), assignable to the Co
2/1
and Co
1/0
couples, respectively (Figure 4.10). The position of the
features, between those of 1 and 1’ indicates that the redox potentials of the Co
2/1
and Co
1/0
couples
are indeed dependent on the amount of charge on the cycle. Finally, 0.2 M TFE can be used to
regenerate the parent complex as indicated by cyclic voltammetry. Also, of note is the shape of the
Co
1/0
couple (Figure 4.10B). For complex 1’, the Co
1/0
feature behaves as a well-defined, quasi-
reversible couple. As protons are added, the couple shifts positively, and its well-defined S shape
is lost. This behavior is consistent with a reaction between the reduced cobalt specie and protons
(such as the formation of a cobalt hydride) and can be used to explain the ambiguous nature of the
couple.
119
Figure 4.10. Cyclic voltammograms of 1’ (0.5 mM), 1’+1 (1 mM total), and 1’+1 (1 mM total) +
0.2 M TFE in a DMF solution containing 0.1 M [nBu4N][PF6] under an atmosphere of N2
displaying a positive shift in the (A) reversible one-electron reduction of the Co
2/1
couple from E1/2
of –1.99 V to -1.74 V to -1.68 V and quasireversible one electron couple -3.24 V to -3.00 V to -
2.58 V. All potentials are referenced versus Fc
+
/Fc
Finally, we performed the same analysis on 5’, which boasts the advantage of being a well-
defined mixture of complex 5 and its deprotonated congener. Scanning to moderately negative
potentials, we observe a reversible couple at -1.64 V which we assigned to the Co
2/1
couple. Upon
scanning to more negative potentials we observe an irreversible feature at -2.98 V which is
attributed to the Co
1/0
couple (Figure 4.11). Both features are shifted negatively compared to those
of the parent complex 5 at -1.44 V and -2.87 V, respectively (Figure 4.12). This behavior is
analogous to that of 1’. It is interesting to note that even though 5’ is a mixture of two different
isomers it behaves as a single species, suggesting that in solution, the cycles exist in a dynamic
equilibrium. Finally, titration of 5’ with TFE gives rise to activity identical to that of 5 (Figure
4.13).
120
Figure 4.11. Cyclic voltammogram of 0.5 mM of 5’ in a DMF solution containing 0.1 M
[nBu4N][PF6] under an atmosphere of N2 (black and blue) or CO2 (red). Scan rate is 100 mV/s.
Figure 4.12. Cyclic voltammogram of 0.5 mM of 5 (red) and 5’ (blue) in a DMF solution
containing 0.1 M [nBu4N][PF6] under an atmosphere of (A) N2 and (B) CO2, showing the negative
shift which occurs upon deprotonation. Scan rates are 100 mV/s.
Figure 4.13. (A) Linear scan voltammograms of 5’ (0.5 mM) in a DMF solution containing 0.1 M
[nBu4N][PF6] under an atmosphere of CO2 and in the presence of varying concentrations of TFE.
121
Scan rates are 100 mV/s. And (B) Plot of the observed rate constants kobs vs. [TFE] for complexes
5 and 5’’ (0.5 mM) in a DMF solution containing 0.1 M [nBu4N][PF6], and CO2 (0.2 M) at 100
mV/s. The slopes are 20.0 and 55 M
–1
s
–1
for 5 and 5’, respectively
4.3 Conclusion
We synthesized and characterized a series of cobalt aminopyridine complexes with
charges in the secondary coordination sphere. Structural studies show that deprotonation is
driven by the formation of a neutral specie, charge separation within the complex, and
intermolecular hydrogen bond stabilization. Electrochemical studies show that an anionic charge
in the second sphere exerts an electrostatic influence on the cobalt metal center, shifting the Co
2/1
and Co
1/0
reduction potentials more up to 600 mV more negatively. Studies of complexes with
different levels of deprotonation show that the cathodic shift of the redox couples is dependent
on the amount of charge in the second coordination sphere. We have also shown that the ill-
defined nature of the Co
1/0
couple is due to a reaction between the reduced cobalt specie and
adventitious protons. The results reported in this work demonstrate the feasibility of using
electrostatic interactions to tune the redox properties of organometallic catalysts. We are
currently investigating the reactivity of these new zwitterionic complexes in the context of CO2
reduction and beyond.
122
4.4 Experimental Details and Additional Figures.
4.4.1 General
All manipulations of air and moisture sensitive materials were conducted under a nitrogen
atmosphere in a Vacuum Atmospheres drybox or on a dual manifold Schlenk line. The glassware
was oven-dried prior to use. All solvents were degassed with nitrogen and passed through activated
alumina columns and stored over 4Å Linde-type molecular sieves. Deuterated solvents were dried
over 4Å Linde-type molecular sieves prior to use. Proton NMR spectra were acquired at room
temperature using Varian (Mercury 400 2-Channel, VNMRS-500 2-Channel, VNMRS- 600 3-
Channel, and 400-MR 2-Channel) spectrometers and referenced to the residual 1 H resonances of
the deuterated solvent (
1
H: CDCl3, δ 7.26; C6D6, δ 7.16; CD2Cl2, δ 5.32; CD3CN, δ 2.94) and are
reported as parts per million relative to tetramethylsilane. Elemental analyses were performed
using Thermo Scientific™ FLASH 2000 CHNS/O Analyzers. All the chemical reagents were
purchased from commercial vendors and used without further purification. The ligands L
1–2
were
prepared according to the reported literature procedures.
4.4.2 Cyclic Voltammetry (CV)
Electrochemistry experiments were carried out using a Pine potentiostat. The experiments
were performed in a single compartment electrochemical cell under nitrogen or CO2 atmosphere
using a 3 mm diameter glassy carbon electrode as the working electrode, a platinum wire as
auxiliary electrode and a silver wire as the reference electrode. Ohmic drop was compensated using
the positive feedback compensation implemented in the instrument. All experiments in this paper
were referenced relative to ferrocene (Fc) with the Fe
3+/2+
couple at 0.0 V. Alternatively, in cases
when the redox couple of ferrocene overlapped with other redox waves of interested,
decamethylferrocene (Fc*) was as an internal standard with the Fe*
3+/2+
couple at –0.48 V. All
electrochemical experiments were performed with 0.1 M tetrabutylammonium
hexafluorophosphate as supporting electrolyte. The concentrations of the cobalt complexes 1’–5’
were generally at 0.5 mM and experiments with CO2 were performed at gas saturation or varying
amounts of CO2 in dimethylformamide (DMF).
123
4.4.3 TOF calculations from cyclic voltammetry
Equations 1–5 were used to determine TOF from catalytic CVs
121
. The peak catalytic
current (icat) for an EECC process (E = electrochemical, C = chemical step) is given by eq 1, and
it corresponds to the plateau current. This equation assumes a one-electron diffusion current and
pseudo-first-order kinetics (the reaction is first order in catalyst and the concentrations of the
substrates, Q (CO2), is large in comparison to the concentration of catalyst). In eq 1, F is Faraday’s
constant (F = 96 485 C/mol), S is the surface area of the electrode (A = 0.07065 cm
2
for CVs),
𝐶 𝑐𝑎𝑡 0
is the catalyst concentration ([cat] = 0.5 mM = 5 × 10
–7
mol/cm
3
), Dcat is the diffusion constant
of the catalytically-active species (~5 × 10
–6
cm
2
/s), and kcat
is the rate constant of the catalytic
reaction.
𝑖 𝑐𝑎𝑡 = 𝐹𝑆 𝐶 𝑐𝑎𝑡 0
√𝐷 𝑐𝑎𝑡 √2𝑘 𝑐𝑎𝑡 (1)
Equation 1 is simplified by standardizing with the current in the absence of substrate (CO2
in this case), as described by eq 2. In eq 2, F is Faraday’s constant (F = 96 485 C/mol), S is the
surface area of the electrode (A = 0.07065 cm
2
for CVs), 𝐶 𝑐𝑎𝑡 0
is the catalyst concentration ([cat]
= 0.5 mM = 5 × 10
–7
mol/cm
3
), Dcat is the diffusion constant of the catalytically-active species (~5
× 10
–6
cm
2
/s), υ is the scan rate (0.1 V/s), R is the universal gas constant (R = 8.31 J K
–1
mol
–1
),
and T is temperature (T = 298.15 K).
𝑖 𝑝 = 0.446 × 𝐹𝑆 𝐶 𝑐𝑎𝑡 0
√𝐷 𝑐𝑎𝑡 √
𝐹𝜐
𝑅𝑇
(2)
Dividing eq 1 by eq 2 allows for determination of icat/ip and allows one to further calculate
the catalytic rate constant (kcat) without having to determine S, 𝐶 𝑐𝑎𝑡 0
, and Dcat. The ratio of equations
1 and 2 produces equation 3 which can be rearranged to produce equation 4 in which kcat can be
solved directly.
𝑖 𝑐𝑎𝑡
𝑖 𝑝 =
1
0.446
× √
2𝑘 𝑐𝑎𝑡
𝜐 𝑅𝑇
𝐹 = 2.24 × √
2𝑘 𝑐𝑎𝑡
𝜐 𝑅𝑇
𝐹 (3)
𝑘 𝑐𝑎𝑡 = (
𝑖 𝑐𝑎𝑡
𝑖 𝑝 )
2
𝜐 2.24
2
𝐹 2𝑅𝑇
(4)
124
Finally, eq 4 can be simplified into eq 5, from which kcat can be calculated directly.
𝑘 𝑐𝑎𝑡 = 0.387 × (
𝑖 𝑐𝑎𝑡
𝑖 𝑝 )
2
(5)
4.4.4 General procedure for the synthesis of 1’-5’
The starting metal complex (ca. 15 mg) was dissolved in pyridine-d 5 in an air and moisture free glovebox.
Excess amount of sodium hydride (~5eq per amine) was added to the metal complex solution and the
suspension was transferred to a J-young tube and sealed. The J-young tube was sonicated (ca. 1 hr). The
reaction was monitored by NMR to ensure its completion. Once done, the reaction mixture was brought
back into the box, filtered, and diffused with diethyl either overnight to produce the product as a crystalline
solid.
Complex 1’. 25% yield. (500 MHz, Py-d 5): δ 11.9 (s, 14H) Anal. calcd for [Co(L
1
)][BF 4]∙(Py) 2∙(Et 2O)
(C 34H 34CoN 10O): C, 62.10 H, 5.21; N, 21.3. Found: C, 61.90; H, 4.16; N, 20.76.
Complex 2’. 30% yield. (500 MHz, Py-d 5): δ 9.5 (s), 6.0 (s), 4.3 (s), 2.5 (s). Anal. calcd for [Co(L
2
)]∙(Py) 2
(C 31H 26CoN 10): C, 62.30 H, 4.39; N, 23.44. Found: C, 62.65; H, 4.29; N, 23.86.
Complex 3’. 22% yield. (500 MHz, Py-d 5): δ 9.5 (s), 5.3 (s), 3.7 (s), 2.9 (s), 2.0-0.3 (m). Anal. calcd for
[Co(L
3
)]∙(Py) 3 (C 37H 33CoN 11): C, 64.34; H, 4.82; N, 22.31. Found: C, 64.87; H, 3.96; N, 10.05.
Complex 4’. 25% yield. (500 MHz, Py-d 5) : δ 20.2 (s), 18.1-16.0 (8), 10.5 (s), 9.8 (s), 1.9-0.3 (m). Anal.
calcd for [Co(L
4
)][BF 4] 2∙(Py) 2∙(Et 2O)∙Na (C 36H 39B 2CoF 8N 10NaO): C, 50.03; H, 4.55; N, 16.21. Found: C,
49.14; H, 4.31; N, 16.05.
Complex 5’. 65% yield. (500 MHz, Py-d 5): δ 11.8 (s, 4H), 9.5-9.0 (m, 8H), 7.8 (s, 6H), 2.3 (s, 6H), 1.5-
0.3 (m, 18H). Anal. calcd for [Co(L
5
)] 2[BF 4] 4∙(Et 2O) 2∙Na (C 54H 62B 4Co 2F 16N 16NaO 2): C, 44.57; H, 4.29; N,
15.40. Found: C, 44.02; H, 3.86; N, 15.14.
4.4.5 Independent synthesis of 5-K
Ligand L
5
(8.0 mg, 0.0195 mmol) was dissolved in a stir bar equipped schlenk flask with toluene
(2 mL) in a moisture and oxygen free glovebox. Potassium Hydride (KH, 4 mg, 0.1 mmol) was added to
the toluene mixture. The flask was sealed, taken out of the glove box, and sonicated (ca. 1 hr). Upon reaction
completion the schlenk flask was brought back into the glove box and its contents were filtered to remove
excess KH. The solution was slowly diffused with diethyl ether over the course of 2 days to produce 5-K
as yellow crystals (85% yield)
1
H NMR (600 MHz, Py-d 5) δ7.41 (t, 2H, p-py), 7.25 (t, 2H, p-py), 6.68 (d,
2H, m-py), 6.42 (d, 2H, m-py), 6.35 (d, 2H, m-py), 5.92 (d, 2H, m-py), 3.12 (s, 3H, CH 3), 3.00 (s, 6H, CH 3).
13C
2
NMR (126 MHz, Py-d 5) δ167.02 161.26, 160.12, 159.15, 141.07, 138.59, 39.32, 38.84.
125
4.4.6 Additional Figures
Figure 4.14.
1
H NMR spectrum of 1 (top) and 1’ (bottom). Starting material peaks are labeled with red
circles while product peaks are labeled with blue circles. The unlabeled peaks correspond to pyridine-d 5,
residual organic solvents, and grease.
Figure 4.15.
1
H NMR spectrum of 2 (top) and 2’ (bottom). Starting material peaks are labeled with red
circles while product peaks are labeled with blue circles. The unlabeled peaks correspond to pyridine-d 5,
residual organic solvents, and grease.
126
Figure 4.16.
1
H NMR spectrum of 3 (top) and 3’ (bottom). Starting material peaks are labeled with red
circles while product peaks are labeled with blue circles. The unlabeled peaks correspond to pyridine-d 5,
residual organic solvents, and grease.
Figure 4.17.
1
H NMR spectrum of 4 (top) and 4’ (bottom). Starting material peaks are labeled with red
circles while product peaks are labeled with blue circles. The unlabeled peaks correspond to pyridine-d 5,
residual organic solvents, and grease.
127
Figure 4.18.
1
H NMR spectrum of 5 (top) and 5’ (bottom). Starting material peaks are labeled with red
circles while product peaks are labeled with blue circles. The unlabeled peaks correspond to pyridine-d 5,
residual organic solvents, and grease.
Figure 4.19. Side (left) and top (right) views of the solid-state structure of 2
’
. Hydrogen atoms, non-
coordinating anions, and solvent molecules are omitted for clarity.
Figure 4.20. Side (left) and top (right) views of the solid-state structure of 3’. Hydrogen atoms, non-
coordinating anions, and solvent molecules are omitted for clarity.
128
Figure 4.21. Side (left) and top (right) views of the solid-state structure of 4’. Hydrogen atoms, non-
coordinating anions, and solvent molecules are omitted for clarity.
129
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132
CHAPTER 5
Para Substitution in Cobalt Aminopyridine Catalyst Impacts the Proton Affinity of a Bound CO2
Ligand
133
5.1 Introduction
With carbon dioxide (CO2) levels increasing in the atmosphere, there has been an ever-
growing interest in addressing its negative environmental repercussions
1-4
. In nature, CO2 is
converted rapidly and reversibly to carbon monoxide (CO) by the enzyme CO-dehydrogenase
(CODH)
2,5,6
. The enzymatic reduction mechanism involves the activation of CO2 by the two metal
centers in the NiFe cluster and further stabilization via hydrogen bonding from strategically placed
amino acid residues. Structural studies have also shown that electron transfer within the enzyme
is made facile due to the presence of an iron sulfur cluster in the active site. It is thought that the
redox active cluster can store and shuttle multiple equivalents of electrons into the active site
allowing for rapid CO2 reduction or CO oxidation
2
.
Other metalloenzymes also perform difficult multi-electron transformations at ambient
conditions by taking advantage of appropriately tuned electronic environments. The iron-iron
hydrogenase active site, for example, features a bimetallic motif with an adjacent pendant nitrogen
that can reduce protons to dihydrogen (H2)
2
. In the first coordination sphere, the iron atoms are
stabilized by carbon monoxide and cyanide molecules
7,8
. These ligands bind to low valent metals
and form low spin complexes which are known to interact with hydrogen to form hydride
intermediates
9
. Furthermore, due to the ability of the enzyme to both reduce protons and oxidize
H2, the hydride acceptor ability of the iron must match that of the neighboring bases to afford a
zero-net energy for H2 addition or release
10,11
. Thus, the first coordination environment dictates
both the reactivity of the iron center, but also the reactivity of the bound substrate. Other enzymes
with specially tailored electronic environments include, among others, nitrogenase that can
catalyze the reduction of dinitrogen to ammonia, copper amine oxidase which can transform
primary amines to aldehydes, galactose oxidase which oxidizes primary alcohols to aldehydes, and
more. These findings and others suggest that the integration of electron reservoirs and redox active
moieties into molecular catalysts can enable catalysis by facilitating electron transfer with greater
ease.
The electronic augmentation of molecular CO2 reduction catalysts has shown premise for
catalyst improvement. The modification of bipyridine ligands in the 4 and 4’ positions has given
rise to significant changes in the overall rates and overpotentials
12,13
. Electron withdrawing and
donating substituents were observed to impact the potential required for catalysis (overpotential)
134
and the reaction rate (Kobs). Using a combined theoretical and experimental approach, it was shown
that ligand substitutions impact both the affinity of the reduced complex to bind CO2, but also the
overall ability of the CO2 adduct to get protonated
12,13
. Iron porphyrins are another family of well-
studied metal complexes capable of converting CO2-to-CO catalytically. It has been shown that
increasing substitution with electron withdrawing pentafluorobenzene groups (C6F5) around the
ligand framework has contributed to a decrease in both overpotential and activity
14,15
. The opposite
phenomenon was observed when the porphyrin was substituted with electron donating dimethoxy
groups (C6H3OMe2). The rationale behind this behavior was that the additional electron density on
the metal makes reduction more difficult (larger overpotential) while boosting the charge on the
CO2 adduct, making protonation and reduction more facile (faster rates)
14
. This phenomenon is an
example of a scaling relationship in which there is a compromise between the rate and the
overpotential
16-18
. Significant work has been done to understand the dynamics behind the above
tradeoff and synthesize catalysts in which both parameters are optimized
14,19,20
.
We previously reported a cobalt complex (1) bearing four pendant secondary amine (NH)
groups incorporated in the ligand scaffold that is an efficient electrocatalyst for the selective
reduction of CO2 to CO
21
. Through a synthetic, electrochemical, and computational study, we have
shown that the amines can facilitate proton transfer to the protonated CO 2 ligand by hydrogen
bonding to and aligning an acid molecule in the proper orientation for proton transfer. We have
also shown that rate of catalysis increases with the number of secondary amines, with no change
in reduction potential. These conclusions indicate that the second coordination sphere and the
overpotential do not scale together
21
. While our findings have shown that hydrogen bonding
moieties in the second sphere can help facilitate proton transfer from an acid molecule to a bound
CO2 ligand, we were interested in tuning the ligand to affect the ability of the complex to trap CO 2
and protonate it. In this current work, we synthesize and investigate a series of cobalt
aminopyridine compounds bearing electron donating and withdrawing groups in the para-
positions of the ligand pyridines. We combine experimental and computational approaches to
understand the effects that these electronic modifications have on the propensity of CO2 to bind to
the metal complex and on the nucleophilicity of the bound CO2 and CO2H ligands.
135
Figure 5.1. Chemdraw schematic of the complexes presented in this work
5.2 Results and Discussion
5.2.1 Ligand Synthesis
Since the methodology for the synthesis of the un-substituted parent complex has been
previously reported, it served as a starting point for our modified synthesis
22
. Ligand
CF3
L where
all four pyridines contain a CF3 group was synthesized first. (Figure 5.2). Beginning with 2,6-
dichloro-4-(trifluromethyl)pyridine (A), we attempted to convert the chloride atoms to allylamine
functional groups. Due to the electron deficient nature of this starting material we only obtained a
mono substituted derivative with traces of the desired di-substituted configuration. We found that
increasing both the temperature from 80 °C to 135 °C, and the reaction time from 24 hr to 72 hr
has produced the desired product in 50% yield as a white solid (B). Deprotonation of B with
sodium hydride (NaH) in refluxing THF, followed by addition of an excess of A led to the
formation of the linear trimer (C) as a yellow solid in 80% yield. A palladium catalyzed Buchwald-
Hartwig coupling using tris-dibenzyl dipalladium (Pd2DBA3), 1,1’-Ferrocenediyl-
bis(diphenylphosphine) (DPPF), and sodium tert-butoxide (NaO
t
Bu) between B and C was used
to make the allyl protected cycle (D) as a yellow solid in 20% yield. Reflux of D in toluene in the
presence of Pd2DBA3, DPPF and excess potassium tert-butoxide (KO
t
Bu) afforded a cycle bearing
isomerized allyls which were cleaved with during an acidic workup to produce
CF3
L as a brown
solid in 70% yield.
136
We next attempted to make the electron rich variant of the ligand using the same approach
(Figure 5.3). 2,6-dichloro-4-(dimethylamine)pyridine (E) was synthesized according to literature
procedure. Unfortunately, Ullman coupling between E and allylamine only produced the mono
substituted 2-chloro-4(dimethylamine)-6-allylamino-pyridine in low yields even at high
temperatures and long durations. A Buchwald-Hartwig coupling between E and allylamine did
produce the desired substituted pyridine (F) albeit in relatively low yields (~30%). F is an air
sensitive orange solid, necessitating its storage under an inert atmosphere. Condensation of F with
an excess of E in refluxing THF and in the presence of NaH was unsuccessful due to the poor
electrophilic nature of E. Performing the reaction under other conditions (e.g. different
temperatures, solvents, bases, coupling reagents) also failed to produce the desired linear trimer at
reasonable yields and reproducibility. Finally, we decided to perform a condensation between F
and 2,6-dibromopyridine reasoning that the better electropilic nature of the latter will allow a
reaction. Deprotonation of F in refluxing THF with NaH and subsequent addition of 2,6-
dibromopyridine gave rise to linear trimer G in 65% yield. Compound G is amber oil like F,
however, it is stable in air and can be stored on the bench for prolonged periods of time. The
coupling between G and F proceeded smoothly under the previously reported conditions to afford
cycle H as an off-white solid. The allyl groups on H were found to isomerize spontaneously during
the cyclization process. Subsequently, deprotection consisted of an acidic workup to produce the
new ligand
NMe
L as a brown solid in 65% yield.
137
Figure 5.2. Synthetic scheme for the preparation of
CF3
L. (I) A, Allylamine, CuBr, L-Proline,
K2CO3, 10:1 DMSO:H2O, 135 °C, 72 h, 50 % (II) NaH, THF, 80 °C, A, 2 h, 80 % (III) B, C,
Pd2DBA3, DPPF, NaO
t
Bu, Tol, 110 °C, 1 h, 20% (IV) Pd2DBA3, DPPF, KO
t
Bu, Tol, 110 °C, 12
h, 70%
138
Figure 5.3. Synthetic scheme for the preparation of NMe2L and MixL. (I) Allylamine,
Pd2DBA3, DPPP, NaOtBu, Tol, 110 °C, 12 h, 30 % (II) NaH, THF, 80 °C, 2,6-Dibromopyridine,
2 h, 65 % (III) F, G, Pd2DBA3, DPPP, NaO
t
Bu, Tol, 110 °C, 1 h, (IV) HCl, 10:1 DMSO:H2O, 60
°C, 1 h, 35 %
139
Figure 5.4. (I) NaH, THF, 80C, A, 2 h, 70 % (II), I, F, Pd2DBA3, DPPP, NaO
t
Bu, Tol, 110 C, 1
h, 25% (III) Pd2DBA3, DPPF, KOtBu, Tol, 110 C, 12 h, 85 %
Having produced the appropriate fragments, we decided to make a third ligand bearing
both NMe2 and CF3 groups on the pyridines. We were particularly interested in this ligand as this
would be the first example of a CO2 reduction electrocatalyst bearing both electron donating and
withdrawing groups. Deprotonation of F in THF with NaH followed by the addition of excess A
produced the linear trimer I as a yellow solid in 70% yield. Coupling of fragments F and I
according to literature procedures produces the new mixed cycle J as a sticky yellow solid in 25%
yields. Finally, deprotection using Pd2DBA3, DPPF and excess potassium tert-butoxide (KOtBu)
afforded produced the ligand,
Mix
L as a brown solid in 85% % yield.
5.2.2 Metalation and physical characterization.
Addition of the
CF3
L to a solution of [Co(BF4)2(H2O)6] in acetonitrile and slow diffusion
with diethyl ether produced x-ray quality crystals of 2 (Figure 5.5). In the solid state, 2 showcases
140
coordination analogous to that of 1, in which the four ligand pyridines coordinate in a square planar
fashion in the equatorial position and two acetonitrile molecules coordinate in the axial position of
the cobalt metal center. However, the pyridine-Co bonds are elongated in the complex, giving rise
to an overall flatter molecule with a larger bridging amine distance (Table 5.1)
144
. We reasoned
that electron withdrawing effects of the CF3 functional group lower the electron density on the
pyridine nitrogen atom, thus weakening and elongating the Co-Nitrogen bond. Consequently, the
pendant amines in complex 2 display a flatter geometry compared to that of the parent complex.
Figure 5.5. Side (A) and top (B) view overlays of 2 (blue) and 1 (black) showing the structural
distortion incurred upon the addition of CF3 groups
Synthesis of 4 was accomplished using a procedure like that of 2. However, crystallization
of 4 proved more challenging. Addition of a small amount of dichloromethane (DCM) to a
dimethylformamide (DMF) solution of 4, followed by diffusion with diethyl ether produced
crystals of a chloride substituted metal complex, indicating that 4 can abstract a chloride from
DCM (Figure 5.6).
Figure 5.6. Side (A) and top (B) view overlays of 4 (pink) and 1 (black) showing the structural
distortion incurred upon the addition of CF3 groups
141
It is important to note that the electrochemistry and characterization done in this work was
performed on the non-chlorinated derivative. Complex 4 showcased similar coordination to that
of 1-3 with all four ligand pyridines in the equatorial positions and a chloride and DMF molecules
in the axial positions. Both the Co-
CF3
py and the Co-
NMe2
py are elongated when compared to the
parent complex at 2.128 Å and 2.059 Å, respectively (Table 5.1). The difference in bond lengths
between the different pyridine environments causes a contortion in the overall geometry making
the cycle flatter and contorted
144,145,237
. Similar geometrical distortion has been previously reported
for other aminopyridine complexes.
We were not able to crystallize complex 3.
Complex Co – Py bond lengths (Å) Pendant amine distances (Å)
1 1.952 5.531
2 2.106 6.075
3 Co-
NMe2
Py
Co-Py
4 Co-
NMe2
Py 2.059 6.136
Co-
CF
3Py 2.128
Table 5.1. Selected structural parameters for complexes 1 through 4.
5.2.3 Electrochemical Characterization.
Complexes 2-4 were investigated electrochemically. In a typical experiment, a DMF
solution of 0.5 mM of metal complex, 0.1 M tetrabutylammonium hexafluorophosphate [TBAPF6,
an electrolyte], and 0.5 mM of decamethylferrocene (Fc*, an internal standard) was prepared and
its electrochemical behavior was probed under N2 and CO2 atmospheres, and in the presence and
absence of protons. Under N2, and scanning to moderately negative potentials, complex 2 has a
reversible feature at -1.56 V assigned to the Co
II/I
couple (Figure 5.7, and table 5.2). Variable Scan
rate (VSR) experiments show a linear relationship between the Co
II/I
peak currents and the square
root of the scan rate, indicating a freely diffusing specie in solution (Figure 5.12). Upon scanning
to more negative potentials, the Co
II/I
couple becomes irreversible and a second, irreversible feature
appears at -2.24 V and is assigned to the Co
I/0
reduction. The electrochemical behavior of complex
2 is reminiscent to that of complex 1 although the Co
II/I
and Co
I/0
potentials are positively shifted.
142
This makes sense as 2 is expected to have a lower electron density on the metal, and thus, be more
amenable for reduction.
Figure 5.7. Cyclic voltammograms of complexes 1–4 (0.5 mM) in 0.1 M [nBu4N][PF6] in
DMF under N2 showcasing the reversible Co
II/I
and irreversible Co
I/0
couples.
Complexes 3 and 4 were investigated under the same conditions to show reversible Co
II/I
couples at -1.75 V and -1.85 V, and irreversible Co
I/0
couples at -2.70 V and -2.35 V, respectively
(Figures S4-9). The shifts in potentials for complex 3 make sense due to the increase of electron
density on the metal brought upon by the electron donating NMe2 groups. The shift in potentials
for complex 4 are not as intuitive. The Co
II/I
couple was observed at –1.85 V, more negative than
complexes 1 and 2 and 3. The Co
I/0
couple of 4 however, was observed at -2.35 V, a more positive
potential than that of complexes 1 and 3. These results can be rationalized by solvation
phenomenon around the metal complex which also influence the redox properties of the metal.
Complex Co
II/I
(V)
Co
I/0
(V)
iCat/iP at 1.5 M TFE Rate (M
-1
S
-1
) Faradic
Efficiency
(%)
1 -1.65 -2.46 210 (10) 11,400 (600) 98
2 -1.56 -2.24 160 (8) 7,600 (400) 5
3 -1.75 -2.77 650 (35) 110,000 (5,000) 85
4 -1.85 -2.35 340(15) 27,500 (1,500) 15
Table 5.2. Selected electrochemical parameters for 1-4
143
Complexes 2-4 all exhibit a current increase around the Co
I/0
couple under an atmosphere
of CO2 (Figure 5.8). For complexes 1, 2, and 3, the onset of catalysis upon addition of CO2 begins
before the Co
I/0
couple, indicating that CO2 binding is rapid and thermodynamically favorable. For
complex 4, catalysis starts at more negative potentials compared to the Co
I/0
couple, however, a
positive shift in the couple is observed, similarly indicative of a fast and favorable binding of CO2
to the Co metal center
238,239
. Due to the nature of the couple, a binding constant can be calculated
to be 45 ± 10 M
-1
. This result is consistent with other literature values such as 46 ± 10 M
-1
for Mn-
(mesbpy)(CO)3Br, 26 ± 8 M
-1
for a previously reported cobalt cyclam (cyclam = 5,7,7,12,12,14-
hexamethyl-1,4,8,1-tetraazacyclotetradeca-4,14-diene, and 28 ± 5 M
-1
for a Ru-
(mesbpy)(CO)2Cl2
238,240,241
.
Figure 5.8. Cyclic voltammograms of complexes 2–4 (0.5 mM) (A-C) in 0.1 M [nBu4N][PF6] in
DMF under N2 and CO2 atmospheres showcasing the current enhancement upon addition of CO2.
Scan rates are 100 mV/s.
Addition of protons in the form of TFE (2,2,2-Trifluoroethanol) gave rise to a current
increase proportional to the concentration of TFE (Figure 5.9 and 5.10). Complexes 2-4 exhibit a
positive shift upon addition of acid which was not observed for complex 1, indicating that the
electronic modifications impact the relative rates or favorability of the two protonation steps.
144
Figure 5.9. Cyclic voltammograms of complexes 2–4 (0.5 mM) (A-C) in 0.1 M [nBu4N][PF6] in
DMF under CO2 atmospheres with varying amounts of [TFE]. Scan rates are 100 mV/s.
Figure 5.10. (A) Plot of the observed rate constants kobs vs. [TFE] for complexes 1–5 (0.5 mM)
in a DMF solution containing 0.1 M [nBu4N][PF6], and CO2 (0.2 M) at 100 mV/s. The linear
relationship indicates that the reaction is first order with respect to TFE. The slopes of the lines
correspond to the overall rate constant. The slopes are: 11,400, 6,700, 110,000, and 27,500, M
–
1
s
–1
for complexes 1-4, respectively. (B) Plot of the log of the rate constant Log(kobs) vs.
Log([TFE]). The slopes of the lines are all roughly equal to one indicating a reaction that is first
order in protons.
145
A plot of the rates (Kobs) extracted from the peak currents (See Experimental Section) of a
titration with TFE shows a linear dependence between rate and [TFE] with slopes of 11,400 M
-1
s
-
1
for 1, 6,700 M
-1
s
-1
for 2, 110,000 M
-1
s
-1
for 3, and 27,500 M
-1
s
-1
for 4. (Figure 5.10A, Table 5.2).
A log-log plot of the rates and [TFE] gives a slope of 1 for all four complexes indicating that
protons are in first order (Figure 5.10B). Interestingly, the observed rates do not scale with the
Co
2/1
couple, Co
1/0
couple, or the overpotential. No correlation was observed between either of the
above quantities.
5.2.4 Controlled Potential Electrolysis
The stability and selectivity of complexes 2-4 was tested using controlled potential
electrolysis (CPE). In a typical CPE experiment, a DMF solution of 0.5 mM of metal complex, 0.1
M TBAPF6, 1.3 M TFE (proton source), and 0.1 mM of Fc* (an internal standard) was electrolyzed
at -2.75 V over the course of one hour. The current was monitored over the course of one hour and
so were the contents of the headspace of the CPE cell. Post electrolysis, the working electrode was
placed in a fresh electrolyte solution and the current was measured. This was done to test for the
presence of heterogenous decomposition products on the electrode (Figures 5.11 and 5.13)
Figure 5.11. Overlay of the current (A) and charge (B) traces for the controlled potential
electrolysis (CPE) experiments for complexes 2-4 measured at -2.7 V vs. Fc
+/0
over one hour.
Electrocheical studies are performed in DMF solutions containing 0.1 M [nBu4N][PF6] under an
atmosphere of CO2 and in the presence of 2,2,2-trifluoroethanol (1.2 M) and catalyst (0.5 mM
each)
146
CPE experiments of 2 reveal both CO and H2 with low faradic efficiencies (~15% for each
gas) and low turnover numbers. No formate was observed in the working compartment solution.
Post CPE analysis reveals the deposition of active intermediates onto the electrode. These results
are in line with other systems that have been functionalized with CF3 functional groups. It has been
shown that the decrease in the electron density on the metal center is concomitant with lower
reaction rates, subsequently facilitating side reactions such as heterogenous decomposition
76
.
Complex 3 produced CO at high faradic efficiencies (75%) with additional H2 formation (faradic
efficiency of 5%). The liquid phase was analyzed, but no CO-containing products were detected.
CV’s of the electrode after catalysis produced low current densities, suggesting that 3 does not get
deposited onto the electrode during catalysis. These results suggest that 3 is a stable and selective
CO2-to-CO reduction catalyst. Finally, CPE of complex 4 produced CO at medium faradaic
efficiencies (45%) with only a small amount of H2 formed (5% faradic efficiency). Post CPE
analysis of the electrode produced high current densities, indicating that a heterogenous product is
deposited onto the electrode during catalysis. These results are consistent with those of 2 and 3.
Catalysis inhibition by the CF3 groups is presumed to facilitate side reactions such as the
protonation of the dimethyl amines, and subsequent deposition onto the electrode.
So far, we have shown that complexes 2-4, all of which feature a cobalt coordinated by an
amino pyridine ligand with different electronic substitutions, react with CO2 and protons under
reducing conditions. CV’s show a positive shift upon addition CO2 indicating that the interaction
between the reduced specie and the substrate are thermodynamically favored and fast. Linear
relationships between the rates and [TFE], along with slopes of 1 for the Log-Logs plots of the rate
and [TFE] indicate a first order dependence on protons. While these observations are consistent
with the mechanism previously proposed for 1, the correlation between the electron donation
ability of the ligand and the rates indicates that electronic modifications play a major role in the
complex reactivity. Interestingly, we do not observe a scaling relationship between neither the
cobalt couples, overpotential, or rate. This result, coupled with the newly observed dependence of
the catalytic onset on [TFE] suggests that the electronic modifications impact the first, second, or
both protonation events in the catalytic cycles. DFT calculations are employed in the following
sections to address these points.
147
5.2.5 Density Functional Theory Calculations of the First and Second Protonations
In the original mechanism, following binding, CO2 is protonated twice to complete the
catalytic cycle. We have previously shown that protonations occur sequentially, with the first
protonation forming a COOH ligand and the second protonation cleaving the C-OH bond to release
water and CO, while regenerating the catalyst. Given the observed reactivity, namely, the
Nernstian shift which occurs during the titration with [TFE], we suspected that a change in the
relative energies of protonation might be the culprit. Reaction energies of X
(I)
–CO2 (X = 1–4) with
a proton from solution to yield X
(II)
–CO2H are computed with reference to the experimental free
energy of solvation of the proton in DMSO (See Experimental section). The relative protonation
energies for these reactions range from 6.5 kcal/mol (complex 2
(I)
–CO2) to -5.6 kcal/mol (complex
3
(I)
–CO2). The same calculation is done to elucidate the reaction energies from the protonation of
X
(II)
–CO2H (X = 1–4) to yield X, CO, and H2O. These range from 6.5 kcal/mol (complex 2
(II)
–
CO2H) to -3.6 kcal/mol (complex 3
(II)
–CO2H). The values are summarized in table 5.3. Two
trends can be extracted from the data. For all four complexes, the first protonation is more
favorable than the second. This result is consistent with the original study in which it was shown
that the second protonation is slower than the first, and rate determining in the catalytic cycle.
Within the data sets for each protonation event, the favorability of the protonation is correlated
with the observed rates of reaction, indicating that the stronger the driving force for protonation,
the faster is the rate.
Complex First Protonation Energy (kcal) Second Protonation Energy (kcal)
1 0 0
2 6.5 5.7
3 -3.5 -0.5
4 -5.6 -3.6
Table 5.3. Calculated first and second protonation energies for 1-4.
5.3 Conclusion
We synthesized and characterized a series of cobalt aminopyridine complexes with
different substitutions on the pyridine backbones that allowed us to examine the effects of
electronic modifications on CO2 reduction catalysis. Electrochemical behavior under atmospheres
148
of N2 and CO2 and in the presence and absence of acid suggests that upon reduction, the cobalt
atom binds to CO2 to make an adduct which is then protonated to release CO and H2O. The activity
of the cycles spanned over two orders of magnitude depending on the substituent used, with no
impact on the reduction potential or overpotential. Analysis of the onset of catalysis in the presence
of various concentrations of TFE suggests that the electronic substituents likely impact catalysis
through the protonation steps. Density Functional Theory suggests that electronic modification
impacts the favorability of both protonation steps. Electron donating substituents increase the
charge on the CO2 ligand, and thus its propensity to get protonated and vise verse. By enabling
systematic control over the nucleophilicy of the metal center and by extension of CO2, the reported
complexes provide a relevant model for biological systems and homogenous catalysts for small
molecule activation.
149
5.4 Experimental Details and Additional Figures
5.4.1 General
All manipulations of air and moisture sensitive materials were conducted under a nitrogen
atmosphere in a Vacuum Atmospheres drybox or on a dual manifold Schlenk line. The glassware
was oven-dried prior to use. All solvents were degassed with nitrogen and passed through activated
alumina columns and stored over 4Å Linde-type molecular sieves. Deuterated solvents were dried
over 4Å Linde-type molecular sieves prior to use. Proton NMR spectra were acquired at room
temperature using Varian (Mercury 400 2-Channel, VNMRS-500 2-Channel, VNMRS- 600 3-
Channel, and 400-MR 2-Channel) spectrometers and referenced to the residual 1 H resonances of
the deuterated solvent (
1
H: CDCl3, δ 7.26; C6D6, δ 7.16; CD2Cl2, δ 5.32; CD3CN, δ 2.94) and are
reported as parts per million relative to tetramethylsilane. Elemental analyses were performed
using Thermo Scientific™ FLASH 2000 CHNS/O Analyzers. All the chemical reagents were
purchased from commercial vendors and used without further purification. Compound E was made
according to literature procedures.
5.4.2 Cyclic Voltammetry (CV)
Electrochemistry experiments were carried out using a Pine potentiostat. The experiments
were performed in a single compartment electrochemical cell under nitrogen or CO2 atmosphere
using a 3 mm diameter glassy carbon electrode as the working electrode, a platinum wire as
auxiliary electrode and a silver wire as the reference electrode. Ohmic drop was compensated using
the positive feedback compensation implemented in the instrument. All experiments in this paper
were referenced relative to ferrocene (Fc) with the Fe
3+/2+
couple at 0.0 V. Alternatively, in cases
when the redox couple of ferrocene overlapped with other redox waves of interested,
decamethylferrocene (Fc*) was as an internal standard with the Fe*
3+/2+
couple at –0.48 V. All
electrochemical experiments were performed with 0.1 M tetrabutylammonium
hexafluorophosphate as supporting electrolyte. The concentrations of the cobalt complexes 1
(II)
–
6
(II)
were generally at 0.5 mM and experiments with CO2 were performed at gas saturation or
varying amounts of CO2 in dimethylformamide (DMF).
150
5.4.3 Controlled-potential Electrolysis (CPE)
CPE measurements were conducted in a two-chambered H cell. The first chamber held the
working and reference electrodes in 50 mL of 0.1 M tetrabutylammonium hexafluorophosphate
and 0.5 M methanol in DMF. The second chamber held the auxiliary electrode in 25 mL of 0.1 M
tetrabutylammonium hexafluorophosphate in DMF. The two chambers were separated by a fine
porosity glass frit. The reference electrode was placed in a separate compartment and connected
by a Vycor tip. Glassy carbon plate electrodes (6 cm × 1 cm × 0.3 cm; Tokai Carbon USA) were
used as the working and auxiliary electrodes. Using a gas-tight syringe, 10 mL of gas were
withdrawn from the headspace of the H cell and injected into a gas chromatography instrument
(Shimadzu GC-2010-Plus) equipped with a BID detector and a Restek ShinCarbon ST
Micropacked column. Faradaic efficiencies were determined by diving the measured CO produced
by the amount of CO expected based on the charge passed during the bulk electrolysis experiment.
For each species the controlled-potential electrolysis measurements were performed at least twice,
leading to similar behavior. The reported Faradaic efficiencies and mmol of CO produced are
average values.
5.4.4 TOF calculations from cyclic voltammetry
121
Equations 1–5 were used to determine TOF from catalytic CVs. The peak catalytic current
(icat) for an EECC process (E = electrochemical, C = chemical step) is given by eq 1, and it
corresponds to the plateau current. This equation assumes a one-electron diffusion current and
pseudo-first-order kinetics (the reaction is first order in catalyst and the concentrations of the
substrates, Q (CO2), is large in comparison to the concentration of catalyst). In eq 1, F is Faraday’s
constant (F = 96 485 C/mol), S is the surface area of the electrode (A = 0.07065 cm
2
for CVs),
𝐶 𝑐𝑎𝑡 0
is the catalyst concentration ([cat] = 0.5 mM = 5 × 10
–7
mol/cm
3
), Dcat is the diffusion constant
of the catalytically-active species (~5 × 10
–6
cm
2
/s), and kcat
is the rate constant of the catalytic
reaction.
𝑖 𝑐𝑎𝑡 = 𝐹𝑆 𝐶 𝑐𝑎𝑡 0
√𝐷 𝑐𝑎𝑡 √2𝑘 𝑐𝑎𝑡 (1)
151
Equation 1 is simplified by standardizing with the current in the absence of substrate (CO2
in this case), as described by eq 2. In eq 2, F is Faraday’s constant (F = 96 485 C/mol), S is the
surface area of the electrode (A = 0.07065 cm
2
for CVs), 𝐶 𝑐𝑎𝑡 0
is the catalyst concentration ([cat]
= 0.5 mM = 5 × 10
–7
mol/cm
3
), Dcat is the diffusion constant of the catalytically-active species (~5
× 10
–6
cm
2
/s), υ is the scan rate (0.1 V/s), R is the universal gas constant (R = 8.31 J K
–1
mol
–1
),
and T is temperature (T = 298.15 K).
𝑖 𝑝 = 0.446 × 𝐹𝑆 𝐶 𝑐𝑎𝑡 0
√𝐷 𝑐𝑎𝑡 √
𝐹𝜐
𝑅𝑇
(2)
Dividing eq 1 by eq 2 allows for determination of icat/ip and allows one to further calculate
the catalytic rate constant (kcat) without having to determine S, 𝐶 𝑐𝑎𝑡 0
, and Dcat. The ratio of equations
1 and 2 produces equation 3 which can be rearranged to produce equation 4 in which kcat can be
solved directly.
𝑖 𝑐𝑎𝑡
𝑖 𝑝 =
1
0.446
× √
2𝑘 𝑐𝑎𝑡
𝜐 𝑅𝑇
𝐹 = 2.24 × √
2𝑘 𝑐𝑎𝑡
𝜐 𝑅𝑇
𝐹 (3)
𝑘 𝑐𝑎𝑡 = (
𝑖 𝑐𝑎𝑡
𝑖 𝑝 )
2
𝜐 2.24
2
𝐹 2𝑅𝑇
(4)
Finally, eq 4 can be simplified into eq 5, from which kcat can be calculated directly.
𝑘 𝑐𝑎𝑡 = 0.387 × (
𝑖 𝑐𝑎𝑡
𝑖 𝑝 )
2
(5)
5.4.5 Binding Constant calculation from CVs
The CV’s for complex 4 under N2 and CO2 are indicative of CO2 binding to the metal
center which can be approximated using the following equation
238,240,241
∆𝐸 = (
𝑅𝑇
𝑛𝐹
) 𝑙𝑛 (1 + [𝐶𝑂
2
]𝐾 𝑄 ) (6)
In Eq (6), ΔE corresponds to the change in potential (59 mV) for the Co
I/0
couple when the
atmosphere is changed from N2 to CO2. R is the universal gas constant (8.314 J K
-1
mol
-1
), T is the
152
temperature Kelvin (298.15 K), F is faraday’s constant (96,485 C mol
-1
), n is the number of
electrons involve in the reduction from Co
I
to Co
0
(1 electron), [CO2] is the concentration of CO2
in DMF (0.2 M) and KQ is the binding constant between CO2 and the cobalt catalyst.
5.4.6 Density Functional Theory Calculation Details
Density Functional Theory (DFT) calculations are performed using the Q-Chem 5.0
150
software package. The B3LYP functional
152-155
is used for all calculations. Calculations are done
using the relatively-fine Lebedev exchange correlation grid
157
with 75 radial and 302 points. The
6-31+g*
158
basis set is used for all calculations. Diffuse functions are included to properly treat
the strong anionic character of the bound CO2 .
Dimethylformamide solvation energies are computed using the SMD implicit solvent
model
163
. Solvent calculations are done, as recommended, at the gas phase optimized geometries.
The SM12 model
164
is also tested and yields similar results, but the CM5 charge component of
the model does not converge for all geometries.
Geometry optimizations are started from initial guesses corresponding to the structures of
complex 1 in [cite our ACS central sci paper], and the resulting DFT minima do not deviate
qualitatively from these initial guesses. All geometric minima are fully optimized to the default
thresholds of the Q-Chem 5.0 software package. Protonation free energies are computed as in
[cite our ACS central sci paper].
153
5.4.7 Synthesis of
CF3
L
2,6-(bis)allylamino-4-(trifluromethyl)pyridine (B), 2,6-dichloro-4-(trifluromethyl)pyridine (5
g, 0.0231mol), copper iodide (440.8 mg, 0.00231mol), L-proline (532 mg, 0.00462mol), and
potassium carbonate (9.60 g, 0.069mol) were added to a nitrogen filled thick walled bomb flask.
Degassed solution of DMSO (60 mL), water (6 mL), and allylamine (17.36 mL, 0.231mol) was
added to dissolve the solids. The flask was then sealed under nitrogen and heated at 120° C for 3
days. Upon cooling to room temperature, the red solution was filtered through celite, and
extracted with ethyl acetate (100 mL) and water (200 mL). The organic layer was separated and
the aqueous layer was extracted with ethyl acetate (2x100m mL). The combined organic
fractions were washed with water (10 x 100 mL) and dried with Na2SO4. Removal of solvent
afforded the crude product as a black oil. The oil was chromotographed on a silica gel column
with a 3:1 mixture of dichloromethane:hexanes as the mobile phase. After the removal of
solvent, a white solid was obtained. (51% yield)
1
H NMR (500 Hz, CDCl3) δ5.93 (m, 2H,
HC=CH2), 5.88 (s, 2H, m-NC5H2), 5.27-5.16 (dd, 4H, HC=CH2), 4.56 (s, 2H, NH), 3.7 (d, 4H,
H2C-CH). 13C{1 H} NMR (126 MHz, CDCl3) δ158.36, 134.92, 116.07, 90.77, 44.54
1
F NMR
(500 Hz, CDCl3) δ-65.46 (s, 1F, CF3).
N2,N6-Bis(6-chloro-4-(trifluromethyl)pyridin-2-yl)-N2,N6-diallyl-4-
(trifluromethyl)pyridine-2,6-diamine (C), NaH (0.988 g, 0.0412mol) and 2,6-(bis)allylamino-
154
4-(trifluromethyl)pyridine (1.06 g, 0.00412mol) were added to a stir bar equipped, oven dried
100mL 3-neck flask under nitrogen protection. THF (30 mL) was slowly added to generate an
amber suspension. The mixture was then refluxed at 80°C for one hour and was then taken off
heat and allowed to cool. 2,6-dichloro-4-(trifluormethyl)pyridine (2.66 g, 0.123mol) was added
to the mixture and the solution was brought back to reflux for 1.5 hours. The solution was
allowed to cool to room temperature and slowly quenched with cold water. The solvent was
removed under vacuum and the residue was dissolved in dichloromethane (50 mL). The organic
layer was washed with water (3 x 100mL), dried with Na2SO4 and concentrated under vacuum to
give a brown oil. The oil was chromotographed on a silica gel column with a 2:1 mixture of
dichloromethane:hexanes as the mobile phase. The product was the second to elute. After
removal of solvent the product is isolated as an orangesolid (81% yield).
1
H NMR (500Hz,
CDCl3) δ 7.32 (s, 2H, central m-NC5H2), 7.13 (s, 2H, outer m-NC5H2), 7.10 (s, 2H, outer m-
NC5H2), 5.92 (m, 2H HC=CH2), 5.17 (dd, 4H, HC=CH2), 4.79 (m, 4H, H2C-CH). 13C{1 H}
NMR (126 MHz, CDCl3) δ156.22, 154.86, 132.64, 117.12, 112.90, 108.75, 104.29, 50.8.
1
F
NMR (500Hz, CDCl3) δ -65.02 (s, 6F, outer CF3), -65.26 (s, 3F, central CF3).
(NAllyl)4-BridgedCalix[4]-4-(trifluromethyl)pyridine (Py4(CF3)4NAllyl4) (D), Pd2DBA3 (55
mg, 0.06mmol), DPPFc (62.1 mg 0.112mmol), and sodium tert-butoxide (111 mg 1.15mmol)
were added to a stir bar equipped, oven dried 100mL 3-neck flask under nitrogen protection. Dry
toluene (100mL) was syringed into the flask and the resultant red mixture was heated to 110°C.
Upon reaching the reaching 60°C, B (112.2 mg, 0.43mmol), and C (226.3 mg, 0.367), were
added to the suspension, causing a color change from red to orange. The reaction mixture was
refluxed for 2.5hr. After cooling to room temperature, the solution was filtered through celite,
155
reduced under pressure, and redissolved in dichloromethane (50mL). The solution was washed
with water (5x100mL) and the aqueous layer was re-extracted with dichloromethane (2x50mL).
The combined organic layers were dried with Na2SO4 and eluted through a silica containing frit.
The resultant organic fraction was reduced under pressure to give a yellow oil. The residue was
chromatographed on a silica gel column using a 3:1 dichloromethane:hexane mobile phase.
Desired product was second to elute, and reduction of solvent under pressure yielded a brown
solid (yield 20%).
1
H NMR (500Hz, CDCl3) δ 6.62 (s, 8H, m, 2H, m-NC5H2), 5.84 (m, 4H,
HC=CH2), 5.26-5.16 (dd, 8H, HC=CH2), 4.38-4.20 (dd, 8H, H2C-CH). 13C{1 H} NMR (126
MHz, CDCl3) δ158.3, 133.05, 116.92, 105.34, 52.51
1
F NMR (500Hz, CDCl3) δ -64.88 (s, 12F,
CF3).
(NH)4-BridgedCalix[4]-4-(trifluromethyl)pyridine (Py4(CF3)4NH4) (
CF3
L), Pd2DBA3 (2mg,
2.1 mmol), DPPF (24 mg 4.3mmol), and potassium tert-butoxide (37.4 mg 334.1 mmol) were
added to a stir bar equipped, oven dried 100mL 3-neck flask under nitrogen protection. Dry
toluene (30mL) was syringed into the flask and the resultant red mixture was heated to 110°C.
Upon reaching the reaching approximately 60°C, D (45.0 mg, 55.6mmol), was added to the
suspension, causing a darkening in color. The reaction mixture was refluxed for 12hr. After
cooling to room temperature, the solvent was removed under reduced pressure and redissolved in
dichloromethane (20mL). The solution was washed with water (3x30mL). The organic layers
were dried with Na2SO4 and eluted through a 2.5cm x 1cm silica containing frit. The resultant
organic fraction was reduced under pressure to give brown oil. The oil was dissolved in a 10:1
Acetone:water mixture (10mL) and excess hydrochloric acid was added. The resultant orange
mixture was heated to reflux for an hour. The acetone was removed under reduced pressure and
156
Na2CO3(aq) was added until the solution reached a pH of 10. The solution was filtered and the
filtrate was washed with benzene. The filtrate was isolated and dried under vacuum to give D as
an off white solid (yield 70%)
1
H NMR (500Hz, CD3OCD3) δ 6.74 (s, 8H, m-NC5H2), 8.64 (s,
4H, NH). 13C{1 H} NMR (126 MHz, CDCl3) δ158.31, 156.28, 150.01, 133.54, 118.31, 115.05,
109.35, 105.03, 50.11
1
F NMR (500Hz, CDCl3) δ -65.74 (s, 12F, CF3).
157
5.4.8 Synthesis of
NMe2
L
2,6-(bis)allylamino-4-(dimethylamine)pyridine (F), 2,6-dichloro-4-(dimethylamine)pyridine
(E) (813.2 mg, 4.28 mmol), Pd2DBA3 (177 mg, 0.193 mmol), DPPFc (193.5 mg, 0.349 mmol),
and sodium tert-butoxide (1.73 g, 18.0 mmol) were added to an oven dried, stir bar equipped,
nitrogen filled thick walled bomb flask. Degassed toluene (250 mL) was added to the solution,
along with allylamine (17.36 mL, 0.231 mol). The flask was then sealed under nitrogen and
heated at 110° C overnight. NOTE: This molecule is air sensitive. Work up must be as fast as
possible. Upon cooling to room temperature, the red solution was filtered through celite, and the
solvent was removed under reduced pressure. The obtained red residue was suspended in
hexanes (80 mL) and sonicated for 25 minutes. The solution was filtered to remove the insoluble
impurities. The solids were further washed with hexanes (2x 80mL) and filtered again. The
hexane fractions were combined. Removal of the solvent gave rise to the product as an orange
oil. The oil was immediately brought into an inert atmosphere glove box, extracted into pentane
(25mL) and mixed with crushed activated molecular sieves (~10 sieve balls). The solution was
stirred for 35 minutes before being filtered. The solvent was removed under reduced pressure to
give the product as an amber oil in 30% yield. NOTE: The oil MUST store under inert
atmosphere.
1
H NMR (500 Hz, CDCl3) δ5.93 (m, 2H, HC=CH2), 5.27-5.16 (dd, 4H, HC=CH2),
5.12 (s, 2H, m-NC5H2), 3.83 (m, 4H, H2C-CH), 2.92 (s, 6H, N(CH3)2) 13C{1 H} NMR (126
MHz, CDCl3) δ158.97, 158.15, 135.95, 115.53, 7.48, 45.24, 39.48
158
N2,N6-diallyl-N2,N6-bis(6-bro-4-(pyridin-2-yl)-N4,N4-dimethylpyridine-2,4,6-triamine (G),
NaH (600 mg, 15.6 mmol) and E (600 mg, 2.58 mmol) were added to a stir bar equipped, oven
dried 100mL 3-neck flask under nitrogen protection. THF (30 mL) was slowly added to generate
an amber suspension. The mixture was then refluxed at 80°C for one hour and was then taken
off heat and allowed to cool. 2,6-dibromopyridine (1.83 g, 7.75 mmol) was added to the mixture
and the solution was brought back to reflux for 1 hour. The solution was cooled to room
temperature and slowly quenched with cold water. The solvent was removed under vacuum and
the residue was dissolved in dichloromethane (50 mL). The organic layer was washed with water
(3 x 100mL), dried with Na2SO4 and concentrated under vacuum to give a brown oil. The oil was
chromotographed on a silica gel column with a 2:1 mixture of hexanes: dichloromethane as the
mobile phase and then washed with diethyl ether to isolate the product as s yellow oil in a 73%
yield.
1
H NMR (500Hz, CDCl3) δ 7.25 (t, 2H, p-pyridine), 7.03 (d, 2H, m-pyridine bromine
adjacent), 6.89 (d, 2H, m-pyridine nitrogen adjacent), 6.30 (s, NMe2-pyridine), 5.99 (m, 2H,
HC=CH2), 5.22-5.12 (dd, 4H, HC=CH2), 4.72 (s, 4H, H2C-CH).
13
C{1 H} NMR (126 MHz,
CDCl3) δ157.52, 157.20, 155.81, 139.35, 138.58, 134.80, 118.39, 116.17, 111.35, 95.04, 50.76,
39.56
N
1
4,N
1
4,N
5
4,N
5
4-tetramethyl-2,4,6,8-tetra(prop-1-en-1-yl)-2,4,6,8-tetraaza-1,3,5(2,6)-
tripyridina-7(1,3)-benzenacyclooctaphane-14,54-diamine (H). Pd2DBA3 (35 mg, 37.9 mmol),
DPPP (31.7 mg, 72.7 mmol), and sodium tert-butoxide (80 mg, 0.725 mol) were added to a stir
bar equipped, oven dried 250 mL 3-neck flask under nitrogen protection. Dry toluene (70 mL)
was syringed into the flask and the resultant red mixture was heated to 110°C. Upon reaching the
reaching approximately 60°C, G (151.0 mg, 0.256 mol) and F (59.4 mg, 0.256 mol) was added
to the suspension, causing a darkening in color. The reaction mixture was refluxed for twelve
hours. After cooling to room temperature, the solvent was removed under reduced pressure and
159
redissolved in diethyl ether. The red solution was filtered through celite and was used without
further purification. Diagnostic proton NMR peaks can be found at 5.85 (singlet) and 6.45
(doublet).
NMe2
L. H was dissolved in a 10:1 acetone:water (11 mL) mixture and HCl was added (5 mL).
The solution was refluxed for one hours after which the volatiles were removed under reduced
pressure. Na2CO3(aq) was added until the solution reached a pH of 10. The solution was filtered
and the filtrate was washed with water, dichloromethane, and diethyl ether. The filtrate was
isolated and dried under vacuum to give
NMe2
L as an off white solid (yield from the coupling of
G and F, 20%) ).
1
H NMR (500Hz, CD3OD) δ 7.49 (t, 2H, p-Py), 6.47 (d, 4H, m-Py), 5.94 (s,
2H, NMe2-Py), 2.99 (s, 12H NMe2). 13C{1 H} NMR (126 MHz, CDCl3) δ140.88, 133.45,
131.83, 129.99, 107.26, 91.93, 59.54.
5.4.9 Synthesis of
Mix
L
N2,N6-diallyl-N2,N6-bis(6-chloro-4-(trifluoromethyl)pyridin-2-yl)-N4,N4-
dimethylpyridine-2,4,6-triamine (I), NaH (700 mg, 18.0 mmol) and E (700 mg, 3.00 mmol)
were added to a stir bar equipped, oven dried 100mL 3-neck flask under nitrogen protection.
THF (30 mL) was slowly added to generate an amber suspension. The mixture was then
refluxed at 80°C for one hour and was then taken off heat and allowed to cool. 2,6-dichloro-4-
160
(trifluormethyl)pyridine (2.25 g, 10.9 mmol) was added to the mixture and the solution was
brought back to reflux for 1 hour. The solution was cooled to room temperature and slowly
quenched with cold water. The solvent was removed under vacuum and the residue was
dissolved in dichloromethane (50 mL). The organic layer was washed with water (3 x 100mL),
dried with Na2SO4 and concentrated under vacuum to give a brown oil. The oil was
chromotographed on a silica gel column with a 2:1 mixture of hexanes:ether as the mobile phase.
The product was the first to elute. After removal of solvent the product is isolated as an yellow
solid (65% yield).
1
H NMR (500Hz, CDCl3) δ 7.14 (s, 2H, m-CF3-Py), 6.89 (s, 2H, m-CF3-Py),
6.32 (s, 2H, outer m-NC5H2), 5.92 (m, 2H HC=CH2), 5.17 (dd, 4H, HC=CH2), 4.72 (m, 4H,
H2C-CH). 13C{1 H} NMR (126 MHz, CDCl3) δ157.83, 157.25, 150.10, 133.77, 116.72, 109.74,
106.42, 96.8, 51.07, 39.54
1
F NMR (500Hz, CDCl3) δ -64.9 (s, 6F).
2,4,6,8-tetraallyl-N
1
4,N
1
4,N
5
4,N
5
4-tetramethyl-34,75-bis(trifluoromethyl)-2,4,6,8-tetraaza-
1,3,5(2,6)-tripyridina-7(1,3)-benzenacyclooctaphane-14,54-diamine (J) Pd2DBA3 (137.8 mg,
0.149 mmol), DPPP (124 mg, 0.286 mmol), and sodium tert-butoxide (300 mg, 0.00312 mol)
were added to a stir bar equipped, oven dried 500 mL 3-neck flask under nitrogen protection.
Dry toluene (250 mL) was syringed into the flask and the resultant red mixture was heated to
110°C. Upon reaching the reaching approximately 60°C, E (591.2 mg, 0.001 mol) and F (232
mg, 0.001 mol) was added to the suspension, causing a darkening in color. The reaction mixture
was refluxed for one hour. After cooling to room temperature, the solvent was removed under
reduced pressure and redissolved in dichloromethane (20mL). The solution was washed with
water (3x30mL). The organic layers were dried with Na2SO4 and eluted through a 2:1
hexane:ether column (last spot to elute collected) followed by a 1:1:1
hexane:ether:dichloromethane column (first sport collected) to give G as an off white solid (yield
30%) . Note: this was not fully purified as evident from the NMR spectra. We believe that
161
the impurities are various isomers in which the allyl bond is isomerized. These impurities
do not inhibit the next step.
1
H NMR (500Hz, CDCl3) δ 6.15 (s, 4H, m-CF3-Py), 6.04 (s, 4H,
m-NMe2-Py), 5.91 (m, 4H, HC=CH2), 5.33-5.14 (dd, 8H, HC=CH2), 4.38-4.12 (dd, 8H, H2C-
CH), 2.89 (s, 12H, N(CH3)2). 13C{1 H} NMR (126 MHz, CDCl3) δ158.42, 134.38, 115.89,
104.87, 91.78, 52.54.
1
F NMR (500Hz, CDCl3) δ –68.92 (s, 6F, CF3).
(NH)4-BridgedCalix[4]-pyridine (Py4(NMe2)2(CF3)2NH4) (
mix
L), Pd2DBA3 (7.0mg, 7.6 mmol),
DPPF (5.5 mg 9.9 mmol), and potassium tert-butoxide (55 mg 4.5 mmol) were added to a stir bar
equipped, oven dried 100mL 3-neck flask under nitrogen protection. Dry toluene (100mL) was
syringed into the flask and the resultant red mixture was heated to 110°C. Upon reaching the
reaching approximately 60°C, C (56.9 mg, 0.074 mmol), was added to the suspension, causing a
darkening in color. The reaction mixture was refluxed for one hour. After cooling to room
temperature, the solvent was removed under reduced pressure and redissolved in diethyl ether
(20mL). The solution was washed with water (3x30mL). The organic layers were dried with
Na2SO4 and eluted through a 2.5cm x 1cm silica containing frit. The resultant organic fraction
was reduced under pressure to give brown oil. The oil was dissolved in a 10:1 Acetone:water
mixture (10mL) and excess hydrochloric acid was added. The resultant orange mixture was
heated to reflux for an hour. The acetone was removed under reduced pressure and Na2CO3(aq)
was added until the solution reached a pH of 10. The solution was filtered and the filtrate was
washed with benzene. The filtrate was isolated and dried under vacuum to give D as an off white
solid (yield 85%)
1
H NMR (500Hz, CD3OCD3) δ 7.94 (s, 4H, NH), 6.42 (s, 4H, m-CF3-Py), 6.00
(s, 4H, m-NMe2-Py), 2.93 (s, 12H,N(CH3)2). 13C{1 H} NMR (126 MHz, CDCl3) δ 13.50,
129.46, 129.39, 88.20, 77.18, 64.04, 24.85.
1
F NMR (500Hz, CDCl3) δ -65.75 (s, 6F, CF3).
162
5.4.10 Synthesis of 2-4
Co(
CF3
L)(BF4)2, 2,
CF3
L (12 mg, 18.5 mmol) and Co(BF4)2(H2O)6 (4.3 mg, 18.4 mmol) were
dissolved in acetonitrile (2mL), giving rise to an orange solution. The solution was sonicated for
15 minutes. The solution was filtered and diffused with diethyl ether to give red crystals in
quantitative yields.
1
H NMR (500Hz, CD3OCD3) δ 39.70 (s, 8H, m-NC5H2), -10.87 (s, 4H, NH).
1
F NMR (500Hz, CD3OCD3) δ -69.98 (s, 12F, CF3), -144.86 (s, 8F, BF4).
Co(
NMe2
L)(BF4)2, 3,
NMe2
L (12 mg, 18.5 mmol) and Co(BF4)2(H2O)6 (4.3 mg, 18.4 mmol) were
dissolved in acetonitrile (2mL), giving rise to an orange solution. The solution was sonicated for
15 minutes. The solution was filtered and diffused with diethyl ether to give red crystals in
quantitative yields.
1
H NMR (500Hz, Py-d5) δ 49.86 (s, 4H, m-NC5H3), 25.25 (s, 4H, m-
NMe2
NC5H2), 12.48 (s, 12H, N(CH3)2, -4.95 (s, 2H, p-NC5H3), -14.27 (s, 4H, NH).
Co(
Mix
L)(BF4)(Cl), 4,
Mix
L (12 mg, 18.5 mmol) and Co(BF4)2(H2O)6 (4.3 mg, 18.4 mmol) were
dissolved in DMF (2mL), giving rise to an orange solution. Two drops of dichlormethane were
added to the DMF solution and the mixture was filtered and diffused with diethyl ether to
precipitate the product in quantitative yields.
1
H NMR (500Hz, MeCN-d3) δ 49.21 (s, 4H, m-
CF3
NC5H3), 19.87 (s, 4H, m-
NMe2
NC5H2), 14.79 (s, 12H, N(CH3)2.
1
F NMR ((500Hz, MeCN-d3) δ
-67.53 (s, 6F, CF3), -144.86 (s, 8F, BF4).
163
5.4.11 Additional Figures
Figure 5.12. Cyclic voltammograms of 2-4 (A-C) in a DMF solution displaying the reversible
one-electron reduction assigned to Co
II/I
couple (Left). And plots showing that the peak current,
both cathodic and anodic, in the cyclic voltammograms (CVs) of 2-4 (A-C) (right). The cathodic
and anodic peak currents increase linearly with the square root of the scan rate, indicative of a
freely-diffusing species.
164
Figure 5.13. Cyclic voltammograms of 2-4 (0.5 mM) (A-C) in a DMF solution containing
[nBu4N][PF6] (0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1 atm) before (red) and after
(blue) controlled potential electrolysis (CPE). After the controlled potential electrolysis, the
working electrode was rinsed (3 × 10 mL DMF) and its electrochemistry was measured in a fresh
DMF solution containing [nBu4N][PF6] (0.1 M), 2,2,2-trifluoroethanol (1.2 M), and CO2 (1
atm) – red. Scan rate is 100 mV/s.
165
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178
Appendix 3.1: Calculated coordinates for 1-6
179
Representative geometries from density functional studies
Listed here are the optimized geometries and transition states computed with DFT and referred to
throughout the text. “Deprotonated” refers to single deprotonation of the aminopyridine ligand at
a pendant amine position.
H 2.5555691768 -0.1573065507 3.8218796098
C 1.8251205521 0.2640788207 3.1389635677
C 0.820186446 1.1084145469 3.5975283504
H 0.7411460957 1.3371108534 4.6560636391
C -0.0859102952 1.6582475862 2.6931960638
H -0.8929423299 2.3008426976 3.0293551339
C 0.0365359718 1.3225317482 1.3460918352
N 1.0223419096 0.5161514734 0.87886802
C 1.9102307245 0.0082126132 1.7676075333
C -1.6146395201 1.0372608925 -0.4837097387
C -3.0021136395 1.1564519284 -0.5410741943
H -3.5224094244 1.8505189288 0.1107004828
C -3.7021019433 0.3291499615 -1.4164880042
H -4.7849822928 0.3861539779 -1.4725816141
C -3.0081061586 -0.5715072885 -2.2168903164
H -3.5304507996 -1.2097171063 -2.9221411648
C -1.6134251021 -0.6035973963 -2.1341168538
N -0.9201047181 0.1781744161 -1.2711743819
N 1.2338286423 -0.4652658683 -3.1148114908
C 0.2353005115 -1.1577735563 -3.7148279069
C 0.3061832457 -1.5672837251 -5.0491626481
H -0.5137377281 -2.1182652624 -5.4982158804
C 1.4221431353 -1.2088821006 -5.7972095019
H 1.4955569301 -1.5004361429 -6.8405930739
C 2.4461280226 -0.47564537 -5.2017207645
H 3.3373775217 -0.2041990911 -5.7577618433
C 2.32343895 -0.1397692026 -3.8546198411
H 5.5758732824 -1.0319454941 1.243033488
C 5.1419953715 -0.7037965011 0.3041474301
C 3.7598977457 -0.5346477664 0.1854378946
N 3.1758456423 -0.1225971736 -0.9658628327
C 3.9745874624 0.1565612507 -2.0261680851
C 5.3635005251 0.0532263503 -1.9700205814
H 5.9680574918 0.2786184529 -2.8423183434
C 5.9468382819 -0.3933640271 -0.7864968093
H 7.0251128932 -0.5002577276 -0.7162787359
N -0.9021199235 -1.4752066504 -2.9652317899
H -1.512874638 -2.1209703736 -3.4532014773
N 3.3526110487 0.5718555171 -3.2154531835
H 4.0207835647 0.9481760989 -3.8798377716
N 2.9439260602 -0.8035271661 1.2894439536
N -0.8807869212 1.8332258607 0.4118702847
H -1.4460894377 2.5778334875 0.806146866
Co 1.1365452133 0.1367831159 -1.1452056658
H 3.4546024529 -1.2535290376 2.0410503415
Listing S1. Coordinates of 1
(II)
.
180
H 2.8141175162 0.0534622282 3.7527277849
C 1.999413346 0.3818608371 3.1153026371
C 1.0091967218 1.2659672851 3.5910627569
H 1.0466872498 1.6179978282 4.617909615
C 0.0050672516 1.6731333481 2.7491895962
H -0.7918628136 2.3323667249 3.0714873752
C -0.0717156697 1.1698883595 1.4148121044
N 0.9466477796 0.3563038566 0.9396559583
C 1.9333400179 -0.0180896408 1.7950679799
C -1.671887836 0.889502666 -0.3582356793
C -3.0506961528 1.1376626594 -0.6359890058
H -3.5599850746 1.8474504047 0.0046324521
C -3.6992274511 0.4405636869 -1.6238992364
H -4.7572450384 0.6004339592 -1.8103531368
C -2.9821099114 -0.4917542254 -2.4019150424
H -3.4639171583 -1.0477093361 -3.1998165451
C -1.6318920335 -0.6431183295 -2.1541831139
N -0.9629775472 0.0216693848 -1.1762555344
N 1.2025155172 -0.4985906237 -3.0769422057
C 0.2272605226 -1.2098029478 -3.6929390594
C 0.3213119311 -1.5973432722 -5.0381198983
H -0.4810744253 -2.1653955365 -5.4973113345
C 1.4231264095 -1.1865539984 -5.7739730085
H 1.5103990154 -1.4544977929 -6.8227371134
C 2.4168471314 -0.4240652652 -5.1615813919
H 3.2997350092 -0.1080852194 -5.7072764563
C 2.2749859038 -0.1197626671 -3.8078057666
H 5.581805246 -1.0969354805 1.2204330882
C 5.1346737461 -0.7491141376 0.2950077555
C 3.7436195023 -0.591968606 0.2024216426
N 3.1402023567 -0.1584559992 -0.9308329366
C 3.9209483061 0.1704760718 -1.9842834902
C 5.3129952581 0.0881616978 -1.9523368264
H 5.9003384107 0.3534852471 -2.8251289448
C 5.9188980696 -0.3924238292 -0.7923006669
H 6.9997270459 -0.4838605264 -0.7397655742
N -0.8918199546 -1.5610492821 -2.950492148
H -1.5103309917 -2.1744474449 -3.4684684551
N 3.2841762365 0.6112348458 -3.1572902076
H 3.9495333514 0.9949369638 -3.8188249316
N 2.9411263744 -0.8894483337 1.2955833251
N -1.1779858792 1.4869273205 0.7322088725
Co 1.0368671593 -0.0172669308 -1.0293460902
H 3.4737555512 -1.3015359504 2.0529708566
Listing S2. Coordinates of 1
(II)
, deprotonated.
181
H 2.3681989638 -0.3070427835 3.8224470482
C 1.6817407582 0.1613407158 3.1243637696
C 0.6541755255 0.9795104929 3.5691500348
H 0.507174339 1.1377775311 4.6334020502
C -0.1894001361 1.6064264694 2.6467968414
H -0.9980447658 2.2414598507 2.9853108995
C 0.0100283884 1.3635612942 1.2922365744
N 1.0125361045 0.5593182736 0.8466987708
C 1.8478500282 -0.0069969361 1.7433136152
C -1.6005800988 1.0723960486 -0.5023102941
C -2.9905755434 1.1015644699 -0.4753667267
H -3.5200740491 1.7882779906 0.1725054239
C -3.6935544379 0.1954856554 -1.2753731554
H -4.7793119179 0.1854031802 -1.2581133476
C -3.0038991446 -0.6855146607 -2.0947858939
H -3.5307494435 -1.3735807263 -2.7482191981
C -1.6037531701 -0.6330120457 -2.0991673806
N -0.91541234 0.2092699451 -1.2997261539
N 1.2305080258 -0.4348526546 -3.1253730505
C 0.2383431414 -1.145864906 -3.713181216
C 0.3142411604 -1.5719653688 -5.0431078961
H -0.5006081313 -2.1352766701 -5.4861635332
C 1.4291935315 -1.2173486073 -5.7936631912
H 1.5055319164 -1.522769872 -6.832861921
C 2.4509212454 -0.4729946963 -5.206279701
H 3.3430063489 -0.2077376565 -5.7639535525
C 2.3220446757 -0.1180370811 -3.8653829963
H 5.544872253 -1.006684593 1.2423832855
C 5.1167640153 -0.6746910658 0.3021604071
C 3.7350013497 -0.4996281385 0.1769327038
N 3.1622982836 -0.0789145546 -0.9765458162
C 3.9666152249 0.1906095547 -2.0346867204
C 5.3539002652 0.0778671571 -1.9732203756
H 5.964362 0.2960797777 -2.8432197194
C 5.9282131953 -0.3685459027 -0.7843261271
H 7.0055019449 -0.481147432 -0.7081129043
N -0.8955767135 -1.4710420698 -2.9629722104
H -1.4978244695 -2.1315497441 -3.4412665675
N 3.3452516505 0.6062405823 -3.2263942876
H 4.0145632426 0.980676284 -3.8908267477
N 2.9158516512 -0.7756794076 1.2759788641
N -0.8113821345 1.9459340562 0.291233474
Co 1.1325278691 0.2307122514 -1.1755258671
H 3.4197506576 -1.2344403056 2.0266123788
C -1.4068128654 3.2581578533 0.6130428026
H -1.7930723377 3.6958186255 -0.3093027141
H -0.6195049196 3.906738426 1.0015715443
H -2.2186711375 3.2046713929 1.3486987772
Listing S3. Coordinates of 2
(II)
.
182
H 2.3396826083 -0.3343456794 3.844034684
C 1.6672438182 0.1358864362 3.1337223427
C 0.6611872144 0.9892737515 3.551542733
H 0.5102790032 1.1768423496 4.610641613
C -0.1562282629 1.6197852161 2.6077159105
H -0.951199987 2.2828186966 2.9233905855
C 0.0481920243 1.3376772451 1.2598110585
N 1.0262207539 0.4980271433 0.8380070877
C 1.8448093806 -0.0653292199 1.753566032
C -1.5601066921 1.0432791148 -0.5318433319
C -2.9505130084 1.1085802354 -0.5052197064
H -3.462009927 1.8234031772 0.1260885857
C -3.6752223862 0.1967046802 -1.2796578384
H -4.7610623324 0.2137190003 -1.2625212715
C -3.0072008766 -0.718580667 -2.0740028044
H -3.5459609947 -1.410289162 -2.7136685798
C -1.6014376619 -0.696169955 -2.0846926347
N -0.893780143 0.146416136 -1.3005969371
N 1.2727614647 -0.6158305281 -3.0983402868
C 0.2059671792 -1.1780200012 -3.7235988561
C 0.156027681 -1.4243301996 -5.0820372674
H -0.7237303145 -1.8734749826 -5.531713496
C 1.2590225956 -1.0313371954 -5.8679931749
H 1.2399907821 -1.1894084457 -6.9424544354
C 2.3498479642 -0.4548421634 -5.2666257796
H 3.2315327639 -0.1599499834 -5.8227589718
C 2.3938796997 -0.2937823825 -3.8484903558
H 5.5183012438 -0.7210258915 1.4177857666
C 5.1105193405 -0.5089155444 0.4346147879
C 3.7461599149 -0.5253152905 0.2181766061
N 3.1707898151 -0.2658555503 -0.9846073557
C 3.9880723438 0.0013979721 -2.0728478595
C 5.397563256 0.1109374216 -1.871921706
H 6.0003511579 0.3559287772 -2.7380894135
C 5.948908426 -0.1624707305 -0.6451275877
H 7.0244611778 -0.1168942121 -0.5004804565
N -0.906833958 -1.5551229359 -2.9223464279
H -1.5244106894 -2.1846081878 -3.4212952982
N 3.5626586307 0.1128362533 -3.337390361
N 2.8890951072 -0.8580394758 1.3031122515
N -0.7645156045 1.9175513152 0.2521881505
Co 1.1955958545 0.0069541208 -1.1938826751
H 3.4059896578 -1.2790258774 2.0661381097
C -1.3366437796 3.2387005822 0.5488966764
H -1.7141141204 3.6675313584 -0.3816131969
H -0.5399720399 3.8815592615 0.9287454616
H -2.1525580808 3.2164740169 1.2838696232
Listing S4. Coordinates of 2
(II)
, deprotonated.
183
H 2.334269234 -0.3245558731 3.7806519233
C 1.6525575931 0.1549992137 3.0854556119
C 0.6255939152 0.9700485269 3.5367249598
H 0.4764227091 1.1159717892 4.6024320054
C -0.2172193289 1.607327436 2.6200989268
H -1.0278582501 2.2366699345 2.9645432864
C -0.0123564552 1.3812231302 1.2638205142
N 0.9934795598 0.5857287132 0.8120379308
C 1.8223648343 0.0009579123 1.7024037495
C -1.6161584961 1.100192111 -0.5390042717
C -3.0061372689 1.1229648921 -0.5192798086
H -3.5434312989 1.8043807574 0.1278142699
C -3.6991458704 0.2158257367 -1.3273858949
H -4.7849461326 0.2012116121 -1.3181169055
C -3.0005801107 -0.6626963948 -2.1417334906
H -3.5209516595 -1.3543232224 -2.7966265649
C -1.5999289061 -0.6057097554 -2.136594175
N -0.9228549551 0.245097327 -1.3369791879
N 1.2202615198 -0.3824230564 -3.1472261509
C 0.2712866385 -1.1583484695 -3.7120467129
C 0.4102247996 -1.674436573 -5.0081052841
H -0.3683220085 -2.2951941483 -5.4399902178
C 1.5398627099 -1.3326190205 -5.7359471429
H 1.669422594 -1.7091689483 -6.7462498046
C 2.5117435733 -0.5000578573 -5.1712332824
H 3.401045741 -0.2363414018 -5.7292638488
C 2.3256879185 -0.0543971852 -3.8677036302
H 5.4887386419 -1.2171602276 1.1229400127
C 5.0648303565 -0.8166734999 0.2075924399
C 3.6943093711 -0.5348656636 0.1222553771
N 3.1370544587 -0.033948812 -1.0003670222
C 3.9305199754 0.243337489 -2.0690771236
C 5.3029739518 0.0229957946 -2.0418816079
H 5.9200644999 0.2411260585 -2.9040671445
C 5.8667309072 -0.5269024491 -0.8860205175
H 6.9336262688 -0.7252042621 -0.8448152684
N -0.8861055736 -1.451047384 -2.9883486145
H -1.4815600362 -2.1221844134 -3.460041698
N 3.2695147632 0.7782589422 -3.2074439191
N 2.8843700626 -0.7747455112 1.2340269702
N -0.8309875619 1.9716106429 0.2630925245
Co 1.1257509298 0.3203566679 -1.2198396428
H 3.3780337407 -1.2508248246 1.9804760224
C -1.4339873654 3.277201138 0.5966143704
H -1.8192243916 3.7230488673 -0.3222649247
H -0.6516086568 3.9254781382 0.9954902147
H -2.2484168921 3.2116089936 1.3285207373
C 4.0655431848 1.676334629 -4.0671172497
H 3.3853043783 2.195306869 -4.7448996778
H 4.8289810921 1.1567934576 -4.6591849389
H 4.5543412956 2.4171221735 -3.4316161238
Listing S5. Coordinates of 3
(II)
.
184
H 2.3340036615 -0.3721642795 3.7147231307
C 1.6529428461 0.1359099854 3.0394403247
C 0.6684449019 0.9893030611 3.5171983831
H 0.5499034012 1.1380573181 4.5865125279
C -0.1712520734 1.6528208828 2.6227471436
H -0.9587631953 2.3018238228 2.983377578
C -0.0117456298 1.4174113431 1.2558995061
N 0.9641329844 0.5998860523 0.7796979152
C 1.781543806 -0.0172456344 1.6518284274
C -1.6311979954 1.108621761 -0.5177984008
C -3.0014887995 1.0440173695 -0.3868434257
H -3.5264921939 1.6525596509 0.3387520637
C -3.7040403597 0.1334193293 -1.2105604352
H -4.7831009559 0.0480484551 -1.1180291938
C -3.0221409961 -0.6313238384 -2.1213776801
H -3.5217101677 -1.322302222 -2.7900770709
C -1.6060488014 -0.4950046036 -2.2667570196
N -0.931022804 0.3520118828 -1.4068949612
N 1.190998051 -0.2697647893 -3.1984914185
C 0.1848014504 -1.0232162265 -3.7751753471
C 0.4386461852 -1.6557731369 -5.0324840964
H -0.3568899567 -2.2627449299 -5.4482713334
C 1.6206528926 -1.4400497668 -5.6925252341
H 1.8032888508 -1.9005342887 -6.6594017679
C 2.6095254121 -0.6082755442 -5.1164143107
H 3.5482548966 -0.429897782 -5.6258749355
C 2.3509034453 -0.0593732902 -3.8793038079
H 5.412959115 -1.2379224791 1.1242039229
C 5.0169586927 -0.8176086761 0.2052648358
C 3.6468832288 -0.5494838209 0.0784928495
N 3.1159753973 -0.021430262 -1.0390353087
C 3.9362844719 0.2792198841 -2.0804085068
C 5.3167420141 0.081966966 -2.0091911561
H 5.9532775279 0.3214542841 -2.8511221855
C 5.8514312135 -0.4851448827 -0.8526836016
H 6.9193528364 -0.6698472346 -0.7815525961
N -1.0451028295 -1.1782789723 -3.2714121551
N 3.304607833 0.7988054673 -3.2258589865
N 2.8050744129 -0.83445822 1.1595333125
N -0.843000107 2.007459796 0.2845504641
Co 1.0631686362 0.3900278001 -1.3190587665
H 3.2882899425 -1.3288208375 1.8997559714
C -1.4809018706 3.2802531161 0.6444339888
H -1.902592941 3.7178010705 -0.2624194858
H -0.717552134 3.9562886487 1.0374068532
H -2.2827958062 3.1827434224 1.3891853008
C 4.1182747926 1.6482966764 -4.104839309
H 3.4505797685 2.1426160822 -4.8129105371
H 4.883037136 1.1002873292 -4.6723587572
H 4.6115298126 2.4110942603 -3.4973327086
Listing S6. Coordinates of 3
(II)
, deprotonated.
185
H 2.388464671 -0.3037579253 3.8250373882
C 1.7123782181 0.1547574874 3.1156319013
C 0.7444610311 1.0543074261 3.5490059168
H 0.6484865478 1.2763635032 4.607808188
C -0.1006822299 1.673695841 2.6294406548
H -0.8691032432 2.3594133784 2.9622445522
C 0.0443307226 1.3551987923 1.2805963301
N 0.9934936076 0.4865555609 0.8505468283
C 1.8264779127 -0.1012612491 1.7442155232
C -1.5930720439 1.0565369984 -0.5031444378
C -2.9829276814 1.1085422387 -0.4750863866
H -3.5008012303 1.8002732881 0.1768952351
C -3.7015808081 0.2205402235 -1.2815056249
H -4.7873322702 0.2294041202 -1.2628498982
C -3.0292275367 -0.6647979326 -2.1114513445
H -3.569364836 -1.3356259998 -2.7719305937
C -1.6287346664 -0.6386056753 -2.1140410908
N -0.9274307398 0.1822785859 -1.3041108941
N 1.2144656526 -0.4780463997 -3.1200886896
C 0.214594653 -1.163983078 -3.7249322992
C 0.2946094339 -1.5738963823 -5.0589543473
H -0.5247945444 -2.1183066636 -5.5169341853
C 1.4229508602 -1.2274312053 -5.7946009102
H 1.5042980302 -1.5218558848 -6.8365872755
C 2.4492753541 -0.50351766 -5.1912601628
H 3.3480639111 -0.2422722459 -5.7400314675
C 2.3149118674 -0.161158436 -3.8464486803
H 5.4990925693 -0.9139896099 1.3275390614
C 5.0676004985 -0.6070199107 0.3837411162
C 3.6833515224 -0.5678740857 0.2115477181
N 3.1286976969 -0.1573197667 -0.9609586103
C 3.9386520615 0.1909154766 -1.9860331886
C 5.3310588442 0.2005925353 -1.8726666195
H 5.9528931823 0.4819108461 -2.7163634516
C 5.8911849301 -0.2018033001 -0.6669768695
H 6.9700739727 -0.2094762485 -0.5435632239
N -0.9300941764 -1.4793041764 -2.9844750602
H -1.5407756922 -2.1237263089 -3.4739138215
N 3.3385306401 0.5542020661 -3.2021201438
H 4.010397412 0.9339535938 -3.8604412498
N 2.8133050699 -0.9759182425 1.247548177
N -0.790298997 1.9237656203 0.2837146249
Co 1.1088486296 0.1315901877 -1.1597913186
C -1.3643892247 3.2507261727 0.5831504866
H -1.7583153972 3.6722051424 -0.3433318479
H -0.5642473543 3.8989743133 0.9451965946
H -2.1663178377 3.2234045051 1.3309804252
C 3.333066618 -1.9947982191 2.1808443557
H 3.84432252 -2.7650158998 1.6012708785
H 2.4880532762 -2.4580983123 2.6933182551
H 4.0263985931 -1.5894470853 2.9279094823
Listing S7. Coordinates of 4
(II)
.
186
H 2.5062805318 -0.1188611982 3.7497231455
C 1.8047312954 0.3299998829 3.0587419205
C 0.9116731785 1.3083868145 3.4896062119
H 0.9004520448 1.6096684595 4.5332019372
C 0.0279739668 1.8907880356 2.5898782525
H -0.6977748504 2.6206225894 2.9237346693
C 0.0541193335 1.4641990729 1.2545509878
N 0.9553237976 0.5454998708 0.8218985456
C 1.8062843521 -0.0198689485 1.7056148461
C -1.607956415 0.9986779317 -0.4588982391
C -2.9655911805 0.8649393077 -0.2680097221
H -3.4862566965 1.4492629995 0.4807137849
C -3.6599809538 -0.0771662087 -1.0645374153
H -4.7270944497 -0.2200413319 -0.9194669929
C -2.9876661135 -0.7895390159 -2.0230554797
H -3.4855808674 -1.4896253436 -2.6835956692
C -1.5890794619 -0.574577933 -2.2356934358
N -0.9108842673 0.272239019 -1.3766451175
N 1.2181613924 -0.3327449554 -3.1798240472
C 0.166354037 -0.9633048048 -3.8276345209
C 0.3512164238 -1.4123853544 -5.1697135654
H -0.4830825296 -1.921491621 -5.6369387832
C 1.5212270916 -1.1515746732 -5.8396501715
H 1.649267652 -1.4700187625 -6.8702644794
C 2.5668656351 -0.4729031031 -5.1812882386
H 3.510993363 -0.2741594117 -5.6782104412
C 2.3693545949 -0.104894938 -3.8646505045
H 5.3939734995 -1.1286623621 1.3356499702
C 5.0021217132 -0.769092624 0.3933770655
C 3.6268242744 -0.6297329307 0.1972974043
N 3.1151134607 -0.1581232812 -0.9673518622
C 3.9614458517 0.1598832911 -1.9725821708
C 5.3547488172 0.081770726 -1.8310129866
H 6.0040520491 0.3433643241 -2.6602127238
C 5.868201209 -0.3893899376 -0.6331930455
H 6.9422308465 -0.4729819304 -0.4949397652
N -1.0479521594 -1.1710587536 -3.3012009466
N 3.4110206727 0.5821600083 -3.1801526095
H 4.1216511069 0.9048970277 -3.8267283036
N 2.714570516 -0.9875001284 1.2140416412
N -0.8458619616 1.9528682661 0.3008937203
Co 1.0706416121 0.2107980892 -1.2529298614
C -1.5127557072 3.2288672924 0.5878927482
H -1.9955990604 3.573551389 -0.3279432529
H -0.7594934045 3.9641231404 0.8821162598
H -2.2717346542 3.1627746891 1.3795531326
C 3.148412023 -2.0260951175 2.1591798643
H 3.5845538387 -2.8501466548 1.5910151359
H 2.2694111933 -2.4002586021 2.6875968064
H 3.8831733586 -1.6776423004 2.8975763016
Listing S8. Coordinates of 4
(II)
, deprotonated.
187
H 2.42377852 -0.2410911106 3.7841444276
C 1.7377217539 0.2116994907 3.0805174334
C 0.774906564 1.1135211202 3.5206687007
H 0.6948606042 1.3441781198 4.5789535213
C -0.0883362529 1.7212591245 2.6098027461
H -0.8565654216 2.4037607929 2.949634584
C 0.0419257631 1.3956683638 1.2612259727
N 0.991634839 0.5316056123 0.8246530814
C 1.8317281241 -0.0576433847 1.709675815
C -1.6007522295 1.0686664722 -0.5151164576
C -2.990693848 1.092695902 -0.4781699785
H -3.519497332 1.7726943002 0.1774791718
C -3.6947020816 0.1910285895 -1.2833108609
H -4.780332522 0.1785782844 -1.2604523949
C -3.0091939238 -0.6829252545 -2.114129279
H -3.5399265646 -1.3667053854 -2.768985542
C -1.6084816468 -0.6311264674 -2.1229367361
N -0.9224138106 0.2103473108 -1.3215544582
N 1.2138761211 -0.4199825409 -3.1259976236
C 0.2634047884 -1.1850179117 -3.7023769531
C 0.4120678773 -1.6962677221 -4.9990623956
H -0.3659674182 -2.3090118444 -5.4431579862
C 1.5536587181 -1.3601819673 -5.7116200123
H 1.692639666 -1.7351674209 -6.7212594917
C 2.5244404164 -0.5341792751 -5.135093962
H 3.4201145287 -0.272961593 -5.6841655833
C 2.3267166553 -0.0890214105 -3.8326801755
H 5.488501279 -1.1403648945 1.1953557487
C 5.0513256583 -0.7618019512 0.280817164
C 3.6660507447 -0.5970506352 0.1596572474
N 3.120819922 -0.0948529926 -0.9746786814
C 3.9179284242 0.2557771769 -2.0142860523
C 5.3044882349 0.1358270138 -1.9475260823
H 5.9314356081 0.4079574092 -2.7867643774
C 5.8654427165 -0.3825861995 -0.7810006781
H 6.943038175 -0.4919152389 -0.7009196768
N -0.902780371 -1.4700652912 -2.9885246297
H -1.5025881791 -2.132567545 -3.4667764078
N 3.2600538354 0.753766505 -3.1696654188
N 2.8017044882 -0.9540649849 1.2153027541
N -0.8069238765 1.9506892447 0.2675559881
Co 1.1167098554 0.2383074584 -1.1933285822
C -1.403021814 3.2670177782 0.5699548084
H -1.8130720181 3.6795288452 -0.3535444267
H -0.6124849028 3.9310837998 0.9244875825
H -2.198019644 3.2253872618 1.3245712807
C 4.0378189832 1.6672121827 -4.0298745748
H 3.3501556867 2.1582875146 -4.7205976187
H 4.8228214242 1.1639948949 -4.6076248967
H 4.4967745136 2.4297729193 -3.3978368593
C 3.2871487582 -1.9883315051 2.1503210112
H 3.7477525999 -2.7903956336 1.5713439268
H 2.4301656913 -2.4033604617 2.6832768584
H 4.0136223183 -1.6094628659 2.8794490286
Listing S9. Coordinates of 5
(II)
.
188
H 2.4468444813 -0.2581354795 3.7223234247
C 1.7578214998 0.2192983312 3.0379910736
C 0.8385702105 1.156997672 3.4998080054
H 0.794020404 1.394198581 4.5589349456
C -0.0279251944 1.7837344214 2.6107218837
H -0.7718382016 2.4850590461 2.9655748504
C 0.0470006561 1.4419206666 1.2554924832
N 0.9679313641 0.5580005424 0.7972989757
C 1.8027462609 -0.05231216 1.6655245826
C -1.6123168399 1.0724371449 -0.487152063
C -2.9810797633 1.0025936519 -0.3399384503
H -3.5002320886 1.6106908304 0.3904409933
C -3.6893994948 0.0906316075 -1.1575186433
H -4.7670879522 0.001994431 -1.0526274059
C -3.0171799977 -0.6703505533 -2.0795011165
H -3.524403546 -1.3594521512 -2.744438551
C -1.6029778268 -0.5325896667 -2.2384743055
N -0.9233949895 0.3129900312 -1.3814368897
N 1.1925385136 -0.310353457 -3.1682825142
C 0.1862528123 -1.0582563095 -3.7509274545
C 0.4458748033 -1.6863586014 -5.0088297149
H -0.3479292589 -2.2896065909 -5.4333482849
C 1.6345820037 -1.4727272528 -5.6587697427
H 1.8228009952 -1.9321684898 -6.625099605
C 2.6226102839 -0.6449482576 -5.0753468057
H 3.5643768651 -0.4668977527 -5.5794965439
C 2.3565003403 -0.0957214941 -3.8394399556
H 5.4199239111 -1.1375358362 1.2101530702
C 5.0104950598 -0.7416086351 0.2900390948
C 3.6287886119 -0.5913958611 0.1229878291
N 3.1068219889 -0.0722824606 -1.0089439657
C 3.9283517749 0.2981044874 -2.0224994321
C 5.3201891046 0.2070127676 -1.9062232073
H 5.9656678767 0.4992655613 -2.7242574269
C 5.8528465707 -0.3228943526 -0.7358930468
H 6.9292402574 -0.4169347109 -0.6239132196
N -1.0453463421 -1.2125171148 -3.2483313422
N 3.3018527599 0.7726810394 -3.1876987411
N 2.7352593037 -0.9786711348 1.1468127838
N -0.8218655056 1.9872720309 0.2946659073
Co 1.0646450924 0.3107049805 -1.2813126701
C -1.4570393925 3.2704120723 0.6204327608
H -1.910820724 3.6663390455 -0.2897809308
H -0.6879162245 3.9688935137 0.9595216226
H -2.2338527935 3.1972755582 1.3939876378
C 4.096841605 1.6371847151 -4.0688888741
H 3.4220664622 2.0989028421 -4.7918437922
H 4.8858043871 1.1055097586 -4.6185040437
H 4.5571152163 2.4253375164 -3.4678144276
C 3.1880573381 -2.0421226346 2.054534441
H 3.6345678221 -2.8399855661 1.4579541502
H 2.3176439258 -2.4490865441 2.572724831
H 3.9200455731 -1.7057297792 2.8012078203
Listing S10. Coordinates of 5
(II)
, deprotonated.
189
H 2.4081871992 -0.277680035 3.7971316852
C 1.7250854199 0.1657679789 3.0847602301
C 0.7414626514 1.0506961359 3.5138474912
H 0.6417591985 1.2740278899 4.5720410244
C -0.1148064067 1.654557536 2.5934799083
H -0.8943767244 2.3280750807 2.9256070396
C 0.0404673176 1.3396527198 1.2448373417
N 1.0017272768 0.4821452078 0.8227826273
C 1.8412011454 -0.0975262869 1.7142396008
C -1.5744450636 1.0599398932 -0.5801021887
C -2.9630724138 1.1672990881 -0.6332324874
H -3.4927893597 1.8893426528 -0.025311088
C -3.660107314 0.294110183 -1.4675551806
H -4.7429972435 0.3523025813 -1.5270615322
C -2.9765546853 -0.6502050093 -2.2265917957
H -3.5165256026 -1.3067711852 -2.8960793767
C -1.5798269595 -0.6984580892 -2.1407287501
N -0.9049182769 0.1452385704 -1.3234855896
N 1.2204733435 -0.4698089539 -3.1144123047
C 0.2634640256 -1.2393285863 -3.6865869975
C 0.3696557758 -1.6392070606 -5.0245383679
H -0.4035586762 -2.2351502622 -5.4911800363
C 1.4688627167 -1.214336473 -5.7634157238
H 1.5639353136 -1.5071986947 -6.8049470175
C 2.44698251 -0.4125328066 -5.1758115931
H 3.3137025581 -0.0960735498 -5.7417085008
C 2.2930426333 -0.0618130346 -3.8359026865
H 5.523572702 -1.1367510869 1.1832283873
C 5.0731279459 -0.7671488268 0.2714570988
C 3.6853625895 -0.6161872536 0.1621568163
N 3.1275803742 -0.1251202053 -0.9705550231
C 3.9091769249 0.2392030531 -2.01644851
C 5.2974371058 0.1279327374 -1.9627510018
H 5.9150839125 0.4059502938 -2.8069907617
C 5.8727669857 -0.3859455789 -0.8011281799
H 6.9518685386 -0.4876179614 -0.7319055032
N -0.839183017 -1.6303562706 -2.8985633077
N 3.2404675866 0.7524791509 -3.1593133375
N 2.8312686978 -0.9757979344 1.2262393128
N -0.7864977406 1.9102529566 0.2404143712
Co 1.1236942094 0.1547001941 -1.1807163091
C -1.3528972251 3.2407229734 0.5386567914
H -1.7186303671 3.6775520621 -0.3923198494
H -0.5555393865 3.8762170634 0.9280360501
H -2.1734747975 3.2134149128 1.2660023484
C 4.0055913976 1.6980548265 -3.9960975865
H 3.3090080213 2.2137438577 -4.6594166464
H 4.7830948034 1.2161723399 -4.6013830547
H 4.4724165839 2.4378489028 -3.3433212465
C -1.5433689515 -2.8618458785 -3.3073250246
H -0.7998321592 -3.6189499477 -3.5615436258
H -2.2128538583 -2.7147760062 -4.1634944282
H -2.1236826977 -3.2278718434 -2.4589432529
C 3.3367450216 -1.994699976 2.1674001015
H 3.813207678 -2.7913087494 1.5938410085
H 2.488501697 -2.4236856745 2.7032724305
H 4.0554470653 -1.5959276216 2.8936062003
Listing S11. Coordinates of 6
(II)
.
190
H 2.6399158484 -0.0726273147 3.8174226313
C 1.8775001549 0.3128221623 3.14766072
C 0.860397267 1.1377355369 3.6159524198
H 0.8000622757 1.3909550058 4.6700943631
C -0.0785263765 1.6351006735 2.7180222209
H -0.8980952898 2.2624630719 3.0542817833
C 0.0304703623 1.273671019 1.3705368515
N 1.015473605 0.4827843016 0.8925905262
C 1.9236281929 0.0218089511 1.779477405
C -1.6300858993 0.9912215543 -0.4717749545
C -3.0196187676 1.1384099007 -0.5487743018
H -3.5374577364 1.8209054792 0.1179264236
C -3.7189075638 0.3616366589 -1.4665840571
H -4.7985733478 0.4443765907 -1.5466244387
C -3.0185846764 -0.5227427639 -2.2804444134
H -3.5305810322 -1.1266278946 -3.0231586947
C -1.6267623137 -0.5885770249 -2.1515259928
N -0.9288488794 0.1484140586 -1.2604211486
N 1.2341013821 -0.5018241485 -3.1135268263
C 0.2226203404 -1.146878512 -3.7341949613
C 0.2596151171 -1.5152536161 -5.0837120756
H -0.5866292142 -2.0203456973 -5.5388288566
C 1.3843125314 -1.1822012599 -5.8313954092
H 1.4424657579 -1.4454657572 -6.8831819582
C 2.4335971035 -0.5079018421 -5.2157388973
H 3.3351864611 -0.2538685391 -5.7643499996
C 2.3209768073 -0.1980948076 -3.8556470706
H 5.5937489262 -0.9064460363 1.3000881847
C 5.1632404951 -0.6302295309 0.3426411168
C 3.7762529113 -0.5169304231 0.1956880191
N 3.1799956115 -0.1604351463 -0.9625527709
C 3.9831911581 0.1039519342 -2.0156662629
C 5.3798279365 0.0383259106 -1.9519063473
H 5.9805595581 0.247800417 -2.8314651848
C 5.9716661965 -0.3406096537 -0.7516990551
H 7.0521756193 -0.4098128884 -0.6699826434
N -0.9158588832 -1.4736172788 -2.9790216024
H -1.5428086939 -2.0756773812 -3.4991758444
N 3.3831453504 0.4748782682 -3.2298233418
H 4.0739696072 0.7814187621 -3.904271961
N 2.9575460822 -0.799857249 1.3015948217
N -0.9222976595 1.7652370282 0.4626251388
H -1.5205760056 2.4586222234 0.8955569344
Co 1.1242913003 -0.0077985716 -1.1121560554
H 3.4927483795 -1.1986261709 2.0636555656
Listing S12. Coordinates of 1
(I)
.
191
H 2.8746868526 0.0977355762 3.7787933946
C 2.0341626544 0.3922608777 3.157336473
C 1.0200046961 1.2413974594 3.6413216224
H 1.0575727915 1.6032969941 4.6661715357
C -0.0103335434 1.6066459162 2.8096181318
H -0.8254981404 2.2403282344 3.139349318
C -0.0807859236 1.0952831462 1.4735737979
N 0.9467264871 0.311204857 0.9955750744
C 1.9478060501 -0.0208371805 1.8346112905
C -1.6609849206 0.8388919794 -0.3305445802
C -3.0288015795 1.1407775095 -0.625438086
H -3.5271986395 1.8373384469 0.0386043597
C -3.6813381193 0.518652045 -1.6608405276
H -4.7291700263 0.7257459887 -1.8637791759
C -2.9728666913 -0.3976153759 -2.4587864384
H -3.4440205077 -0.903608864 -3.296467349
C -1.6293687237 -0.6016507768 -2.1729748573
N -0.9496904452 -0.0108257182 -1.1653945703
N 1.1974937714 -0.5523108804 -3.1274251947
C 0.1959880941 -1.2076009983 -3.7483513554
C 0.2567058229 -1.5786750846 -5.103508195
H -0.5764135074 -2.0991146878 -5.5655532389
C 1.3764931741 -1.2113327501 -5.8388215222
H 1.4472585694 -1.4688649727 -6.892247296
C 2.4063242924 -0.5099690645 -5.220388038
H 3.3054757919 -0.2332244205 -5.7622760779
C 2.28193711 -0.2185560551 -3.8528727183
H 5.5831873511 -0.8220089355 1.315890353
C 5.1429433777 -0.5725662921 0.3547986834
C 3.7538282634 -0.5358942535 0.2225447749
N 3.1096092695 -0.2064978415 -0.9366281124
C 3.9178681219 0.0992645185 -1.9878922554
C 5.3135445081 0.087450469 -1.9358414948
H 5.8901905223 0.3209897833 -2.8266856918
C 5.944367977 -0.2586607354 -0.7430123242
H 7.0272390708 -0.2803411318 -0.6698440072
N -0.9313852662 -1.5282900998 -3.0052848127
H -1.5878248575 -2.0717895702 -3.5524030381
N 3.32180139 0.4575151813 -3.2152069231
H 4.0205176236 0.7673441814 -3.8787363571
N 2.9603588761 -0.8789655451 1.3249964856
N -1.1976126437 1.3963975266 0.797336514
Co 1.1016177713 -0.1522114278 -1.0234968577
H 3.5366532544 -1.2256480287 2.0828392866
Listing S13. Coordinates of 1
(I)
, deprotonated.
192
H 2.4049938529 -0.3518487334 3.7894300982
C 1.6928536356 0.1062901368 3.1094552344
C 0.6043806105 0.8200334986 3.5865937242
H 0.4289733624 0.910734889 4.65416078
C -0.2557364767 1.4310166434 2.6723625336
H -1.1157758913 1.9912582115 3.0173906919
C -0.0045110005 1.2865620779 1.3091604668
N 1.0380508776 0.5621525101 0.8203885654
C 1.8811976288 0.0140436233 1.7230484877
C -1.6244978692 1.1122054926 -0.5015076039
C -3.0171068553 1.2257450959 -0.5437249035
H -3.5389839181 1.9239449599 0.097721213
C -3.7292960301 0.3822101867 -1.3972171829
H -4.8132166802 0.4389296809 -1.4378992292
C -3.0483022458 -0.5236226684 -2.1960397287
H -3.575209018 -1.1680693759 -2.8929583335
C -1.6467146639 -0.5494324331 -2.1191938295
N -0.94933333 0.2327857743 -1.2783998753
N 1.2284235975 -0.4815385308 -3.1078838855
C 0.211774244 -1.1560810383 -3.6961115352
C 0.2567527604 -1.6193113447 -5.0173308889
H -0.5946361245 -2.1422256226 -5.4419909381
C 1.3905911671 -1.3640831464 -5.7777467055
H 1.4519839887 -1.7022818231 -6.8074972405
C 2.4474247589 -0.6695084137 -5.1969011817
H 3.3596262693 -0.4725980632 -5.7514052864
C 2.3287416329 -0.2585804933 -3.8665026312
H 5.6461609141 -0.6969541856 1.2870179062
C 5.2088021598 -0.4632097619 0.3215827821
C 3.8169132706 -0.3982334823 0.1670639685
N 3.2257353453 -0.0955256281 -1.0064349989
C 4.0164080028 0.1524974431 -2.0687479354
C 5.4156419579 0.1454010167 -1.9954201378
H 6.0160190222 0.3491135238 -2.8763438212
C 6.0081639481 -0.173741128 -0.7784002652
H 7.090169988 -0.1994106163 -0.6883820737
N -0.9501067618 -1.4247489319 -2.9574089383
H -1.5783542374 -2.0351960874 -3.4651571147
N 3.4079156326 0.4386396626 -3.2951520182
H 4.090385147 0.7008291614 -3.9960550471
N 3.010743008 -0.6824149003 1.2713156608
N -0.8505201809 1.9208794523 0.3580203338
Co 1.1379956711 0.1180325824 -1.1544223438
H 3.5461477353 -1.0655060023 2.0403029593
C -1.4287469329 3.2085286592 0.7558068704
H -1.7947534458 3.7170656893 -0.1393461327
H -0.6390251227 3.8173578359 1.2006901785
H -2.2559834044 3.1278446033 1.475479352
Listing S14. Coordinates of 2
(I)
.
193
H 2.369410015 -0.4353941286 3.7260421143
C 1.6577316008 0.0474285191 3.0627953632
C 0.5684264638 0.7406144798 3.5655607528
H 0.3939078142 0.7920735827 4.6359195817
C -0.2984147916 1.3776525091 2.6749461085
H -1.1632010785 1.9170206271 3.0407238622
C -0.046377675 1.2851650003 1.3078284016
N 1.0058022926 0.593122281 0.7935869496
C 1.8474743501 0.005889321 1.672990657
C -1.6591309468 1.1594030806 -0.5155233318
C -3.0503777502 1.2797782016 -0.5820646089
H -3.5834520351 1.9638834673 0.0651287379
C -3.7480186678 0.4610359196 -1.4713766311
H -4.8305654072 0.524810273 -1.533180145
C -3.0561464367 -0.431527691 -2.2750827701
H -3.5726758618 -1.0591825089 -2.9947146302
C -1.6557960577 -0.4677136503 -2.1707554404
N -0.9720820371 0.2985838814 -1.3032787155
N 1.2095349568 -0.3642995328 -3.1352381739
C 0.2474642415 -1.1349484828 -3.6894400398
C 0.3850726818 -1.7533213818 -4.9416397394
H -0.4229184004 -2.3565169047 -5.345008676
C 1.5531207218 -1.5510293332 -5.6588848062
H 1.6904358432 -2.0146869854 -6.6309679815
C 2.5489685111 -0.7367210288 -5.1156201043
H 3.4757867992 -0.5718204444 -5.6507818971
C 2.3408456613 -0.1626889813 -3.8631608359
H 5.597897887 -0.8684316465 1.1724154645
C 5.1643782719 -0.5567394562 0.2271976016
C 3.7743277931 -0.404666388 0.0938803944
N 3.1936411472 -0.0094919962 -1.0525468462
C 3.9823545724 0.2774873018 -2.1152641739
C 5.3758668823 0.1828415774 -2.0540322773
H 5.9892367626 0.4024130002 -2.9180376728
C 5.9624155563 -0.2497919983 -0.8638200302
H 7.042186913 -0.3446818933 -0.7937887391
N -0.9550385968 -1.3427477667 -3.0023638303
H -1.5743470736 -1.9637555263 -3.5075532754
N 3.3300333622 0.6873983283 -3.2970250458
N 2.97141879 -0.6834254754 1.2011591429
N -0.900404484 1.9425108884 0.379970102
Co 1.119474034 0.2378593724 -1.1995041785
H 3.4985556175 -1.1038022275 1.9560319044
C -1.4936628533 3.2084764637 0.8223837232
H -1.8573251407 3.7485006729 -0.0551138168
H -0.7137085392 3.8069596703 1.2973241888
H -2.3259067009 3.0914284591 1.5311776831
C 4.1074094726 1.5012009378 -4.2373005601
H 3.4192504862 1.9447738111 -4.9596656901
H 4.8780122501 0.9409795973 -4.7860904895
H 4.5922387831 2.3074442042 -3.6817175807
Listing S15. Coordinates of 3
(I)
.
194
H 2.3035168611 -0.7178060776 3.6227286606
C 1.6013690368 -0.1835619112 2.9876793262
C 0.4911780712 0.4590212521 3.5270274928
H 0.2870117303 0.4170683709 4.5924955646
C -0.3437659573 1.1758240141 2.662405151
H -1.2180681485 1.6909635577 3.0428045262
C -0.055930303 1.2091847396 1.3019773427
N 1.0044396357 0.539992573 0.7441172498
C 1.8272987057 -0.1071456888 1.6099741089
C -1.6503959919 1.252278971 -0.5295288587
C -3.0315265877 1.3977467138 -0.5380976916
H -3.5363543253 2.0405562521 0.1719111815
C -3.7652158895 0.6452423898 -1.477091955
H -4.8496249407 0.7254526205 -1.5037973387
C -3.1070537549 -0.1895382179 -2.3462564399
H -3.6269601401 -0.781709517 -3.0906902638
C -1.6788934505 -0.2664931564 -2.3293583257
N -0.9772980208 0.4551561053 -1.3913749052
N 1.1596673925 -0.2736102438 -3.1807088679
C 0.142001907 -1.0580407278 -3.6952929374
C 0.4149747079 -1.9094414431 -4.8150668843
H -0.3993538534 -2.5335779814 -5.1657384882
C 1.6394982107 -1.8844688897 -5.4334472013
H 1.8402506574 -2.5199578163 -6.2926874698
C 2.6369324138 -1.0089511467 -4.9537625336
H 3.610153108 -0.9528730856 -5.4275211703
C 2.3388577817 -0.2382195412 -3.8427677521
H 5.617827721 -0.6162097406 1.1762736079
C 5.1838205045 -0.3404222761 0.2198442274
C 3.7886551365 -0.3351751084 0.0439277688
N 3.2023153701 0.0177990929 -1.1133480528
C 3.987180796 0.3813695721 -2.158105021
C 5.3862012505 0.4485585958 -2.0470131015
H 5.9986588734 0.7335479873 -2.8923334995
C 5.9760899696 0.0717865868 -0.842027849
H 7.0576554715 0.096767614 -0.7370311368
N -1.1283548954 -1.0519181808 -3.2707513317
N 3.3328283551 0.6836441511 -3.3495861
N 2.9867881359 -0.7303240497 1.1137696846
N -0.8467528539 1.9722292103 0.4071978185
Co 1.0854246574 0.3057136659 -1.2277127876
H 3.532770228 -1.1383321588 1.861435003
C -1.4082283403 3.2100564575 0.9390009772
H -1.7595091623 3.8196721867 0.1020082739
H -0.6171421233 3.7537513898 1.4622205068
H -2.2499062177 3.0688191586 1.6361297481
C 4.0673569445 1.4375975147 -4.3618978614
H 3.3570614821 1.7707644837 -5.1209800991
H 4.8619179757 0.861181608 -4.8610943864
H 4.5181018648 2.3191201241 -3.8957679099
Listing S16. Coordinates of 3
(I)
, deprotonated.
195
H 2.4795820861 -0.2183358644 3.7995138597
C 1.7741001164 0.2158507241 3.102697064
C 0.8127579933 1.1204195191 3.5443029624
H 0.7457766821 1.375515512 4.5978515783
C -0.0622098379 1.6960972952 2.6274332779
H -0.8331722769 2.3795443555 2.9596929473
C 0.0539839824 1.342579356 1.2789908623
N 0.9846757694 0.4649289024 0.8380643076
C 1.830595473 -0.0876336262 1.7382486155
C -1.6003068413 1.026974253 -0.4983683322
C -2.9950958554 1.0735704667 -0.4571365714
H -3.508789668 1.7427232278 0.2215956782
C -3.7189317328 0.2161954292 -1.2882902633
H -4.8047122269 0.2262774088 -1.2699760575
C -3.0420639205 -0.6387692393 -2.1460259639
H -3.5774580249 -1.2883045841 -2.8320393383
C -1.6396597671 -0.6150390105 -2.1346202878
N -0.9287990935 0.174054293 -1.3085393022
N 1.226041741 -0.5121855662 -3.1271442769
C 0.2052157408 -1.1330549099 -3.7585348455
C 0.2504912184 -1.4962827433 -5.109936726
H -0.5995301412 -1.9832025053 -5.5777151638
C 1.3919221271 -1.1859620075 -5.8417541351
H 1.4562840201 -1.4470810851 -6.8937345575
C 2.4501872488 -0.5379433547 -5.2133236456
H 3.3617162755 -0.3010651907 -5.7531854282
C 2.329875052 -0.2281847375 -3.853260491
H 5.4803066823 -0.8086059426 1.4047860062
C 5.0670020104 -0.5476029573 0.4386310244
C 3.6886641937 -0.5727241654 0.2186971944
N 3.1387745031 -0.2147339427 -0.9663715146
C 3.9611652498 0.1245402069 -1.975803489
C 5.3552666731 0.1877638016 -1.8337889072
H 5.9841954739 0.463202639 -2.6749901889
C 5.9045629655 -0.1487027072 -0.6050236691
H 6.9799451152 -0.1121191844 -0.4580399379
N -0.946663178 -1.4500499924 -3.0220439466
H -1.5760843391 -2.0438346611 -3.5480328479
N 3.3982540738 0.4283663777 -3.2229221969
H 4.0991364965 0.7288303845 -3.889197662
N 2.7951377345 -0.9986989146 1.2366553672
N -0.81701207 1.8965943497 0.305518964
Co 1.1044720561 -0.0184412485 -1.1309627133
C -1.4132867561 3.1987330254 0.6208839226
H -1.8349615977 3.6178972373 -0.2952090899
H -0.6241805143 3.8662062842 0.9746735906
H -2.2045429586 3.1574199606 1.3831331072
C 3.3162474029 -1.992462637 2.1808328085
H 3.8320781963 -2.7712844675 1.6151091683
H 2.4738601075 -2.4484236389 2.7061063423
H 4.0124863395 -1.581756125 2.9261429005
Listing S17. Coordinates of 4
(I)
.
196
H 2.7559005673 0.2259398687 3.6183955239
C 1.9782495392 0.5966623832 2.9605015862
C 1.1138252012 1.6100115447 3.3766303611
H 1.1927332223 2.0320215926 4.3742692288
C 0.1234432973 2.0496075759 2.4981617311
H -0.5979006397 2.7902026854 2.819217602
C 0.0439805171 1.4923727239 1.2159481514
N 0.9203198727 0.535387674 0.7785905262
C 1.8307355673 0.0750477123 1.677043184
C -1.6543580038 0.9079914045 -0.4478524084
C -2.9926546543 0.6620211323 -0.1885082687
H -3.5121660769 1.1709804109 0.615387823
C -3.6490084048 -0.2940330635 -0.9960552356
H -4.6954358817 -0.5277020089 -0.8132689694
C -2.9682608022 -0.9104026704 -2.0171044841
H -3.4431834743 -1.6194970973 -2.6861868024
C -1.5966114849 -0.5808811944 -2.2704937983
N -0.9537981328 0.2855659829 -1.4184497065
N 1.2368461817 -0.3030808616 -3.173282085
C 0.1707401786 -0.8358460027 -3.8843258811
C 0.3345828871 -1.1519679236 -5.2679490567
H -0.5196474965 -1.5837093868 -5.7763854923
C 1.5132277983 -0.8734469464 -5.918954183
H 1.6272958743 -1.091929504 -6.9779438828
C 2.5788845795 -0.3107463198 -5.1972663453
H 3.5338353974 -0.0987986903 -5.6697143578
C 2.3871118487 -0.0695154255 -3.8406367442
H 5.3593468301 -1.3217935847 1.389963341
C 4.991884425 -0.9479750821 0.4426800456
C 3.6263205543 -0.7206487699 0.2391809695
N 3.1426224828 -0.2297003831 -0.9248085206
C 4.0014607315 0.0375093149 -1.9249790097
C 5.3931182736 -0.1281900183 -1.7861576689
H 6.05629065 0.0885570239 -2.618306761
C 5.8781407215 -0.6306707879 -0.5892506862
H 6.9455252775 -0.7859092358 -0.4553584265
N -1.0484738616 -1.0934609945 -3.3806336638
N 3.4901575038 0.4910948757 -3.1341969396
H 4.2311505045 0.7382035349 -3.7782923644
N 2.6757739108 -0.9948414074 1.2413572524
N -0.9413285937 1.8986810665 0.3086364569
Co 1.0707141546 0.0596865842 -1.1589886792
C -1.6715844857 3.1286791565 0.5940654481
H -2.238389995 3.4062460708 -0.2969018189
H -0.9571437128 3.9278595424 0.8148098841
H -2.373912797 3.0462563676 1.4392720462
C 3.0404633482 -1.986066167 2.2500416837
H 3.4265409434 -2.8761377172 1.745158786
H 2.1388226319 -2.2617453108 2.8016483248
H 3.7972330244 -1.6422296749 2.9729122846
Listing S18. Coordinates of 4
(I)
, deprotonated.
197
H 2.5282300751 -0.185650587 3.7407952699
C 1.8076229969 0.2517774837 3.0614431126
C 0.8599230755 1.1600656724 3.525653425
H 0.8214963717 1.4166821916 4.5803367474
C -0.042290966 1.733810002 2.6344791484
H -0.8062272648 2.4133407138 2.9899543651
C 0.0382437035 1.3800168246 1.2822958408
N 0.9640680713 0.5097475745 0.8212630462
C 1.826560578 -0.0537239603 1.6964681173
C -1.6228491446 1.0519753487 -0.4919050221
C -3.0184281612 1.0715956281 -0.4529440755
H -3.5464341296 1.7197064097 0.2351530547
C -3.724453347 0.2161583882 -1.3012335671
H -4.8102711021 0.2075222684 -1.2869599689
C -3.0301435337 -0.6175116886 -2.1657451187
H -3.5528739025 -1.2703900468 -2.8583732653
C -1.6279122085 -0.572052036 -2.1494762279
N -0.9332911209 0.2280371129 -1.3178854689
N 1.2198189978 -0.4144859827 -3.1400681998
C 0.2539741349 -1.1397091508 -3.7363237809
C 0.3820002933 -1.6535841562 -5.0356558877
H -0.423655668 -2.2270559054 -5.4842040823
C 1.5463150864 -1.3799044164 -5.7383052807
H 1.6794803928 -1.7614763666 -6.7462619593
C 2.5443211047 -0.6046047444 -5.1442406757
H 3.4625862523 -0.3913263208 -5.6769355764
C 2.3436140023 -0.135853092 -3.8446311156
H 5.4599466723 -0.983001156 1.2819232462
C 5.043611348 -0.6502935788 0.3394541291
C 3.6600689429 -0.5762120054 0.1490162036
N 3.1151078756 -0.1239048894 -1.0022343779
C 3.9328762655 0.2442240806 -2.0139533219
C 5.3275622206 0.1960569819 -1.8975767243
H 5.968015511 0.4712491925 -2.7256407742
C 5.8790510937 -0.2537959704 -0.7015395157
H 6.9577058632 -0.3002015815 -0.5830042049
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H -1.5437095328 -2.0250761903 -3.5404163844
N 3.3163615105 0.6828019067 -3.2110641511
N 2.7622252813 -0.983606746 1.171631875
N -0.8614544853 1.9234093173 0.331763001
Co 1.0994023308 0.0806343535 -1.1610052134
C -1.486531516 3.2054794258 0.6727474252
H -1.9309667165 3.6261958856 -0.2316115422
H -0.7106260565 3.8889954388 1.0252025535
H -2.2659717437 3.1321122239 1.4446746506
C 4.1161012208 1.5405310159 -4.0915724868
H 3.449719177 2.0074039728 -4.8196876383
H 4.9100539667 1.0076270234 -4.6341521727
H 4.5739985642 2.3285834836 -3.4892741674
C 3.2529837824 -2.0089336826 2.0982066989
H 3.725120534 -2.8047093535 1.5178393449
H 2.3994560377 -2.4323686861 2.6323697645
H 3.9780035934 -1.6372465971 2.8365057787
Listing S19. Coordinates of 5
(I)
.
198
H 2.3609597812 -0.5783352613 3.7817618001
C 1.6804081642 -0.0939583301 3.0937303195
C 0.6327509712 0.6845676696 3.5763691505
H 0.4776814319 0.7827210932 4.6468764695
C -0.2113742291 1.3412528974 2.6839566452
H -1.0434510155 1.9336728826 3.0441782822
C 0.0272183031 1.1952009434 1.3146185488
N 1.0296284337 0.427227379 0.8360617372
C 1.8500146986 -0.2044915254 1.7066015621
C -1.5427282395 1.1467067494 -0.5844144106
C -2.8931416726 1.4460544843 -0.8132792468
H -3.4015098826 2.2126233315 -0.2431094084
C -3.58536072 0.7107874761 -1.770784923
H -4.6310614961 0.9266839972 -1.9696289476
C -2.9356670713 -0.3055651516 -2.4674864134
H -3.4552777636 -0.8732965597 -3.229631299
C -1.5924146371 -0.556775438 -2.1752509266
N -0.9063632272 0.1643269668 -1.2624084249
N 1.1834352751 -0.5189617222 -3.103960684
C 0.2373936392 -1.3283581685 -3.6330624943
C 0.3701747185 -1.878571064 -4.9156136
H -0.4063522349 -2.499992721 -5.3422615427
C 1.5122994001 -1.5804906786 -5.6526831137
H 1.6404948061 -1.9973124313 -6.647418694
C 2.4861303201 -0.742331173 -5.1146601777
H 3.3892764126 -0.5181154598 -5.6690074978
C 2.2795392336 -0.2209830489 -3.8345952236
H 5.5490076945 -0.6018071402 1.2843884096
C 5.1000606257 -0.3533940428 0.3304802644
C 3.7228215078 -0.4797942457 0.1299742988
N 3.1296526686 -0.1362739466 -1.0336820803
C 3.8922161011 0.3217138289 -2.0528599621
C 5.281630356 0.4626070713 -1.9295635977
H 5.8862981355 0.8009326179 -2.7609088658
C 5.8804308176 0.1243287213 -0.7198132282
H 6.9546484366 0.2285175956 -0.5978723932
N -0.8940259728 -1.6078460367 -2.832937374
N 3.2286737241 0.665114851 -3.2529470072
N 2.8867383746 -0.9949147656 1.1598090176
N -0.7859963276 1.8725805853 0.3636707158
Co 1.1086557136 -0.017932614 -1.1412429107
C -1.3125736829 3.1771347447 0.7779305973
H -1.5906195195 3.7441813179 -0.1136967565
H -0.5214400863 3.7215689435 1.2969041451
H -2.1874570372 3.1126456496 1.4406089289
C 3.9447629434 1.5453596614 -4.1817376571
H 3.2333939023 1.9264452492 -4.9168962999
H 4.7702562972 1.0523450099 -4.7148902865
H 4.3475445659 2.3934880179 -3.6229072507
C -1.6906403104 -2.78509677 -3.1934185867
H -1.0188508946 -3.6346797576 -3.3379006938
H -2.2912436783 -2.6531771038 -4.1047745833
H -2.361795378 -3.0164861934 -2.364226859
C 3.491860547 -2.0006473018 2.0389229877
H 4.0797725968 -2.6871496276 1.4268645052
H 2.6952020937 -2.5699231228 2.5238230566
H 4.1438023858 -1.5768083336 2.8161719786
Listing S20. Coordinates of 6
(I)
.
199
H 2.7317606104 0.0887720401 3.8674194715
C 1.9236054418 0.4107298472 3.2157954466
C 0.8414470701 1.1401420397 3.7187788223
H 0.7738712696 1.3819019538 4.7746595471
C -0.1519256342 1.5499960622 2.8216236538
H -1.0228522739 2.1011624287 3.1663209005
C -0.0396640075 1.2006517515 1.476264632
N 1.0164868725 0.5048792819 0.9540224672
C 1.9846439694 0.1384749629 1.8483785535
C -1.6613600078 0.9326571588 -0.4377249554
C -3.0313088513 1.161944417 -0.6553935217
H -3.5696423207 1.8482466144 -0.0066779312
C -3.6857173072 0.4714979474 -1.6631834692
H -4.7473518983 0.6158486133 -1.8395253833
C -2.9416547825 -0.4336194299 -2.4382425489
H -3.401522486 -0.9906638281 -3.2490736513
C -1.5879630124 -0.5980541875 -2.1603560046
N -0.9113329739 0.081080492 -1.1968124581
N 1.2331280761 -0.5009178509 -3.0777092645
C 0.2432528087 -1.1938228125 -3.6936093337
C 0.2722041301 -1.553526159 -5.0412361039
H -0.5671364825 -2.0872819996 -5.4781686772
C 1.3757489555 -1.1828814401 -5.8158149091
H 1.4310348035 -1.4456363834 -6.8677824376
C 2.4061581178 -0.4650943874 -5.2012296469
H 3.2967809454 -0.1771739861 -5.7527524495
C 2.2944828563 -0.1515104499 -3.8461224724
H 5.6548251028 -0.9482967483 1.2083096728
C 5.1991544753 -0.6722704156 0.2607807147
C 3.8149856548 -0.427917734 0.2018583274
N 3.1635889575 -0.0642198058 -0.9422248802
C 3.9501035814 0.1058048566 -2.0373118092
C 5.3246751669 -0.1121123372 -2.0635378615
H 5.8777531846 0.0149677348 -2.9893732632
C 5.9683413589 -0.5103290848 -0.8797100012
H 7.0414768749 -0.6743192268 -0.8563367329
N -0.8596761466 -1.55861988 -2.9011069783
H -1.4926704956 -2.1513652611 -3.4253307803
N 3.322531096 0.5707244695 -3.2158910496
H 4.0176115199 0.8637057105 -3.8923537203
N 3.092109528 -0.5711526448 1.3817368003
N -1.0565621258 1.6166184066 0.6126783307
H -1.7076752298 2.2345401667 1.0787148388
Co 1.123861673 0.0116209808 -1.0378388278
H 3.6788619347 -0.8850918837 2.143298944
Listing S21. Coordinates of 1
(0)
.
200
H 2.9135911753 0.2000190852 3.724948836
C 2.0552107244 0.467474056 3.1146299344
C 1.0465896707 1.3245608886 3.5929762194
H 1.0990256507 1.7192327404 4.6063958077
C 0.0004929083 1.6565363793 2.7655619544
H -0.8160630354 2.2936866719 3.0871727481
C -0.0883490509 1.1056789274 1.4447112791
N 0.9349630211 0.3112248763 0.9659303188
C 1.9538644914 0.0077630272 1.8031850312
C -1.6958190691 0.8197381388 -0.3332180601
C -3.0699963 1.106734427 -0.624972855
H -3.5792589602 1.7949631307 0.0406950281
C -3.7109408837 0.4755327256 -1.664164708
H -4.7625740796 0.6706976503 -1.8678774567
C -2.9906049682 -0.4273489218 -2.4680156183
H -3.4500549086 -0.9278371773 -3.316101643
C -1.6412747387 -0.6250299157 -2.1809466617
N -0.9835540272 -0.0254065904 -1.1614473867
N 1.1968770461 -0.4887981872 -3.0529915431
C 0.2121747625 -1.1658570073 -3.7320631219
C 0.2730128831 -1.5065940026 -5.0737646554
H -0.5735237455 -2.0146784917 -5.5324352014
C 1.421213611 -1.1850036075 -5.8294273317
H 1.5030335842 -1.4439595313 -6.8804060422
C 2.4532683469 -0.5018964992 -5.1495782666
H 3.3764077329 -0.234444212 -5.6605316933
C 2.298976429 -0.1638520949 -3.8151115425
H 5.5767560981 -0.9432688291 1.2931861736
C 5.146577712 -0.6580925192 0.3346787724
C 3.7705421276 -0.5466146206 0.2165049929
N 3.1142019751 -0.1556685124 -0.9259259145
C 3.9394756632 0.1215080054 -1.9949246639
C 5.3189739959 -0.0030988224 -1.9696990032
H 5.8860209932 0.2022361399 -2.8758365454
C 5.9715441115 -0.392924087 -0.7797599927
H 7.0521604302 -0.4782586475 -0.7222381416
N -0.9169855713 -1.5500718154 -2.9672416499
H -1.5552883796 -2.0836446121 -3.5457124869
N 3.2943202311 0.6023508904 -3.160402033
H 3.9848549351 0.9171702842 -3.8322793816
N 2.9475407087 -0.8760337625 1.3222034276
N -1.2264955362 1.3873748838 0.7898982423
Co 1.1219309828 -0.1332010214 -1.0877774698
H 3.523331252 -1.1973494403 2.0916923038
Listing S22. Coordinates of 1
(0)
, deprotonated.
201
H 2.2821574854 -0.474120874 3.8155502072
C 1.5920970718 -0.0068971904 3.1168524113
C 0.4320748973 0.6195386159 3.5667081806
H 0.1820483119 0.6393938439 4.6228200242
C -0.3793123435 1.2672362917 2.6162833242
H -1.2789997505 1.7897060392 2.9215523526
C -0.0084399557 1.2427367355 1.2816592379
N 1.0809093883 0.5626851283 0.8051711334
C 1.8940433853 0.0075180479 1.7515341921
C -1.5728342528 1.1470995376 -0.5327888125
C -2.9616744768 1.2847314114 -0.5791948046
H -3.4614814072 2.0160305508 0.044800153
C -3.699242575 0.444093593 -1.417015589
H -4.7802455864 0.531545352 -1.475029412
C -3.0190676198 -0.5074438562 -2.1830513376
H -3.5481076 -1.1606415266 -2.8713790106
C -1.6291060347 -0.5806529779 -2.0762406225
N -0.8987104905 0.2218668908 -1.272018501
N 1.2458748279 -0.608969772 -3.0527011403
C 0.1716064286 -1.1936382871 -3.6570796935
C 0.1064165348 -1.5139915414 -5.0068875471
H -0.7988288035 -1.9530216764 -5.4160500286
C 1.2239823063 -1.2588184073 -5.8242485941
H 1.2161516379 -1.5154698851 -6.8788945214
C 2.3410203354 -0.6849760417 -5.2360749514
H 3.2406527259 -0.4938301468 -5.8160288513
C 2.3264769644 -0.3852739128 -3.8648283973
H 5.7029662906 -0.3795399009 1.3605632901
C 5.2651902698 -0.2532760299 0.3743294595
C 3.8772456562 -0.2891444562 0.2174206947
N 3.2526286329 -0.1285099178 -0.9874498094
C 4.0587138468 0.0626105829 -2.0688479755
C 5.4544376566 0.157692704 -1.9850476309
H 6.0424785835 0.3191736799 -2.8844488598
C 6.067673053 -0.0120297188 -0.7447317602
H 7.148210725 0.037624979 -0.6502580868
N -0.9254593105 -1.5348442853 -2.8321009036
H -1.5674744076 -2.1379923837 -3.3326387763
N 3.4828786632 0.1810779758 -3.3272594727
H 4.1736239494 0.3736149954 -4.0401329945
N 3.1029814133 -0.5592821486 1.3443015799
N -0.763272281 1.953900642 0.2967495733
Co 1.1949675117 0.0305879184 -1.1413419019
H 3.6655982838 -0.8569111225 2.1302257487
C -1.3001501507 3.2466935647 0.7018642386
H -1.6418955879 3.7793235332 -0.1910836843
H -0.4967004861 3.8213369487 1.1698521784
H -2.1419437168 3.1914364974 1.4120256911
Listing S23. Coordinates of 2
(0)
.
202
H 2.4541769195 -0.2070143952 3.8278106854
C 1.7282711692 0.2147523936 3.134935339
C 0.6499416158 1.0015118491 3.5988593001
H 0.5046463313 1.1954061231 4.6574429693
C -0.2053791551 1.5524341671 2.6259545705
H -1.0492912277 2.1669192504 2.9240680392
C 0.0279151391 1.3141753881 1.2795492516
N 1.0416125906 0.4959260338 0.8137851382
C 1.8719301358 -0.0120570804 1.7748121808
C -1.5760997471 1.0223715357 -0.5099699362
C -2.9615761062 1.0533968183 -0.4517589987
H -3.4546145473 1.7341900011 0.2352815513
C -3.72223053 0.2073932151 -1.2809956021
H -4.807862196 0.2318708653 -1.2737259294
C -3.0099141939 -0.6501798714 -2.1494216687
H -3.5320403694 -1.3014579594 -2.848159028
C -1.623943682 -0.6529280778 -2.120598627
N -0.8651505313 0.1465340259 -1.3105302574
N 1.2799027826 -0.6890637957 -3.0996346516
C 0.1856468164 -1.1530057696 -3.7465435717
C 0.1030711752 -1.3191105547 -5.1270028259
H -0.8150572244 -1.6793436302 -5.5833556165
C 1.2242838275 -0.9645739191 -5.9023416411
H 1.1943542485 -1.0670917832 -6.9858742266
C 2.3514662161 -0.4902507813 -5.2746435125
H 3.2513485905 -0.2245001789 -5.8187261842
C 2.404273135 -0.3904048314 -3.8453798786
H 5.5296884883 -0.504840219 1.4811790709
C 5.1348981224 -0.3878530901 0.4755143253
C 3.7658034879 -0.4906796071 0.2396527935
N 3.1887337971 -0.3356982883 -0.9742634107
C 4.0057681223 -0.0937523078 -2.0621548228
C 5.4152677902 0.0774628978 -1.8630366409
H 6.0133556442 0.2878423537 -2.7430897659
C 5.9713391982 -0.0853468073 -0.6165309318
H 7.0454536695 0.017032835 -0.4707441818
N -0.9176927211 -1.550489041 -2.9552277704
H -1.5708032544 -2.0871820694 -3.5137031629
N 3.6013470989 -0.0450760078 -3.3424338904
N 2.9235623267 -0.8414643859 1.3205705374
N -0.7696544344 1.9114292273 0.2596230982
Co 1.1144680748 -0.0857867885 -1.1028551979
H 3.4795029882 -1.1552549188 2.1072989806
C -1.3440997413 3.2091366114 0.5632159979
H -1.7361919461 3.6432956152 -0.3624530567
H -0.5548074097 3.8567563133 0.9590002249
H -2.1670704843 3.1909586392 1.3021309342
Listing S24. Coordinates of 2
(0)
, deprotonated.
203
H 2.3375781285 -0.5752401716 3.783302651
C 1.6785817101 -0.0357138431 3.1088529556
C 0.706976469 0.8499191929 3.5947908062
H 0.5771613207 1.0050560472 4.6612946028
C -0.0784295303 1.5398343764 2.6676793981
H -0.844867234 2.230513784 2.9999758447
C 0.12987897 1.3355313994 1.3057395173
N 1.0463165511 0.4426704897 0.8158639151
C 1.8019581483 -0.2143587235 1.7341470474
C -1.4166956684 1.1788949747 -0.4908534935
C -2.8072095249 1.272111322 -0.5129580122
H -3.3110006654 1.9975121607 0.1151980937
C -3.5387744104 0.4229124938 -1.3461741912
H -4.6215274447 0.4863979033 -1.3937878972
C -2.8383247211 -0.5017606305 -2.1301099894
H -3.3550168181 -1.1645387054 -2.8184807371
C -1.4501510188 -0.557309657 -2.0285389885
N -0.7205521233 0.2550337547 -1.2221056064
N 1.3145506481 -0.3497198889 -2.9227332633
C 0.3803834176 -1.1078403392 -3.5538786411
C 0.4767427286 -1.5068346565 -4.883713776
H -0.3237268447 -2.0900995073 -5.3302308751
C 1.60696854 -1.1352546508 -5.6246560427
H 1.7184616148 -1.4376743943 -6.6612295177
C 2.5778425074 -0.350479476 -4.9969163697
H 3.4695269803 -0.043873685 -5.531507284
C 2.3928818511 0.0397943596 -3.6726998648
H 5.3735850021 -1.450630105 1.2549791268
C 4.9974775556 -0.998105421 0.3418534142
C 3.6335834382 -0.7504023973 0.2042394948
N 3.0816566102 -0.1588818224 -0.8856466563
C 3.9420518713 0.2174120833 -1.8812599426
C 5.3132802402 -0.0273617057 -1.8310791545
H 5.944914415 0.2572617525 -2.6645346697
C 5.8594449631 -0.6430703937 -0.7028161679
H 6.9264874337 -0.8305085919 -0.6322977426
N -0.7294077545 -1.4984069622 -2.7831127199
H -1.3445888024 -2.1161153402 -3.2989392571
N 3.3269322168 0.8566795071 -2.9857738236
N 2.7463383219 -1.1252515222 1.2272406157
N -0.6141578823 2.0245305097 0.3141063789
Co 1.1851105382 0.0837229953 -1.0609621588
H 3.2194342102 -1.6264905869 1.9695830868
C -1.1558059983 3.3274370482 0.6671430647
H -1.5098602888 3.8161661392 -0.2449717763
H -0.353594475 3.9303665572 1.1017243638
H -1.9909132812 3.2942374319 1.3873469266
C 4.146144116 1.7556660263 -3.78329211
H 3.490979913 2.31993183 -4.4528769321
H 4.9133750288 1.2519632252 -4.3954980967
H 4.6504890267 2.4556258136 -3.1110155463
Listing S25. Coordinates of 3
(0)
.
204
H 2.2292668834 -0.5944273325 3.8294274486
C 1.5890523856 -0.0360407851 3.1548345032
C 0.5585799025 0.7620398097 3.6044068039
H 0.335536207 0.8349900262 4.6675269473
C -0.1918852861 1.4988076847 2.6712945107
H -1.0119149385 2.134380582 2.9853819049
C 0.1178841282 1.3591859812 1.321776777
N 1.1037196799 0.5532387421 0.8488892811
C 1.9099250091 -0.0979099953 1.766447524
C -1.4149682028 1.2019784133 -0.4937386171
C -2.7997274863 1.2987033039 -0.557954759
H -3.3139619747 2.0410387701 0.0437413947
C -3.5271592389 0.4316352898 -1.3884294932
H -4.6081645348 0.499213922 -1.4669666922
C -2.7914168156 -0.5191028726 -2.1329737429
H -3.2830523538 -1.2006984496 -2.8232027791
C -1.4120423834 -0.5777117827 -1.9841402349
N -0.6879838654 0.2507517779 -1.1821087947
N 1.3423950267 -0.3453815207 -2.8840460243
C 0.4072333348 -1.1200286994 -3.5011545185
C 0.4603608093 -1.5009332853 -4.8356823333
H -0.3509147394 -2.0923038183 -5.2538683743
C 1.5656498889 -1.106909625 -5.6242143309
H 1.6501746302 -1.3985799855 -6.6668777025
C 2.5411300455 -0.3085459105 -5.0082528952
H 3.4157763023 0.0144047566 -5.5633748522
C 2.3958387612 0.0652917635 -3.6774181885
H 5.4248092564 -1.5195366996 1.1693685913
C 5.0532883328 -1.0407119941 0.2697060243
C 3.6893320429 -0.6184279582 0.2820139435
N 3.1413390416 -0.0509467406 -0.8549145335
C 3.9679143903 0.2304694113 -1.8937630196
C 5.3205008265 -0.0980381738 -1.9220545926
H 5.9246434068 0.1254051264 -2.7937096602
C 5.8619478573 -0.7711108671 -0.8124262034
H 6.9110959034 -1.062268036 -0.8074141536
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H -1.2803183751 -2.1663727222 -3.2058336551
N 3.3461320801 0.8747167876 -3.0040135786
N 3.0401940126 -0.7541792074 1.4500299439
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C -1.1885251777 3.3368661908 0.688543351
H -1.5267127266 3.8423681066 -0.2220963685
H -0.4070099575 3.9399942376 1.160951269
H -2.0456613509 3.2836765912 1.3857187772
C 4.1766676605 1.7435349356 -3.8141311638
H 3.5273746978 2.3309538786 -4.4716285006
H 4.9160914086 1.2186549817 -4.4474928303
H 4.7223118198 2.4241292798 -3.1532256192
Listing S26. Coordinates of 3
(0)
, deprotonated.
205
H 2.5027518747 -0.3130121807 3.7430133539
C 1.8054090084 0.146326001 3.0525216241
C 0.856783929 1.0694902307 3.5052588619
H 0.7867705401 1.3235897552 4.5585753029
C 0.0006091991 1.6576099801 2.5680023555
H -0.7629958346 2.3593882069 2.8818186739
C 0.1324110202 1.323633288 1.2224324594
N 1.0385730505 0.4094514482 0.7686293272
C 1.8532831884 -0.1708772731 1.6973275184
C -1.4664002158 0.974948778 -0.5167000928
C -2.8579351532 1.0016099711 -0.5045581677
H -3.3783626064 1.7224023986 0.1154124823
C -3.574189613 0.0972786465 -1.2966408293
H -4.6593133086 0.1079015143 -1.3149491725
C -2.846814423 -0.8098918026 -2.0802533286
H -3.3474443392 -1.5098409795 -2.7437056588
C -1.4591705979 -0.8028850645 -2.0059941505
N -0.7434169782 0.0545623501 -1.2304118592
N 1.2850802136 -0.4974725015 -2.9605538657
C 0.3479647147 -1.2689483023 -3.5728831641
C 0.3966783638 -1.6147870654 -4.923320928
H -0.4023038914 -2.2108597503 -5.3547135019
C 1.4703676899 -1.1731155626 -5.6988238206
H 1.5416782571 -1.432860526 -6.7505639783
C 2.4497646624 -0.3882687828 -5.0869534066
H 3.3151216986 -0.0349188383 -5.6401007071
C 2.3153119853 -0.066986178 -3.736348651
H 5.4622132294 -0.909931908 1.341823734
C 5.0441606887 -0.5692124132 0.4016359607
C 3.6667319927 -0.5992097975 0.2043766765
N 3.0654338546 -0.129726985 -0.9345711175
C 3.8964046888 0.3028315292 -1.920115063
C 5.2818234216 0.3247749584 -1.8142324873
H 5.8815240504 0.6627062941 -2.6550205735
C 5.878950268 -0.0995474211 -0.6185391199
H 6.9568693955 -0.0788094957 -0.4935324862
N -0.7042428875 -1.7252530161 -2.7625249437
H -1.3019344467 -2.3769517377 -3.2572168863
N 3.2681625172 0.74815957 -3.1034652837
H 3.9414333786 1.1185563125 -3.7639951065
N 2.776915926 -1.1114472352 1.1811523773
N -0.6896193853 1.9002440822 0.2241189725
Co 1.1619532938 -0.0424560638 -1.0978805982
C -1.288252973 3.1941950242 0.5124574657
H -1.7023126457 3.5992449853 -0.4149059753
H -0.5055900862 3.8675241804 0.8733688064
H -2.092977379 3.1649962126 1.2664762217
C 3.2958171941 -2.1157879058 2.0963638908
H 3.8100711931 -2.8842809785 1.5128105212
H 2.4542303711 -2.5761502449 2.6217512521
H 4.0003819056 -1.7244157074 2.8497570859
Listing S27. Coordinates of 4
(0)
.
206
H 2.6270555436 -0.2070031244 3.6432135095
C 1.9067389454 0.2590931204 2.9787480204
C 1.0490823374 1.2683917071 3.4447980326
H 1.0614342655 1.5849025676 4.483963427
C 0.1440231485 1.8341771034 2.5224350433
H -0.5738901931 2.5791288078 2.8467625405
C 0.1511574202 1.4016021497 1.2019943732
N 0.9931127949 0.427318011 0.7294701741
C 1.8299960232 -0.1474958523 1.6521997814
C -1.4973988878 0.9499512838 -0.4881943263
C -2.8760655343 0.8605258632 -0.3194007691
H -3.3870388693 1.5037364237 0.3880840809
C -3.5750666789 -0.1092003424 -1.0605362808
H -4.6510657197 -0.2214603771 -0.9390225363
C -2.8818883091 -0.8935009629 -1.957303739
H -3.3727629732 -1.6211464742 -2.5949404673
C -1.478323208 -0.7191636015 -2.1413096874
N -0.7825126173 0.1463641161 -1.3161666609
N 1.2635799992 -0.3752806084 -3.047835449
C 0.2784429937 -1.1028995179 -3.6968132174
C 0.5029247419 -1.5674752719 -5.0293472611
H -0.2853081646 -2.1620989556 -5.4780902626
C 1.6381679981 -1.205362443 -5.7196719228
H 1.793015564 -1.5336780824 -6.7460692307
C 2.5972133659 -0.4021091588 -5.080677831
H 3.5186646162 -0.1077599719 -5.575726439
C 2.3635987268 -0.0314747574 -3.7570995555
H 5.3524849529 -1.0247840541 1.3772550899
C 4.9739780905 -0.6452661774 0.4337097053
C 3.606503919 -0.6562867385 0.1888797913
N 3.036232831 -0.1425234651 -0.9549903175
C 3.9109981314 0.3074046872 -1.8993585244
C 5.2905933137 0.319526137 -1.7466569828
H 5.9165192323 0.6684586858 -2.5652509454
C 5.8563689857 -0.1506348525 -0.5417885908
H 6.9316707773 -0.1619500867 -0.3894077533
N -0.9294727762 -1.3764349784 -3.1783347194
N 3.3270881682 0.7666789191 -3.0974404616
H 4.0403935287 1.0754614033 -3.7476612552
N 2.664911151 -1.1709519834 1.1215183485
N -0.7432390141 1.9184566021 0.238637311
Co 1.1254252888 0.0315825294 -1.1642378485
C -1.401209194 3.175910532 0.5338640028
H -1.9090875113 3.5246788243 -0.3696325555
H -0.6416493766 3.9112611765 0.8196917807
H -2.14700956 3.1229252352 1.3485555259
C 3.1260745281 -2.1932160258 2.0361619376
H 3.6001412697 -2.9917060434 1.4554035851
H 2.2597169822 -2.6005829422 2.5678789656
H 3.8559389525 -1.8456490362 2.7925905641
Listing S28. Coordinates of 4
(0)
, deprotonated.
207
H 2.4613765925 -0.2582894766 3.6915892971
C 1.7695524843 0.2115996911 3.0026751073
C 0.8417103246 1.1560259573 3.4572096347
H 0.7862012024 1.4195901686 4.5089657274
C -0.0131506748 1.750418604 2.5229449032
H -0.7633788445 2.4658192354 2.8385110015
C 0.1041942798 1.4079730525 1.1786209143
N 0.9966490261 0.48029066 0.7219053934
C 1.802190201 -0.1151409018 1.6496796723
C -1.5033635428 1.0758450762 -0.5592947826
C -2.8958563669 1.1237594917 -0.5552698147
H -3.4103197184 1.8564785476 0.0553713292
C -3.6173575603 0.2206828197 -1.3411130859
H -4.7023407781 0.2470261794 -1.3656195712
C -2.9032186591 -0.7078854581 -2.1074719697
H -3.4122366761 -1.4101983795 -2.7616467455
C -1.5131067477 -0.718465033 -2.0309043014
N -0.7938106224 0.1427030584 -1.2652539871
N 1.2305887035 -0.4577035301 -2.9739134856
C 0.308758297 -1.2587408679 -3.568438702
C 0.3943329558 -1.6853372024 -4.8910690899
H -0.3935952517 -2.305530005 -5.3092518574
C 1.4963270365 -1.293016895 -5.6597883009
H 1.6014754922 -1.618642653 -6.6900543694
C 2.4500697325 -0.4580962629 -5.0710363936
H 3.319771884 -0.1339769759 -5.6305033416
C 2.2777786389 -0.0442463187 -3.7516445308
H 5.3844176768 -1.1376042342 1.220242731
C 4.9694855444 -0.748290813 0.2981558767
C 3.5897452134 -0.6495767664 0.1400052556
N 3.0058378321 -0.1170518925 -0.9735475107
C 3.8389304618 0.2963740064 -1.9740867025
C 5.2246948574 0.1861984961 -1.9016117093
H 5.8394588957 0.4944559933 -2.7390438567
C 5.809767262 -0.3321246154 -0.7413408865
H 6.8887221543 -0.4105882321 -0.6494725499
N -0.7735827817 -1.6629490408 -2.7659382222
H -1.3768723591 -2.3157702475 -3.251822499
N 3.188237257 0.8320665664 -3.1135126062
N 2.6927418974 -1.090743815 1.1417636907
N -0.7176146548 1.9910493003 0.1822633083
Co 1.1069575996 0.0281357993 -1.1321230528
C -1.2997516002 3.2930832266 0.4686222543
H -1.7113820227 3.7015534877 -0.4583309635
H -0.507787059 3.9576590087 0.8252117421
H -2.1022082181 3.2753735366 1.2253239627
C 3.9503012765 1.7372864599 -3.9596317306
H 3.2613309149 2.2291001508 -4.6517098013
H 4.7432831121 1.2481631247 -4.5502302468
H 4.4151514217 2.4975715142 -3.3257294805
C 3.16609606 -2.1115241149 2.0640201448
H 3.6291035234 -2.9155110825 1.4853714808
H 2.3066375196 -2.5172756558 2.6045845077
H 3.900536807 -1.749792743 2.803198213
Listing S29. Coordinates of 5
(0)
.
208
H 2.5261487346 -0.2695950212 3.6074425467
C 1.8243682021 0.2245302748 2.9438402607
C 0.9639955222 1.2270798038 3.4272655253
H 0.9603930037 1.5105586658 4.4758636563
C 0.0873405602 1.8335927265 2.5053744571
H -0.6270933567 2.578699017 2.8377669925
C 0.1203409353 1.4494720566 1.1712604022
N 0.961569585 0.4792602894 0.6841522547
C 1.7744512722 -0.1338669647 1.6029404476
C -1.5272504292 1.0848969043 -0.5398924433
C -2.9136548726 1.0695791961 -0.4122853548
H -3.412092803 1.7459005267 0.2725793491
C -3.6392138246 0.1255456515 -1.1607655649
H -4.723008531 0.0726964759 -1.0717971897
C -2.9619344083 -0.7153148779 -2.0165434136
H -3.4706291916 -1.4336602907 -2.6506310291
C -1.5452921428 -0.6208517248 -2.1597061413
N -0.8324124617 0.2386496615 -1.3419280658
N 1.1968067598 -0.3613117148 -3.0531929856
C 0.2253974455 -1.1410704936 -3.6565888989
C 0.483437673 -1.7234249821 -4.9335918427
H -0.2912290614 -2.3612068994 -5.3458523081
C 1.6352577327 -1.4177924806 -5.6251017374
H 1.8192337548 -1.8390690593 -6.6120303233
C 2.5677508584 -0.5379596841 -5.0471826299
H 3.4857803269 -0.276222062 -5.5604846745
C 2.3028712896 -0.0434350194 -3.7728484479
H 5.2908558388 -1.1257136582 1.2630819511
C 4.9104193271 -0.7207173108 0.331351478
C 3.5400897228 -0.6692872974 0.1105674412
N 2.9733733459 -0.1211131338 -1.0115817545
C 3.8449683151 0.3348809454 -1.9699453733
C 5.2260723153 0.2823021845 -1.8349012879
H 5.8633925472 0.6221452141 -2.6439322374
C 5.7915370529 -0.2435134277 -0.6560987142
H 6.868520051 -0.2946580916 -0.5239871378
N -0.9996895083 -1.353626426 -3.1457834451
N 3.2212689811 0.8413039857 -3.1349372334
N 2.6026159523 -1.1551555432 1.0621421689
N -0.742963769 2.0153262102 0.2035734937
Co 1.0714979858 0.0927597776 -1.1967505764
C -1.3556033471 3.2915651582 0.5152820214
H -1.8351100497 3.6793814046 -0.388028427
H -0.5717200921 3.9891865813 0.8283066562
H -2.1161504241 3.2523374843 1.3170979929
C 4.0043833253 1.7092025657 -3.9920765249
H 3.3389477445 2.1633220235 -4.7319476547
H 4.8241236422 1.202312737 -4.5343216834
H 4.4456730679 2.501290502 -3.3782143072
C 3.0511144049 -2.1933243375 1.9657570597
H 3.5060268112 -2.9958346123 1.3758287335
H 2.1813132302 -2.5888492461 2.5002825506
H 3.7920709557 -1.8632236647 2.7188519685
Listing S30. Coordinates of 5
(0)
, deprotonated.
209
H 2.5375642996 -0.4152877471 3.645047456
C 1.8259914406 0.0452699438 2.9700530331
C 0.8525923332 0.9261694554 3.4536621907
H 0.7790005945 1.1449847498 4.5145718913
C -0.0233319096 1.5188270705 2.5377453817
H -0.8043901299 2.1893578548 2.8760558538
C 0.1135717767 1.2325706584 1.1817059705
N 1.0427750831 0.3567831174 0.6988249903
C 1.8776645259 -0.2298988468 1.6057910731
C -1.4675159376 0.9450478756 -0.6045572063
C -2.8571405195 1.0090112382 -0.6705746486
H -3.3976603249 1.7283197544 -0.0668942782
C -3.5428672806 0.1313837042 -1.5172119869
H -4.6246208899 0.1714989133 -1.6009861845
C -2.8016150451 -0.7997644159 -2.2526493127
H -3.2946393641 -1.4817609473 -2.9352730186
C -1.4174363292 -0.8382413105 -2.1038880989
N -0.7334103803 0.0282704668 -1.3007922705
N 1.2884754074 -0.4334134903 -3.0211631862
C 0.3877337336 -1.2569139369 -3.6333876923
C 0.4396188401 -1.5574570098 -4.9922391407
H -0.3226097536 -2.1836913964 -5.4403873748
C 1.4800001536 -1.0361441388 -5.7688432148
H 1.5540487952 -1.2687385071 -6.8267873205
C 2.4220674792 -0.207187592 -5.1501680276
H 3.2544073061 0.1982140236 -5.7131819587
C 2.2838701849 0.0882699849 -3.796204866
H 5.5098998955 -1.0488375995 1.1247364121
C 5.0677654633 -0.6546943594 0.2174074892
C 3.683242226 -0.6240232075 0.0704552404
N 3.0653030678 -0.0922379649 -1.024618237
C 3.8655971703 0.4005005604 -2.0148992585
C 5.2563537612 0.3609272939 -1.9532292417
H 5.8484328687 0.7286842667 -2.782820294
C 5.8758543958 -0.1644661762 -0.8140889225
H 6.9582092236 -0.1916174392 -0.7328440205
N -0.6204043756 -1.7848192016 -2.7917598663
N 3.1843112081 0.951676364 -3.1264985531
N 2.8169213131 -1.1397528864 1.0643915469
N -0.7190586463 1.8317246093 0.2060248477
Co 1.1656408446 -0.0349810177 -1.161945957
C -1.3264791311 3.1113943743 0.5383422419
H -1.7210679262 3.558327072 -0.3782322267
H -0.5531626665 3.7685363733 0.9453091684
H -2.1469180555 3.0462362655 1.2726925532
C 3.8983785293 1.9299669015 -3.932752953
H 3.1805762731 2.4327329175 -4.5864330686
H 4.6979033134 1.5021315108 -4.5606106113
H 4.3459437895 2.6716879851 -3.2655491805
C -1.2603892644 -3.0235197667 -3.2075018641
H -0.4835143866 -3.739878785 -3.4883183093
H -1.9525318661 -2.9121620136 -4.0590232191
H -1.8209602702 -3.4271451884 -2.3600154128
C 3.3485444437 -2.1629368685 1.9515937032
H 3.8524090501 -2.9211066838 1.3459466812
H 2.51480843 -2.6328106395 2.4805023837
H 4.0650372321 -1.7857961688 2.7006708744
Listing S31. Coordinates of 6
(0)
.
210
H 2.7603965466 0.0080123296 3.7128129562
C 1.9522136084 0.348034007 3.0717663072
C 0.9510674852 1.1837916244 3.5576992782
H 0.9461459428 1.4924561371 4.5991411328
C -0.0407824876 1.6187077969 2.6884412525
H -0.8507827543 2.2551595678 3.0321995673
C 0.0016832046 1.190847055 1.3524303463
N 0.9757150922 0.4000034354 0.8562243713
C 1.92921927 -0.0047598828 1.7173347356
C -1.6683671386 0.8859031659 -0.4942225468
C -3.0508983604 1.0742658721 -0.6456264975
H -3.5811010944 1.7668960041 0.0014011203
C -3.7207386245 0.3347307345 -1.6112926333
H -4.7912858112 0.4526394991 -1.752422891
C -2.9972964081 -0.5584556422 -2.3962758118
H -3.4796373611 -1.1356563369 -3.1797249467
C -1.6159867431 -0.6594320805 -2.1933136062
N -0.9448481591 0.0440416261 -1.2610847624
N 1.2688718197 -0.6061207904 -3.159794193
C 0.231585515 -1.205661616 -3.7755089826
C 0.2116301708 -1.5119118413 -5.1412596521
H -0.6634697962 -1.9768224065 -5.5859054749
C 1.3112791954 -1.1581802017 -5.9176671645
H 1.3241349963 -1.3648473374 -6.9839865096
C 2.3912532835 -0.5344414308 -5.307026248
H 3.2766106893 -0.2603009793 -5.8730230581
C 2.3340104909 -0.2916073976 -3.9258344689
H 5.5819179088 -0.7827431962 1.2985133497
C 5.165430251 -0.5634271154 0.3197095627
C 3.7786255058 -0.5341570572 0.132439741
N 3.1898357146 -0.2433394936 -1.0436305956
C 4.0054583337 0.0303233226 -2.0829425009
C 5.4052100661 0.0526619147 -1.9817881485
H 6.011820992 0.2800918503 -2.8533845206
C 5.9881562119 -0.2530980607 -0.7592435063
H 7.0685569476 -0.2488639906 -0.6468033278
N -0.8911386874 -1.5578310982 -3.0010069112
H -1.5268071186 -2.1271508173 -3.5466333332
N 3.4443953779 0.2995581732 -3.3284777056
H 4.1294812727 0.609910369 -4.0042519904
N 2.9542559003 -0.8406807132 1.2329873886
N -1.0253078249 1.6067262657 0.508685653
H -1.6282359405 2.294228863 0.9400930889
Co 1.1393755489 0.1113129119 -1.2040115696
H 3.5141503846 -1.1875057831 2.0024984479
C 1.3027532797 2.1053410953 -1.6919484774
O 2.1044072258 2.7014134104 -0.9554963973
O 0.5753360779 2.4119682376 -2.6496398678
Listing S32. Coordinates of 1
(I)
-CO2.
211
H 2.5582356106 -0.1786755242 3.7480821484
C 1.7937286275 0.250773879 3.1102025614
C 0.6996551513 0.9113616653 3.6147378546
H 0.5522914484 1.001722135 4.689614509
C -0.2358344698 1.4645671501 2.7238405858
H -1.1335819301 1.96538242 3.0751031668
C -0.0086941358 1.2952008345 1.3587681313
N 1.0635562157 0.673796247 0.8295034167
C 2.0137335122 0.1738674417 1.6951826412
C -1.6605317993 0.9998862265 -0.4463304008
C -3.052920375 1.0031107706 -0.4215053076
H -3.5790972096 1.6076388765 0.3117503912
C -3.7499520168 0.1880991414 -1.3372954477
H -4.8361819632 0.1698702057 -1.3560104834
C -3.0088693551 -0.5855322493 -2.2147659606
H -3.4979797945 -1.2135973345 -2.956771741
C -1.6029844998 -0.5122905444 -2.1887535983
N -0.9075330565 0.2684045363 -1.3080822669
N 1.289304961 -0.3820202504 -3.191637453
C 0.2792115341 -1.0782100455 -3.7947502497
C 0.3751881257 -1.6113274854 -5.0943224677
H -0.4755344492 -2.1404287 -5.5193490348
C 1.5263586505 -1.4024625615 -5.8351694908
H 1.6146219492 -1.7803168786 -6.8500638764
C 2.5786966222 -0.6799670222 -5.235110153
H 3.5166414243 -0.5104307776 -5.7560795177
C 2.411593544 -0.2065505623 -3.9364267962
H 5.5932529392 -1.0031078857 1.1625993577
C 5.1996623513 -0.6923661205 0.2012092139
C 3.8126784605 -0.3314547115 0.1561061311
N 3.2447661967 0.0451672858 -1.0427902782
C 4.046378801 0.1293551663 -2.1228028941
C 5.4146648964 -0.1384624754 -2.1200192649
H 5.9932946571 -0.0601366203 -3.0361446358
C 5.9929737104 -0.5688836337 -0.9140206283
H 7.0542393886 -0.8076655555 -0.869994855
N -0.9206064 -1.279517507 -3.1244323015
H -1.5568433498 -1.8436144301 -3.6708896392
N 3.4575667361 0.5206442525 -3.3478856415
H 4.1742579096 0.7271601167 -4.0326864119
N 3.1925448206 -0.361970508 1.3454287951
N -0.9728023607 1.8163652047 0.4638551763
H -1.6195743825 2.4200230825 0.9562502339
Co 1.1636112173 0.5027769897 -1.3080987815
C 1.135274929 2.5238421117 -2.0360943812
O 1.9248621106 3.1361967711 -1.3191799005
O 0.3808350464 2.7133068726 -2.9861104551
Listing S33. Coordinates of 1
(I)
-CO2, deprotonated.
212
H 2.3272222157 -0.3673311437 3.8020201422
C 1.6414567126 0.1141765523 3.1106513377
C 0.5163699281 0.7849223728 3.5619125325
H 0.2875952654 0.8222735804 4.6233178857
C -0.3164540621 1.4189032602 2.6364390403
H -1.2064224566 1.9437801247 2.9625807682
C 0.0002377065 1.3239852485 1.2812521416
N 1.071264175 0.6454467503 0.821853673
C 1.8933284707 0.0879370165 1.7286410055
C -1.5960441811 1.1383780865 -0.5482110873
C -2.989978636 1.2421264965 -0.5503006851
H -3.4952124622 1.9334845622 0.1124435463
C -3.7252844415 0.4000503363 -1.3851895155
H -4.810701325 0.4454030939 -1.3940168007
C -3.0512672023 -0.4920460959 -2.2044797502
H -3.5855699771 -1.1436200393 -2.8900108469
C -1.647787916 -0.512747395 -2.160548613
N -0.921969749 0.2660394454 -1.3343358007
N 1.1778925011 -0.4610970195 -3.1681566732
C 0.1918255652 -1.1834107954 -3.736452996
C 0.2923741636 -1.7465352454 -5.0188677905
H -0.5336643758 -2.3189807703 -5.4305273621
C 1.4530640799 -1.5315772906 -5.7489593764
H 1.5629223675 -1.9520626733 -6.7445214685
C 2.4759033738 -0.7719593308 -5.1855749606
H 3.4097258069 -0.6061587287 -5.7147384402
C 2.2946983578 -0.2669079039 -3.8938421634
H 5.6671918924 -0.5709471137 1.2214104763
C 5.2119830118 -0.3492913837 0.2606257949
C 3.815315946 -0.2740054774 0.1444868476
N 3.1821984649 0.0135592753 -1.0150580472
C 3.9573374113 0.2242856526 -2.0978673784
C 5.3565707611 0.1917790287 -2.0678411692
H 5.9279457652 0.3578983117 -2.9765500667
C 5.9892865882 -0.1048433169 -0.8639651273
H 7.0730245621 -0.1497472488 -0.8060159517
N -0.9913002158 -1.3810733962 -3.0316505292
H -1.6235603019 -2.0159137528 -3.4999988242
N 3.3286082855 0.5063282309 -3.3254668152
H 4.0201651537 0.7384906902 -4.0280902065
N 3.0634243365 -0.5202410525 1.2905870785
N -0.8156454871 1.9627202941 0.301602472
Co 1.1170829584 -0.0657425822 -1.1349833061
H 3.6063666866 -0.9249065477 2.0410894552
C -1.400872367 3.2419443182 0.6960125441
H -1.7689531623 3.7496063457 -0.1998725361
H -0.6169090365 3.8554595005 1.1471391266
H -2.2325843773 3.164365579 1.414206107
C 0.9575078302 -2.0600878163 -0.5976760762
O 0.1192009261 -2.2305995263 0.3015079811
O 1.7241404627 -2.787120507 -1.2475995922
Listing S34. Coordinates of 2
(I)
-CO2.
213
H 2.3932215969 -0.1280494574 3.855941485
C 1.6882601723 0.2756011594 3.1331466256
C 0.5951776334 1.0506860287 3.5399162204
H 0.4138952073 1.2489335284 4.5928060407
C -0.2357270381 1.5954441974 2.551767474
H -1.0884029652 2.2086112677 2.8232897601
C 0.0436880015 1.3404701069 1.2117402512
N 1.0600540368 0.526616576 0.8040864068
C 1.8841449607 0.0468022424 1.7702348814
C -1.551527707 1.0178031698 -0.5641938436
C -2.9397465745 1.0539226679 -0.463774269
H -3.4180482979 1.7468559607 0.2201913274
C -3.707009832 0.1869288986 -1.2534996917
H -4.7925938131 0.2071322479 -1.2117636718
C -3.0370881393 -0.680095277 -2.1258911977
H -3.5836797306 -1.3379573292 -2.7974871088
C -1.6416920596 -0.6727184584 -2.1472332783
N -0.8833432439 0.1278827862 -1.3546236117
N 1.2496566079 -0.6897474035 -3.1376844786
C 0.1699764747 -1.1653709685 -3.7885505547
C 0.1127781086 -1.3662448156 -5.1686843199
H -0.7934418432 -1.7433309685 -5.6347701548
C 1.2438841575 -1.0208682792 -5.9252178172
H 1.2359279492 -1.1469601869 -7.0066358018
C 2.3557619853 -0.5194382117 -5.2885290594
H 3.2617921998 -0.2568864046 -5.8233209747
C 2.3812893553 -0.3896010291 -3.8618010374
H 5.5839003726 -0.3800800474 1.4458936575
C 5.1694435115 -0.2843018736 0.4460952988
C 3.7951114476 -0.4024400998 0.2338826694
N 3.202231319 -0.2819614299 -0.9704432777
C 3.9884758897 -0.0431478578 -2.0755106319
C 5.3984607978 0.1480839183 -1.9039817976
H 5.9797090367 0.3517634435 -2.7964756125
C 5.9779501785 0.0075928488 -0.66430474
H 7.0533500273 0.1240999752 -0.5404180719
N -0.9669580684 -1.5222978849 -3.0284732369
H -1.608559871 -2.0907602971 -3.565671503
N 3.5643874406 -0.0074738766 -3.3501556807
N 2.9848073189 -0.7061327038 1.3523112698
N -0.724786781 1.9243011913 0.1621723848
Co 1.0914002259 -0.3465172632 -1.0560467256
H 3.5386502861 -1.0287873027 2.1350241481
C -1.2782970925 3.2423403443 0.4210061464
H -1.6581963892 3.6512818104 -0.5209239903
H -0.4773047321 3.8886036171 0.7945924311
H -2.1024890691 3.265368608 1.1569868155
C 0.8531150286 -2.3963056679 -0.4659669098
O -0.0486535524 -2.4370204268 0.3713034968
O 1.6299554719 -3.1467310739 -1.0438757419
Listing S35. Coordinates of 2
(I)
-CO2, deprotonated.
214
H 2.3520644652 -0.5242640274 3.8393641855
C 1.696445395 -0.0060962016 3.1460516567
C 0.723711961 0.8897264752 3.5942318912
H 0.5816051873 1.0686256047 4.6556708543
C -0.05215086 1.5621736234 2.6491912706
H -0.8170735922 2.2632161425 2.960832051
C 0.1560116085 1.310237199 1.2936054839
N 1.0679443141 0.4036511427 0.8451527244
C 1.8300382353 -0.2195842973 1.7745435924
C -1.4013600412 1.1415016289 -0.5104933113
C -2.7902933284 1.2639376522 -0.5210323945
H -3.2766329058 1.9937861709 0.1149740702
C -3.5419104383 0.4263414016 -1.3462838737
H -4.6246799263 0.5020294144 -1.3731525753
C -2.8717074673 -0.4999753977 -2.1475894543
H -3.4077126608 -1.1469454827 -2.835452084
C -1.4818160523 -0.5761821047 -2.0649915531
N -0.7390031615 0.2095092972 -1.2501600217
N 1.2815692003 -0.388799674 -2.937703012
C 0.3486361102 -1.1187888 -3.5931110331
C 0.4649970835 -1.488928863 -4.9325878226
H -0.3277814098 -2.0605754328 -5.4055641981
C 1.6024018497 -1.0965987454 -5.6407998649
H 1.7331955839 -1.380248984 -6.6806676199
C 2.5608195829 -0.3191337497 -4.9894747051
H 3.4561481911 0.0024864228 -5.5077991324
C 2.3623160792 0.0279319625 -3.6535529148
H 5.4276102392 -1.4390381029 1.2686394911
C 5.0295738718 -0.9962268375 0.3606454947
C 3.6595714098 -0.7625706466 0.2460360778
N 3.0887370254 -0.194825006 -0.8422599599
C 3.9185996104 0.195659742 -1.8489288946
C 5.2952806917 -0.0237270836 -1.8183529919
H 5.9113554567 0.2677291274 -2.6604617636
C 5.8627817307 -0.6361649834 -0.7002483331
H 6.9321375119 -0.8178223284 -0.6516902408
N -0.7854387732 -1.4885501351 -2.8637917935
H -1.390667209 -2.1287927656 -3.3613222215
N 3.2843216616 0.8366772809 -2.9426885902
N 2.8035797814 -1.1033749433 1.2979964803
N -0.57915478 1.9802579955 0.2836087767
Co 1.1616155173 -0.0964910367 -1.0251019381
H 3.2606655598 -1.6290359437 2.0318812661
C -1.0970015709 3.3037387476 0.6070333045
H -1.4414500961 3.7771935293 -0.3162904356
H -0.2836643214 3.9015480454 1.0271112491
H -1.9317024302 3.3018523209 1.3268304516
C 4.0874319633 1.769970145 -3.7225701034
H 3.421479843 2.3365236546 -4.3789640559
H 4.8625101187 1.2934764244 -4.344632106
H 4.5784883574 2.4642124374 -3.0353025536
C 0.8912948351 -2.2093737164 -0.5990793693
O -0.0219740125 -2.3494227215 0.1998515539
O 1.704185005 -2.8591355777 -1.2387010042
Listing S36. Coordinates of 3
(I)
-CO2.
215
H 2.2754181286 -0.5409027791 3.8912907883
C 1.6373769355 -0.0056224583 3.1969493354
C 0.6310154134 0.8344887403 3.6105774851
H 0.4208115017 0.9674875855 4.6703757521
C -0.1194038107 1.5386122265 2.6513268637
H -0.9180301952 2.2087560975 2.9460559825
C 0.1512861611 1.3017036381 1.3074422974
N 1.1072800712 0.4481569854 0.8768395764
C 1.9326746515 -0.1467894598 1.8074875536
C -1.4027104015 1.137810387 -0.5256455572
C -2.7859060461 1.286639754 -0.586845386
H -3.2752104784 2.0297033387 0.0332372709
C -3.5388954439 0.4589728626 -1.4277729792
H -4.619638802 0.5511406575 -1.4833414786
C -2.8462633475 -0.4917861317 -2.2023623641
H -3.3633371697 -1.1352790435 -2.9091964536
C -1.4676953455 -0.6036065736 -2.0562639453
N -0.7246174532 0.1767415662 -1.2323656794
N 1.2849284763 -0.4160367023 -2.9117045986
C 0.345799926 -1.1394500228 -3.5707348554
C 0.4129834117 -1.4554634888 -4.9236358102
H -0.3986269778 -2.0125949391 -5.38396663
C 1.5358192135 -1.0403466788 -5.665375221
H 1.6448727187 -1.2999005255 -6.7143683682
C 2.5056202693 -0.2761384147 -5.0062768565
H 3.3908589084 0.0607540487 -5.534358809
C 2.3466283057 0.0307065403 -3.6571821219
H 5.4779567828 -1.4947833099 1.2138098316
C 5.0829863823 -1.0305021483 0.3170518564
C 3.7014372 -0.671711664 0.3298623788
N 3.1276205557 -0.1498958919 -0.8103764023
C 3.9287838542 0.1818084068 -1.8476984735
C 5.2965469329 -0.0708244024 -1.8743641187
H 5.8904222177 0.184803746 -2.743625096
C 5.8694503709 -0.724137604 -0.7679758081
H 6.9297188489 -0.9708300482 -0.7709715576
N -0.7554234927 -1.5547651552 -2.8048662568
H -1.3677861487 -2.1757693529 -3.3185675062
N 3.2842107797 0.8217749112 -2.9495505141
N 3.0664073769 -0.7994973674 1.5057308826
N -0.591485169 1.9678152492 0.2860251376
Co 1.18775623 -0.1011500812 -0.9917848865
C -1.1130597483 3.2838054396 0.6126089655
H -1.4399374552 3.768325329 -0.3127873979
H -0.3108051211 3.8776327805 1.0602814989
H -1.9656744843 3.2793671094 1.3150690113
C 4.0903314547 1.7448753795 -3.7297321336
H 3.425307487 2.3302270763 -4.3724360975
H 4.8489677175 1.2633886264 -4.3723441682
H 4.6093952474 2.4220826194 -3.0451313596
C 0.9745757111 -2.1533212438 -0.5227840882
O 0.0741198222 -2.3132843401 0.2934575412
O 1.7904680264 -2.8208212742 -1.14848703
Listing S37. Coordinates of 3
(I)
-CO2, deprotonated.
216
H 2.5535259291 -0.2939791081 3.7102495123
C 1.8400947948 0.1664195892 3.0374007515
C 0.9115150269 1.0967797571 3.5099818471
H 0.8773913821 1.3596162444 4.5629310557
C 0.0220105443 1.6758798409 2.6012951333
H -0.7359134485 2.3746741999 2.9341641093
C 0.1090379588 1.3300911551 1.2542415919
N 1.0119259186 0.4286104244 0.7813892981
C 1.8488700255 -0.1546410119 1.6819839729
C -1.4973047625 0.9736923133 -0.4925739534
C -2.8913061755 1.0058215247 -0.5397124899
H -3.4347750473 1.7259750622 0.0600020063
C -3.5687524767 0.0958535211 -1.3529823555
H -4.6527154088 0.1067883454 -1.4138825747
C -2.8216029735 -0.8224169725 -2.0928402777
H -3.2998167117 -1.5299931587 -2.7639051805
C -1.4336425724 -0.806924618 -1.9745565097
N -0.7599266972 0.0630089255 -1.1884592939
N 1.3210677852 -0.4906434559 -2.9657452963
C 0.3782247503 -1.2717320252 -3.5406276672
C 0.3982307798 -1.6286883011 -4.8895070709
H -0.4053031981 -2.2318602143 -5.3012555386
C 1.4462990168 -1.1746761337 -5.6891318511
H 1.4893055841 -1.4319342659 -6.7431789802
C 2.4391717094 -0.3877362613 -5.1091284783
H 3.2892648998 -0.0349613279 -5.6847834618
C 2.3404180462 -0.0697759046 -3.7524186615
H 5.4386913884 -0.9273657135 1.3473130114
C 5.0347115824 -0.5806801034 0.4036337507
C 3.6587293367 -0.5972244272 0.18590388
N 3.0895648213 -0.1230607601 -0.9588184066
C 3.9271246699 0.3007688516 -1.9351400789
C 5.3128631411 0.3257678818 -1.8033914406
H 5.9289029148 0.6622753484 -2.6320155562
C 5.8808691589 -0.1036755643 -0.6003258633
H 6.9563932825 -0.0808725866 -0.4547095486
N -0.653471369 -1.7319749056 -2.7015958924
H -1.2383474359 -2.4094889704 -3.1770675874
N 3.3283308045 0.7021241797 -3.1389560858
H 3.9834566036 1.1098558598 -3.7936405544
N 2.748981031 -1.1092349275 1.1440522653
N -0.7711568116 1.8765693367 0.3009450149
Co 1.1740859614 0.0950141941 -1.116995265
C -1.3417040527 3.1919638216 0.5540504296
H -1.7371843813 3.5808152835 -0.3871747691
H -0.539288303 3.8532848714 0.8896621472
H -2.1454814756 3.1923816145 1.3082617253
C 3.2472632125 -2.1380370824 2.0474500081
H 3.7441088402 -2.9101362481 1.4538021684
H 2.3956827402 -2.5862868056 2.5665811219
H 3.9599517355 -1.7725066594 2.8048871002
C 1.2852300176 2.1780065336 -1.6474703859
O 0.5492482916 2.4013009686 -2.6002574527
O 2.0585796154 2.759277865 -0.8991033733
Listing S38. Coordinates of 4
(I)
-CO2.
217
H 2.6267239807 -0.2594047952 3.6102920467
C 1.9051711043 0.2240162693 2.960497802
C 1.0601750472 1.2288638616 3.4483042074
H 1.0927309177 1.5286778888 4.4921215908
C 0.1441405863 1.8170052459 2.5591049896
H -0.5660909473 2.5582211602 2.9068591946
C 0.1271419583 1.4052831526 1.2298286567
N 0.9700498912 0.4504814302 0.7362507198
C 1.8149507082 -0.1508152425 1.6238882289
C -1.5216344769 0.9710736484 -0.4682460191
C -2.9049100005 0.8849036148 -0.3399727163
H -3.4319426967 1.5284588748 0.3548158768
C -3.5793452983 -0.0938630655 -1.0893558018
H -4.6580068529 -0.2064493365 -0.9948674581
C -2.8645921312 -0.8968446678 -1.9474156832
H -3.3367217741 -1.6388631822 -2.5819001921
C -1.4557457116 -0.7170295981 -2.1039964376
N -0.79576531 0.1777143434 -1.2910822733
N 1.2909154248 -0.3619292042 -3.0587516215
C 0.3094426482 -1.1259115041 -3.654246205
C 0.5165166201 -1.6316142302 -4.9742530951
H -0.2744504224 -2.2437807253 -5.3926129799
C 1.635359599 -1.2767728267 -5.6929502159
H 1.7736166471 -1.6311425614 -6.7128645784
C 2.6021452046 -0.4545725224 -5.0956247258
H 3.5166705897 -0.1771390573 -5.6116092648
C 2.3896916813 -0.0470969125 -3.7795738286
H 5.3188740533 -0.9940428 1.3812640562
C 4.9550303191 -0.612355272 0.4333190121
C 3.5931409604 -0.6341794301 0.1573406078
N 3.0551989362 -0.1224389628 -0.995334655
C 3.9365853456 0.3266537613 -1.9285294789
C 5.3130487069 0.3594880258 -1.739677222
H 5.9565268168 0.7115662676 -2.5420696801
C 5.8467760362 -0.1014775362 -0.5213808177
H 6.9174797782 -0.0912954931 -0.3393398219
N -0.8852130192 -1.4065724999 -3.1060661944
N 3.3777883309 0.7291382584 -3.1466284335
H 4.0725902976 1.0723451618 -3.7970996659
N 2.6310292415 -1.1712978124 1.0583546916
N -0.8004590676 1.9113273892 0.3106148987
Co 1.1406160934 0.1988357489 -1.1980605857
C -1.4160702031 3.1982308593 0.5730076072
H -1.895467967 3.5438973511 -0.3457345684
H -0.6284876372 3.9086236785 0.8405809815
H -2.1688676804 3.181254872 1.3816381718
C 3.0756976865 -2.2285675504 1.9458873809
H 3.5421271523 -3.0146867462 1.3431852405
H 2.2017402017 -2.6411803562 2.4604273525
H 3.8049330776 -1.9123602897 2.7142945945
C 1.2982243005 2.2345465194 -1.6401661965
O 0.5856239485 2.5444480817 -2.5923374908
O 2.0750673042 2.7902287157 -0.8642800012
Listing S39. Coordinates of 4
(I)
-CO2, deprotonated.
218
H 2.4501869394 -0.1291535457 3.7055520796
C 1.7652338576 0.3131592915 2.9922973721
C 0.8158404036 1.2533835369 3.3973062975
H 0.729693282 1.5383098769 4.4416133635
C -0.0172696429 1.8252891323 2.4337653306
H -0.775886447 2.5451795065 2.7162040622
C 0.1279148456 1.4439260591 1.1011016267
N 1.030769852 0.511090973 0.6985013901
C 1.8354865231 -0.0413933394 1.645359108
C -1.4849246843 1.0833987749 -0.638511445
C -2.8770573049 1.1641838629 -0.6274064179
H -3.3739318656 1.9177339219 -0.0284294679
C -3.6178952154 0.2539986514 -1.383263893
H -4.7028777823 0.2952703678 -1.3898860595
C -2.9371293377 -0.6989460453 -2.1424609033
H -3.4675187551 -1.4003686453 -2.7793776495
C -1.5439939877 -0.7294895246 -2.0849311536
N -0.8128131062 0.1235942022 -1.3303933081
N 1.195190355 -0.5013484325 -3.0208740473
C 0.277230846 -1.2974198223 -3.6167085546
C 0.3859903293 -1.7363648347 -4.9360520497
H -0.3915273839 -2.3623049913 -5.3635001761
C 1.4957687823 -1.3405052329 -5.6840700283
H 1.6217064512 -1.6774299441 -6.708557773
C 2.4331740695 -0.4897457197 -5.095815491
H 3.3050847703 -0.1617912939 -5.6487618686
C 2.2441764133 -0.0777165373 -3.7769651712
H 5.4514520391 -1.0619179474 1.1805192415
C 5.0123794816 -0.69785779 0.2595323589
C 3.6266570222 -0.5990885105 0.1378257819
N 3.0211438585 -0.1087762493 -0.9769659829
C 3.8160298858 0.2947551984 -2.0031106459
C 5.2056075803 0.1965427617 -1.962704721
H 5.7991764526 0.4941641618 -2.818571936
C 5.8168252378 -0.3055988535 -0.8121693927
H 6.8980583665 -0.3850305465 -0.7505835837
N -0.8314934434 -1.6626521084 -2.845744607
H -1.4221835755 -2.3516785371 -3.2930703842
N 3.1370484475 0.8152044872 -3.1344696797
N 2.7743726108 -0.9821654448 1.188034582
N -0.6741990849 2.0020069901 0.0731102928
Co 1.0962446312 -0.1096669534 -1.1292825263
C -1.2295900863 3.3287749111 0.3095242222
H -1.6251271728 3.7133341447 -0.6342655214
H -0.4249760414 3.9872041545 0.6477635111
H -2.0366181028 3.3554544588 1.0595892098
C 3.8755510437 1.7391366772 -3.9862996954
H 3.1713058219 2.2191954148 -4.6708478986
H 4.6720465157 1.2671331986 -4.5841825754
H 4.3302657883 2.5065352303 -3.3541583544
C 3.223857063 -2.019099054 2.1063763126
H 3.6663631208 -2.827455372 1.5195363069
H 2.3499889883 -2.4139851331 2.6297790014
H 3.9597369038 -1.6694425215 2.8485695105
C 0.9183473652 -2.1856023764 -0.5746005893
O 0.0298814981 -2.3187984409 0.2562764073
O 1.741265577 -2.8524661985 -1.1873338177
Listing S40. Coordinates of 5
(I)
-CO2.
219
H 2.5488015396 -0.0987370084 3.6538422767
C 1.8433905922 0.3462337067 2.960568202
C 0.9369678338 1.3323782678 3.3824705947
H 0.8913395788 1.6463908183 4.421407573
C 0.0776958195 1.8905989865 2.4215971994
H -0.6576178981 2.6334544484 2.7091781047
C 0.1502022458 1.4578642742 1.1018281242
N 1.0157496152 0.4847185351 0.6852585824
C 1.835653677 -0.0610435408 1.6314177973
C -1.5000754996 1.0671262657 -0.626848928
C -2.8872862811 1.1315209653 -0.5425275529
H -3.3705569817 1.8548402873 0.1032001315
C -3.6382256377 0.1916331147 -1.272351597
H -4.7243848134 0.1903779542 -1.1999705676
C -2.990681642 -0.7080674688 -2.0854403827
H -3.5199288787 -1.4253165496 -2.7028778088
C -1.5682663174 -0.6800477078 -2.1999312332
N -0.8426400272 0.1582049549 -1.3807060595
N 1.1667478494 -0.4657122114 -3.0693924537
C 0.192511952 -1.2250839761 -3.6815425175
C 0.4430354037 -1.768557675 -4.9773290453
H -0.3219284811 -2.4121985595 -5.3972421657
C 1.5790310727 -1.4181811066 -5.6678106406
H 1.7624772886 -1.8097601729 -6.6668126466
C 2.5011445005 -0.5320729939 -5.0810479756
H 3.4028371577 -0.2349902908 -5.602927866
C 2.2526112016 -0.0947939373 -3.7838067779
H 5.4011998851 -1.00886518 1.2490285128
C 4.9845843269 -0.6508952075 0.3138888684
C 3.6052996661 -0.6193792109 0.1420169921
N 3.0016395077 -0.1359491008 -0.9836081523
C 3.8205540168 0.3087226978 -1.9841828129
C 5.20805756 0.2746500493 -1.8967150208
H 5.8124765201 0.5970906152 -2.7369408174
C 5.8171650102 -0.21310599 -0.7288516786
H 6.8989636345 -0.2600626107 -0.6416075734
N -1.0332428947 -1.4341318153 -3.1740138022
N 3.1560562485 0.7995155898 -3.1339854165
N 2.7209734972 -1.0506482584 1.1533776583
N -0.6857757296 1.993313894 0.092785086
Co 1.0678099999 -0.1174577723 -1.1605436508
C -1.256766863 3.3072369434 0.3345708987
H -1.6973027695 3.6741083744 -0.5966611787
H -0.4543848582 3.9864367598 0.6393590001
H -2.0383658143 3.3300987195 1.1146666085
C 3.8989402661 1.7083368381 -3.9900781819
H 3.2058259197 2.1618503987 -4.7041166603
H 4.7165424479 1.234266243 -4.5617896704
H 4.3340789269 2.4966267508 -3.3678784146
C 3.1624465147 -2.0838559899 2.0657225408
H 3.6058119428 -2.8924557363 1.4775901336
H 2.285592646 -2.4726227599 2.5912243483
H 3.9025612255 -1.7447287547 2.8148661273
C 0.849819746 -2.1522237241 -0.6668707379
O -0.0482568222 -2.3050580953 0.1558159143
O 1.6613213727 -2.8372630478 -1.2823812877
Listing S41. Coordinates of 5
(I)
-CO2, deprotonated.
220
H 2.5562759232 -0.4265279911 3.6105412514
C 1.8361605199 0.0436734904 2.951926511
C 0.8866555948 0.9355998929 3.4547398329
H 0.8444916422 1.1554863437 4.5173451262
C -0.0117998117 1.5334753085 2.5694377871
H -0.784344009 2.202879977 2.9281800654
C 0.0854660807 1.243423999 1.2084713087
N 1.0095448944 0.3805096535 0.709281246
C 1.856815615 -0.2219672774 1.5835309426
C -1.5010117569 0.9503441755 -0.5807160473
C -2.8910564854 1.0056857046 -0.6832629728
H -3.4514240947 1.7182891655 -0.0902089347
C -3.5417707682 0.1206144987 -1.5443718651
H -4.6214584762 0.1521139073 -1.6564244586
C -2.7818383395 -0.8116597437 -2.2537533986
H -3.255585963 -1.503726265 -2.9393766301
C -1.3986913606 -0.8290841381 -2.0802755798
N -0.7523269221 0.0510927584 -1.272621514
N 1.3235332474 -0.4188072489 -3.0392274647
C 0.4099751422 -1.2430442356 -3.61509234
C 0.4295900406 -1.5508739362 -4.9746452011
H -0.3413283849 -2.1792724827 -5.4037578363
C 1.4456821397 -1.0237226296 -5.7742226641
H 1.4879506256 -1.2525594514 -6.8349306038
C 2.4098682752 -0.2038152427 -5.1855127758
H 3.2323550941 0.1943208157 -5.767424862
C 2.3118033788 0.0855037402 -3.824439523
H 5.4696143866 -1.06284838 1.1366882153
C 5.0475759074 -0.6627593793 0.2227907954
C 3.6654940121 -0.6228566049 0.0451045169
N 3.086005306 -0.0843398629 -1.0590117418
C 3.8990005209 0.3927369682 -2.0382426038
C 5.2901321201 0.3594827756 -1.940091572
H 5.901317456 0.7229999869 -2.7573298812
C 5.8747108558 -0.1634125102 -0.7853733486
H 6.9547835989 -0.1872279499 -0.6751585207
N -0.5753951409 -1.7724546086 -2.7448758857
N 3.2592692513 0.9023957106 -3.1818517843
N 2.7732037309 -1.1422952463 1.0163477267
N -0.7973910175 1.8154654664 0.2754349413
Co 1.1728625443 0.1129063717 -1.1928700943
C -1.3718162063 3.120802916 0.5709463274
H -1.7406350246 3.5518830611 -0.3626924239
H -0.5778361332 3.7650552432 0.9557121959
H -2.1953120068 3.0895199038 1.3026928557
C 3.9442967942 1.9207322355 -3.9659480322
H 3.2055148251 2.423920491 -4.5939376691
H 4.7487279415 1.5232699112 -4.6058511752
H 4.3671590231 2.6563665525 -3.2777446378
C -1.1947803054 -3.0333513891 -3.1340151693
H -0.4058230436 -3.7393032203 -3.4065143086
H -1.8940537276 -2.9514116985 -3.9818685744
H -1.7413637775 -3.4319106186 -2.2753095542
C 3.2811532728 -2.1950463203 1.887252227
H 3.7705232583 -2.9520885169 1.2687577973
H 2.4358603306 -2.6570255849 2.4041458536
H 4.0024694584 -1.8479306662 2.6448106102
C 1.2699419616 2.201958362 -1.6313459333
Listing S42. Coordinates of 6
(I)
-CO2.
O 0.5302012804 2.4751605067 -2.5700562623
O 2.0487167054 2.7617333057 -0.8676442895
221
H 2.741066364 -0.2738954067 3.8090599281
C 2.0204486208 0.1809484147 3.1373069656
C 1.0859185263 1.1042249571 3.5984390142
H 1.0505865519 1.3721137007 4.6499614634
C 0.1969844058 1.6738519443 2.6973192451
H -0.5657299226 2.3736938917 3.0229066236
C 0.2660353525 1.2896702173 1.3537565829
N 1.1923291832 0.425787406 0.8807586943
C 2.0486995902 -0.1164416999 1.7742649346
C -1.352188275 0.9701718301 -0.4531923662
C -2.7384626773 1.1008291306 -0.5867745689
H -3.2708824309 1.852285564 -0.012987151
C -3.4107241963 0.2235607074 -1.426419646
H -4.4878895063 0.2914914474 -1.5438817173
C -2.6864878051 -0.7456894324 -2.1149564235
H -3.1751322541 -1.4365655634 -2.7941168693
C -1.3004686417 -0.7802536458 -1.957249051
N -0.6279119922 0.0598925906 -1.1413757837
N 1.4774504705 -0.5343479153 -2.9255286337
C 0.5202527649 -1.295507502 -3.4988451789
C 0.5391759087 -1.6605525856 -4.8455277106
H -0.2627823087 -2.2643830923 -5.2574551915
C 1.5740016466 -1.1891660317 -5.6485453196
H 1.6062038189 -1.4365743372 -6.7051610583
C 2.5651467005 -0.4007054477 -5.0805947653
H 3.4023576031 -0.0372803561 -5.6674540086
C 2.4942096885 -0.1178675594 -3.7124593645
H 5.6603163451 -1.0993827112 1.3369942084
C 5.2514833179 -0.7338280703 0.4007195985
C 3.8700875691 -0.6329105199 0.2312427877
N 3.2951449378 -0.1715325539 -0.9009602373
C 4.117077153 0.1981187112 -1.9089579836
C 5.5120484359 0.1683356305 -1.8052281189
H 6.1254869191 0.4788617523 -2.644730994
C 6.0818168962 -0.3106197234 -0.6336200772
H 7.1611575608 -0.357980562 -0.5263317859
N -0.5418057575 -1.7135288344 -2.6814224426
H -1.1311071259 -2.3911154565 -3.1514805009
N 3.5308320714 0.5910606716 -3.1090726066
H 4.1920294207 0.975519648 -3.7726415961
N 3.0133610814 -1.0072411577 1.2782739653
N -0.6758559384 1.7825797917 0.4544599992
H -1.2537098463 2.5187663775 0.8410682529
Co 1.3460532837 0.1031234303 -1.0604088795
H 3.5162147682 -1.4700351363 2.0267953148
C 1.4471838123 2.0848795087 -1.6017132808
O 0.8304089199 2.6205636898 -2.5121734446
O 2.3075128518 2.8762574485 -0.8458254551
H 2.2563061376 3.7870468387 -1.2111453675
Listing S43. Coordinates of 1
(II)
-CO2H.
222
H 2.7124292424 -0.3255867195 3.718592426
C 1.99529745 0.1586065049 3.0633943672
C 1.0988171876 1.1121331981 3.5460409926
H 1.0888419514 1.3732156665 4.6003885914
C 0.216338635 1.7144681286 2.6641155818
H -0.5200816652 2.4361875531 3.003184288
C 0.2460249901 1.3335188152 1.3128382683
N 1.1421826881 0.4470525086 0.8195588927
C 1.988323362 -0.1282017688 1.6978608368
C -1.3909954736 0.9931724914 -0.4547374688
C -2.7781717395 1.0182726796 -0.4118540771
H -3.2939445314 1.6965751824 0.2606468106
C -3.475666918 0.0944688742 -1.2075552157
H -4.5620043771 0.0634274652 -1.1831836005
C -2.7670015628 -0.7656044044 -2.0109225746
H -3.2494972082 -1.4816517467 -2.6655402543
C -1.3437019087 -0.6803911242 -2.0929031702
N -0.6645015139 0.17909256 -1.2516543769
N 1.4156152144 -0.4102878348 -3.0135051006
C 0.4297384213 -1.1855410054 -3.5923019551
C 0.6433846118 -1.7394416208 -4.8913207006
H -0.1427958863 -2.3725176105 -5.2852757286
C 1.7509353426 -1.3936435395 -5.6269128472
H 1.8884540369 -1.7746655662 -6.6356889119
C 2.7102763285 -0.5391874358 -5.0587380396
H 3.614938451 -0.2624749649 -5.5910279258
C 2.5040669725 -0.1097027543 -3.7550016315
H 5.5620690794 -1.1357132115 1.2999885855
C 5.1771140685 -0.7433706399 0.3640980868
C 3.8004350122 -0.6408408874 0.1605430419
N 3.2482106206 -0.1466052682 -0.9660181432
C 4.0923804652 0.2477116208 -1.9481710798
C 5.4892298691 0.22434286 -1.8063795293
H 6.1185228006 0.5604406243 -2.6243838423
C 6.0322832999 -0.2843553967 -0.6376473434
H 7.1093900254 -0.3319215508 -0.505324527
N -0.7744036895 -1.4182040523 -3.0546943826
N 3.5232872934 0.6544685797 -3.1379400894
H 4.2017585634 0.9973286725 -3.8063999992
N 2.9180521883 -1.0479915685 1.1783286025
N -0.6840834061 1.8425140704 0.4294465038
H -1.2820398766 2.5463706424 0.843808041
Co 1.2937283318 0.2118559041 -1.1576764018
H 3.4139166432 -1.5257052108 1.9218645911
C 1.5394209457 2.2262123741 -1.5370744339
O 1.0045738557 2.9075857161 -2.3990705956
O 2.4459632882 2.8930123514 -0.6852623416
H 2.4582585206 3.8289008381 -0.9839722201
Listing S44. Coordinates of 1
(II)
-CO2H, deprotonated.
223
H 2.4314566587 -0.2226437942 3.719660369
C 1.7398654485 0.2394701216 3.02254629
C 0.7614994715 1.1222071567 3.4516533939
H 0.6469725632 1.3447733864 4.5082310821
C -0.0678913057 1.7329532521 2.5111355569
H -0.8400838779 2.4233072247 2.8246284831
C 0.084606715 1.4044430963 1.1640390576
N 1.0210773044 0.5233808436 0.733245747
C 1.8540697298 -0.0120709616 1.6501587831
C -1.5348513452 1.0731465588 -0.5838976367
C -2.9276905296 1.1505379757 -0.5784311391
H -3.4343895988 1.8971572474 0.0189154397
C -3.6572279834 0.2215101535 -1.3199316127
H -4.7427094703 0.2479866506 -1.313941131
C -2.9825715409 -0.7263466842 -2.0728424035
H -3.5141973431 -1.4387712741 -2.6954455641
C -1.5827786332 -0.7184418226 -2.0541147239
N -0.8625469218 0.1353157915 -1.2963812354
N 1.1486972607 -0.4428763928 -3.0694024855
C 0.2084462474 -1.2206765864 -3.6503288466
C 0.2762422745 -1.6260587253 -4.9876419132
H -0.5043258458 -2.253543493 -5.4052667552
C 1.3319156571 -1.1729241188 -5.7667183178
H 1.4077579386 -1.4613792314 -6.8106318449
C 2.292560807 -0.3439530941 -5.1935483192
H 3.1425371413 0.0123581997 -5.7662436629
C 2.1722696389 -0.0196011669 -3.8417136217
H 5.5256550693 -0.9695594548 1.0919302453
C 5.0696167884 -0.6049888989 0.1773522323
C 3.6783537872 -0.4908014985 0.0857197437
N 3.048696761 -0.0445630606 -1.0240336533
C 3.8173500993 0.3324028169 -2.0683382852
C 5.2119850204 0.2883030621 -2.0438350268
H 5.7825693073 0.5923204577 -2.9152775684
C 5.84213362 -0.2017769223 -0.9033163739
H 6.9249288194 -0.268037318 -0.8597946639
N -0.8869499279 -1.5993876452 -2.8779443092
H -1.4798947887 -2.2846214722 -3.3295417636
N 3.1561215229 0.7713790559 -3.2264069046
H 3.803896469 1.1570471318 -3.9038512688
N 2.8932400658 -0.8164874846 1.1895890821
N -0.7504841061 1.9695010694 0.1748370267
Co 1.0810884751 -0.1064605652 -1.1278949283
H 3.4110389798 -1.2712639742 1.93137253
C -1.3292252873 3.285855464 0.4616695411
H -1.7262674807 3.6988336029 -0.4680695616
H -0.5336373355 3.9425827207 0.8199470106
H -2.1336469074 3.2666912137 1.2102385344
C 1.0095740637 -2.1152748848 -0.6777332861
O 1.705471511 -2.9938607773 -1.1677014874
O 0.0704250594 -2.4890945608 0.2794433557
H 0.1464299534 -3.462228391 0.3927567902
Listing S45. Coordinates of 2
(II)
-CO2H.
224
H 2.3820753367 -0.2949675755 3.7341395069
C 1.7169651036 0.1791834839 3.0190636161
C 0.7450161166 1.0794691388 3.4190550861
H 0.6060702737 1.3081819094 4.4719780986
C -0.0461734886 1.7057912884 2.4527909074
H -0.813188082 2.413587642 2.7400802285
C 0.1409743783 1.3669169882 1.1128260624
N 1.0661213892 0.4667210942 0.7068958957
C 1.871453669 -0.0765032088 1.6467193212
C -1.4721599567 1.0354169251 -0.6288600929
C -2.8633092219 1.1297954435 -0.5925199116
H -3.3481976284 1.8979619803 -0.0039125433
C -3.6176682469 0.1863800488 -1.2943045767
H -4.7030787752 0.2235351742 -1.2665821653
C -2.9676440532 -0.7835139483 -2.0372396418
H -3.5160897732 -1.5071226719 -2.6323194957
C -1.5632834727 -0.7859210137 -2.056103053
N -0.8205656233 0.0758782857 -1.3261476094
N 1.2075782431 -0.5838259972 -3.071999829
C 0.196602734 -1.2431180128 -3.6786131075
C 0.1289758931 -1.4897694779 -5.0431841408
H -0.7194091011 -2.0204396135 -5.4638569676
C 1.1524656105 -0.9716352072 -5.8539364903
H 1.1235459967 -1.1204596348 -6.9304119313
C 2.184646013 -0.2772314765 -5.2700227921
H 3.0146871218 0.1211361421 -5.841437015
C 2.2570059831 -0.137689238 -3.850753451
H 5.5164099387 -0.7019576629 1.2560084335
C 5.0824157572 -0.4411363741 0.295816867
C 3.7088474578 -0.5053542575 0.1049730741
N 3.0838152763 -0.1906890114 -1.0506129408
C 3.8566657545 0.2024146352 -2.1254127698
C 5.2623445668 0.3825085975 -1.9485110299
H 5.8211854879 0.7286702564 -2.8099253604
C 5.8697049792 0.0346976659 -0.7659631301
H 6.9466166793 0.1252132253 -0.6482350075
N -0.8827842184 -1.6698493003 -2.8693552177
H -1.490758413 -2.3209941488 -3.3497815977
N 3.4001390489 0.3727673165 -3.3732904948
N 2.8998047663 -0.883420379 1.2027959023
N -0.6594089387 1.9398585567 0.0954146523
Co 1.1305345839 -0.2476331096 -1.1456409795
H 3.4379899575 -1.295489629 1.9544659077
C -1.2064765604 3.2703089686 0.3490454464
H -1.5907601754 3.6714321502 -0.5919079387
H -0.3971918835 3.9163104854 0.6978994599
H -2.0164122815 3.2927562718 1.0943794492
C 0.9101489457 -2.2168807577 -0.5611986739
O 1.526466575 -3.1966503444 -0.9528587991
O -0.081199902 -2.4494529796 0.4150549627
H -0.0682038414 -3.4164486434 0.5882358762
Listing S46. Coordinates of 2
(II)
-CO2H, deprotonated.
225
H 2.4106132319 -0.1633123277 3.7949790524
C 1.7320633629 0.2957827767 3.0832166082
C 0.7580131008 1.194585401 3.4884759779
H 0.6351144064 1.4341377527 4.5404016026
C -0.0579732545 1.7978582388 2.5313337703
H -0.8285071279 2.4974889147 2.8278766444
C 0.1061485403 1.4494137951 1.1905130629
N 1.0418950754 0.5566793218 0.7834665831
C 1.8574216591 0.021307192 1.7160573588
C -1.4861672439 1.1068234587 -0.5855260106
C -2.8782839779 1.1918417812 -0.6145082733
H -3.3957641907 1.9455257117 -0.0355698596
C -3.5942911831 0.2608490546 -1.3670114142
H -4.6793832133 0.2943680667 -1.3889393438
C -2.9076298973 -0.6992645145 -2.0932383073
H -3.4288686974 -1.4151258606 -2.7206369954
C -1.5086238521 -0.7017124697 -2.0382016481
N -0.8035439878 0.1593801435 -1.2745636879
N 1.2419170143 -0.4527155715 -2.9929211664
C 0.3280303513 -1.2604264744 -3.5693714017
C 0.4482567497 -1.729159922 -4.8829076776
H -0.3106814207 -2.3837587937 -5.2991561738
C 1.5295439628 -1.303424622 -5.6379159531
H 1.6532232186 -1.6448129689 -6.6612185211
C 2.4551704934 -0.4255939804 -5.0739473458
H 3.3110102738 -0.0878766169 -5.6436250756
C 2.2860050577 -0.0305527022 -3.7468280981
H 5.5060773551 -1.1067621187 1.1885252304
C 5.0724914587 -0.7133696317 0.2747864143
C 3.6883856313 -0.5288450668 0.1766088891
N 3.0894915008 -0.0508794604 -0.9337726739
C 3.875907777 0.320495776 -1.9733614581
C 5.2652187547 0.1997460173 -1.9372166221
H 5.8650574871 0.4857541308 -2.7912592782
C 5.864237856 -0.3432685323 -0.8007556801
H 6.9418752839 -0.4693890535 -0.7584601588
N -0.7980352938 -1.6044804376 -2.8247517688
H -1.3821700922 -2.2987596694 -3.2738677731
N 3.2143068959 0.8270243442 -3.1143392319
N 2.8843580574 -0.8113567632 1.2790902923
N -0.7140561748 2.0059260512 0.183626549
Co 1.1312832333 -0.0846553618 -1.0676520282
H 3.3797992331 -1.272461731 2.0320489227
C -1.2951990603 3.3253958567 0.4500862762
H -1.6762381381 3.7317118932 -0.4892414528
H -0.5048792558 3.9840397141 0.8164686521
H -2.1119795806 3.313081165 1.1853245435
C 3.9719610869 1.7409396544 -3.9747518181
H 3.2735090044 2.2366189313 -4.6522584303
H 4.7520003809 1.2486091189 -4.5722663682
H 4.4408957889 2.5000036612 -3.3450012258
C 1.0276147715 -2.0902722681 -0.5884425994
O 0.0606977588 -2.435649355 0.3520909168
O 1.722675847 -2.9867447624 -1.0460556801
H 0.1216439809 -3.4074968869 0.4836038542
Listing S47. Coordinates of 3
(II)
-CO2H.
226
H 2.3389210936 -0.1984873188 3.815484131
C 1.6687937129 0.2803926414 3.1110021599
C 0.6377744235 1.094880222 3.5069174566
H 0.439948649 1.2651684686 4.5623736948
C -0.1618840258 1.7246284137 2.5326715886
H -0.9805299174 2.3730063876 2.8183132284
C 0.0979695982 1.4459116188 1.1995792367
N 1.0875520946 0.6232893203 0.7856984333
C 1.9492148034 0.0933029305 1.7242223421
C -1.4790825774 1.1324497113 -0.5929108709
C -2.8737171666 1.2277617142 -0.6598613521
H -3.3959876986 1.9927962669 -0.1000338207
C -3.5799273276 0.2894355253 -1.4090439001
H -4.6646726539 0.3286138089 -1.4544069282
C -2.8828783036 -0.6905576918 -2.1012211647
H -3.3925745194 -1.4149300022 -2.7289027899
C -1.4852793708 -0.700163919 -2.0123528305
N -0.787624852 0.1676069226 -1.2528084213
N 1.2606349908 -0.4503832324 -2.974851413
C 0.348342708 -1.2671505445 -3.5360148226
C 0.4427001493 -1.7313231218 -4.8538652966
H -0.319791983 -2.3928120607 -5.253285947
C 1.502420912 -1.2899005238 -5.6326308379
H 1.6085845262 -1.628682602 -6.6593618182
C 2.4280779284 -0.4038881575 -5.0857707267
H 3.2721975785 -0.0580631211 -5.6683282963
C 2.286826378 -0.0155625787 -3.7490481873
H 5.5334381377 -1.1229210485 1.1450921587
C 5.1097063976 -0.7217053844 0.2318602202
C 3.7148579409 -0.4232350416 0.2445667631
N 3.110837807 0.0254999027 -0.911852507
C 3.8849485279 0.3203883971 -1.980223547
C 5.2574694914 0.1249676999 -2.0110295267
H 5.8340835261 0.3538398206 -2.8981880378
C 5.8703147818 -0.4376515649 -0.8746742476
H 6.9391408505 -0.636727064 -0.8783787999
N -0.7644313919 -1.6197904631 -2.7724411396
H -1.3464996375 -2.3191024591 -3.214971544
N 3.2063536887 0.8423862876 -3.1294947994
N 3.093682477 -0.5356623528 1.4272663931
N -0.7157433568 2.0247210722 0.1710752681
Co 1.1663258694 -0.0457432024 -1.041797044
C -1.2999841963 3.3324611568 0.4536113762
H -1.6692176947 3.7623601196 -0.4817188258
H -0.5148317378 3.979630214 0.8506050098
H -2.1284089492 3.3104845114 1.1786009185
C 3.9691315406 1.7386032662 -3.9934526167
H 3.2768077252 2.2475761611 -4.6698368846
H 4.7410751406 1.2370515936 -4.5975365795
H 4.4583002765 2.4862516368 -3.3651661313
C 1.0511600901 -2.0654769078 -0.5705541981
O 0.1255949073 -2.4059644975 0.4190373803
O 1.7059723956 -2.9820008043 -1.0540863499
H 0.2257662416 -3.3718501271 0.5691044437
Listing S48. Coordinates of 3
(II)
-CO2H, deprotonated.
227
H 2.4409314648 -0.4352822971 3.7411158875
C 1.7594383057 0.059671043 3.0616418523
C 0.870412266 1.0256620581 3.5256670278
H 0.8382719564 1.2764812496 4.5817822898
C 0.0204682959 1.65985245 2.6307943653
H -0.7031581117 2.3868387621 2.9755720849
C 0.0796230984 1.303015746 1.27794366
N 0.9669785004 0.3926135955 0.8116791732
C 1.7873257195 -0.2225795913 1.6950313905
C -1.5319384254 0.9937421113 -0.4928308288
C -2.9276259486 1.0582385815 -0.5668440256
H -3.4729433282 1.7758508055 0.0325527162
C -3.6016030715 0.1547352838 -1.3811295365
H -4.6855726833 0.175238446 -1.4415513288
C -2.8743960656 -0.7739214694 -2.1165257089
H -3.3649328369 -1.475401935 -2.7836724183
C -1.4816043841 -0.7580097043 -2.013670742
N -0.8122917481 0.0948269411 -1.2115538888
N 1.2961903812 -0.4613161298 -2.9904594992
C 0.3449675811 -1.211548603 -3.5870152338
C 0.3823008954 -1.5510505504 -4.9402316784
H -0.414805464 -2.1442548498 -5.376383987
C 1.4350874666 -1.0734505705 -5.7166734855
H 1.483798391 -1.3049533775 -6.7763015668
C 2.4243205133 -0.3025073102 -5.1204303657
H 3.275024633 0.0606243076 -5.6878075677
C 2.3312975627 -0.0379620541 -3.7497459757
H 5.3919441276 -1.134698843 1.3286913906
C 4.9917519769 -0.738200491 0.4046506872
C 3.6137217439 -0.6832101006 0.1944301967
N 3.0756116174 -0.1673225381 -0.9371804343
C 3.9137191738 0.2617133424 -1.902675367
C 5.3049404491 0.2744872392 -1.7505736728
H 5.9379932726 0.6392883121 -2.5530059873
C 5.8428383677 -0.2298922551 -0.5766440404
H 6.9179844176 -0.2385191282 -0.4249883238
N -0.721887333 -1.649868955 -2.787336868
H -1.3070593086 -2.3193012223 -3.2735654398
N 3.3531433967 0.6641466222 -3.1142995553
N 2.7028695121 -1.1591581323 1.1633555884
N -0.8252467051 1.8508549275 0.3597577914
Co 1.1447084961 0.1234402764 -1.1216608171
C -1.3952073192 3.170013293 0.647321702
H -1.7980658858 3.5791077856 -0.2808574513
H -0.5893921879 3.8246661235 0.985041492
H -2.1897680817 3.1484643886 1.4058293425
C 3.1779600808 -2.2156779888 2.0620526741
H 3.6597762697 -2.9899617809 1.4612248102
H 2.3144853561 -2.6562771413 2.5649985464
H 3.8896346488 -1.8679485002 2.8240073779
C 1.3471094057 2.135710042 -1.516912716
O 0.6079336019 2.6125511131 -2.5986112262
O 2.0287069202 2.9426689935 -0.8985332021
H 4.0252423529 1.0682246487 -3.7548240108
H 0.8030266697 3.5723870304 -2.6777050972
Listing S49. Coordinates of 4
(II)
-CO2H.
228
H 2.4592914026 -0.3724598964 3.6634379738
C 1.7755440937 0.1346983136 2.9946335998
C 0.9488296225 1.1579943373 3.4581280959
H 0.9691929048 1.4441922382 4.5061535894
C 0.0908926315 1.7969321269 2.5769578224
H -0.5902478304 2.5637061953 2.9228154438
C 0.0735888407 1.3868502242 1.2333806426
N 0.9222010106 0.4382554902 0.7618617442
C 1.7384128982 -0.1850173363 1.6366198204
C -1.5596669841 0.9639726155 -0.4759470048
C -2.9376204717 0.8681543769 -0.3442710785
H -3.4715226508 1.5044142118 0.3509891228
C -3.6057788971 -0.1176680491 -1.0939434493
H -4.6810983927 -0.2417592571 -0.991584397
C -2.889586985 -0.9108900352 -1.9563319126
H -3.3574180049 -1.6592306574 -2.5855449174
C -1.4854093765 -0.7112405195 -2.1274227766
N -0.8299652242 0.18524529 -1.3093247167
N 1.2612434587 -0.3361011024 -3.0657345765
C 0.2736527116 -1.0742655891 -3.6873076157
C 0.4761550573 -1.5262275209 -5.0258778656
H -0.3143596836 -2.1243242771 -5.4634906831
C 1.5886781481 -1.1407713388 -5.7357337052
H 1.7204126045 -1.4497688241 -6.769675652
C 2.5626393559 -0.3468826575 -5.1087532235
H 3.4733111703 -0.0505461016 -5.61992475
C 2.3587721867 -0.0023293513 -3.7789838998
H 5.2840134214 -1.2591326093 1.3082909428
C 4.916330598 -0.8243892898 0.3877286872
C 3.5454193898 -0.716685514 0.1509339294
N 3.0408533925 -0.1580608016 -0.9736186982
C 3.910558298 0.2692625832 -1.9145259815
C 5.3023367305 0.2390410668 -1.7300604429
H 5.9590964476 0.6072325758 -2.5120523227
C 5.8025472411 -0.3154188183 -0.5644329763
H 6.8744674063 -0.3645613924 -0.3946126169
N -0.915255535 -1.373137534 -3.1429788382
N 3.3781606451 0.7145619446 -3.1103940499
N 2.5996257968 -1.1742365558 1.0972131917
N -0.8440954655 1.8965465911 0.3297203799
Co 1.1110624435 0.228721224 -1.2008745926
C -1.4706201646 3.1826644176 0.6100051199
H -1.9486671714 3.5340828394 -0.3060260637
H -0.6907431253 3.8968271968 0.8875656111
H -2.2259615163 3.143471726 1.410285554
C 3.0187801909 -2.2495157755 1.9926301128
H 3.4627104723 -3.0474126304 1.3922049874
H 2.1332716976 -2.6451976536 2.4956820653
H 3.7476817884 -1.9431469729 2.7587169416
C 1.4313143247 2.2552768585 -1.462848836
O 0.7731951218 2.8431843102 -2.5406158865
O 2.1196677859 3.0015856282 -0.7675641245
H 4.0780228872 1.0730192938 -3.7478268832
H 1.0271633018 3.7926243853 -2.5311708405
Listing S50. Coordinates of 4
(II)
-CO2H, deprotonated.
229
H 2.2579443966 -0.0350055954 3.7495129381
C 1.558424045 0.3424319062 3.0148248683
C 0.5677332615 1.2455259782 3.3747575815
H 0.4649099184 1.5609503447 4.4088553916
C -0.2894596124 1.7507806916 2.4005226002
H -1.0789899215 2.4417118791 2.6655812049
C -0.1374118128 1.3142270361 1.0830283359
N 0.8242542658 0.4326479547 0.7209423245
C 1.6708478088 -0.0331186647 1.6704698085
C -1.7264084853 0.7798711543 -0.6555138752
C -3.1213612542 0.7720061823 -0.6728942009
H -3.6834209068 1.5099583519 -0.1153954922
C -3.7795635842 -0.2291015001 -1.3880196444
H -4.8646609566 -0.2678974506 -1.3995333478
C -3.0379556772 -1.1641652679 -2.0933756468
H -3.5169605446 -1.930136936 -2.6947508746
C -1.6415839282 -1.0739745846 -2.0509492558
N -0.99185326 -0.1480032234 -1.3158197081
N 1.0859595383 -0.666646338 -3.0097033574
C 0.2276016247 -1.5413224586 -3.573044966
C 0.3821357487 -2.020474316 -4.8790461903
H -0.3302861179 -2.7297268697 -5.2878793674
C 1.4358965385 -1.5345368052 -5.6376139716
H 1.5855986067 -1.8830776942 -6.6550334893
C 2.2984896181 -0.586194734 -5.0874400589
H 3.1296622461 -0.1992750409 -5.6624783979
C 2.0982252628 -0.1806088821 -3.767539321
H 5.3728432759 -0.8742997574 1.202685163
C 4.9031395799 -0.542870739 0.2858061113
C 3.5076560789 -0.5141787174 0.1726596999
N 2.8870597181 -0.0929534015 -0.9547141252
C 3.6430536612 0.3441570613 -1.9886129955
C 5.0376859543 0.3694768239 -1.9330372301
H 5.6180927338 0.7073706322 -2.7815455534
C 5.6682830165 -0.0924362727 -0.7807744309
H 6.7523110623 -0.0958326944 -0.7157250204
N -0.8739604823 -1.9456718116 -2.820315612
N 2.9523857427 0.7602183679 -3.14970099
N 2.7001059146 -0.8874531451 1.2555037714
N -1.0057618352 1.7613993288 0.0619051903
Co 0.9470746064 -0.2673579712 -1.0985516026
C -1.6654967187 3.0552488783 0.2626606149
H -2.0865941122 3.3805595213 -0.6908879854
H -0.9135414884 3.783347648 0.5743786139
H -2.4681457712 3.0346860329 1.0131322163
C 3.6354541074 1.7155026808 -4.0274128985
H 2.9028560674 2.1345327675 -4.7204247509
H 4.4588903465 1.2770215201 -4.6083473322
H 4.033502031 2.526297225 -3.4135835082
C 3.2383197747 -1.8496460214 2.2210396085
H 3.7283751085 -2.6527017029 1.6673082476
H 2.4042494262 -2.2820310481 2.7766079399
H 3.9513481508 -1.4064220046 2.9297166374
C 0.9693564032 -2.2599784186 -0.5573043478
O 1.7470953716 -3.1200626258 -0.9490948119
O -0.0023126324 -2.6439963225 0.3660802601
H -1.4118284689 -2.6850862582 -3.2550140368
H 0.1173365592 -3.6064646937 0.5240392696
Listing S51. Coordinates of 5
(II)
-CO2H.
230
H 2.2832236789 -0.0232153199 3.7143260416
C 1.5764951712 0.3633157791 2.9906159159
C 0.6099844301 1.2916948283 3.3577653348
H 0.5288472872 1.6185858497 4.3908486777
C -0.2514959717 1.8022653587 2.3919646258
H -1.0279558266 2.506762573 2.660968299
C -0.1351727407 1.3457470611 1.0729920556
N 0.8081843983 0.4437455305 0.7043195767
C 1.6559584602 -0.0258560481 1.6478310154
C -1.7339256714 0.7751280392 -0.6439790606
C -3.1167403693 0.7222692865 -0.5564464136
H -3.6652721225 1.426528195 0.0563380898
C -3.7825574498 -0.3079933726 -1.2501288179
H -4.8635656361 -0.398323351 -1.1764982187
C -3.0598665441 -1.1804543514 -2.0255195184
H -3.5254485302 -1.9644215562 -2.6115397389
C -1.6459521501 -1.0335940928 -2.1484521473
N -0.9994263412 -0.0966556963 -1.3694160046
N 1.0554398216 -0.6066607197 -3.0431006257
C 0.1491771933 -1.4740732398 -3.6161132953
C 0.4385366523 -2.0339294922 -4.8957041781
H -0.2697898436 -2.7538884063 -5.288847453
C 1.533197406 -1.6086162157 -5.6070413496
H 1.7417050913 -2.0117717669 -6.59499957
C 2.3860711534 -0.6332780249 -5.0541142069
H 3.2550409632 -0.2814111053 -5.5956531171
C 2.1091579276 -0.1794356892 -3.7732515102
H 5.3359917397 -0.8826750572 1.2108991239
C 4.8812042503 -0.5409414174 0.2897595626
C 3.4875047272 -0.5183302919 0.1529249227
N 2.8770205097 -0.0870053371 -0.9734691835
C 3.6451621575 0.3664930649 -1.9938210969
C 5.0422275366 0.4046712796 -1.9124080149
H 5.6305267969 0.7539131554 -2.7511966421
C 5.6598610771 -0.0687223998 -0.7591128441
H 6.7434855914 -0.0675461413 -0.6790213138
N -1.0422734472 -1.7816898961 -3.0822147839
N 2.964315799 0.7844879216 -3.1462491683
N 2.6664783489 -0.899770074 1.2241751739
N -1.0025675354 1.784544601 0.064153823
Co 0.9238112259 -0.2384814336 -1.1380923064
C -1.6796792487 3.0614093813 0.2695473456
H -2.1281226004 3.3678831605 -0.6778810669
H -0.9389233345 3.8100521815 0.56433899
H -2.4717431195 3.0341610319 1.0339438517
C 3.6549565148 1.7208034991 -4.0279421681
H 2.9287993396 2.1239715315 -4.737198422
H 4.4845950305 1.2754254307 -4.5986534647
H 4.0508148284 2.5437705055 -3.4263304194
C 3.1704029677 -1.8953649599 2.1652856855
H 3.6341888567 -2.7014711606 1.5926659415
H 2.3210475817 -2.312755443 2.7099689238
H 3.8976676115 -1.4949259183 2.8879711256
C 0.9630670569 -2.2385287714 -0.5730795546
O 1.7655711605 -3.1013401177 -0.9152124636
O -0.0412371869 -2.6369284725 0.3151697916
H 0.0704453268 -3.6052539057 0.4399042454
Listing S52. Coordinates of 5
(II)
-CO2H, deprotonated.
231
H 2.7267416476 -0.3366588611 3.5660378003
C 1.9957103303 0.1174469993 2.9098489629
C 1.0362357349 0.992477937 3.4131587927
H 1.0012796553 1.2103853477 4.4764849138
C 0.1196459238 1.5779505022 2.5503661592
H -0.6566312221 2.230998862 2.9275884094
C 0.1874310534 1.2678943241 1.186554768
N 1.1389534907 0.4455370968 0.6858871059
C 2.0219556671 -0.1275217423 1.5356701905
C -1.4187605061 0.8964692792 -0.5844828972
C -2.8154304348 0.8963636739 -0.6850120555
H -3.4079990551 1.5862959445 -0.0980616816
C -3.4240266558 -0.0383322687 -1.5118612545
H -4.5059269685 -0.0647642671 -1.6025023356
C -2.6410077571 -0.9495958356 -2.2164062108
H -3.0985567277 -1.6764130415 -2.8749033536
C -1.252581358 -0.8799402744 -2.086037032
N -0.6498029911 0.0364182822 -1.2937956283
N 1.4400600742 -0.3339854536 -3.1042689716
C 0.5621102478 -1.2036747452 -3.6560954713
C 0.5938863154 -1.5294032081 -5.013490676
H -0.1346216788 -2.209196045 -5.4356874799
C 1.5581263312 -0.9316112667 -5.8211888131
H 1.599330167 -1.1608610832 -6.8819225632
C 2.4730657117 -0.0500432601 -5.261405562
H 3.2554944338 0.3931700367 -5.863918991
C 2.3965238657 0.2170009904 -3.8889553301
H 5.6808789731 -0.8343940088 1.015489162
C 5.2221290483 -0.4338153775 0.1209072099
C 3.834758929 -0.4409760959 -0.0332044391
N 3.2296158858 0.0773664834 -1.126430818
C 3.9948632424 0.6009601415 -2.1124575677
C 5.3902042274 0.664732449 -2.0115459164
H 5.9812730066 1.0809206134 -2.816940144
C 6.0012126727 0.1400599021 -0.8808288738
H 7.0821256405 0.171015915 -0.7806253741
N -0.406091828 -1.7642949721 -2.7925566808
N 3.3420515931 1.0461745304 -3.2703473355
N 2.9899868128 -0.9832843984 0.9625851642
N -0.7661731636 1.773587389 0.291715202
Co 1.2889484728 0.2164470679 -1.2432748492
C -1.4168817238 3.0452716055 0.617569908
H -1.8419039908 3.458093448 -0.2991171025
H -0.6545005184 3.7380073386 0.9789559219
H -2.2102682521 2.9505832492 1.3717697097
C 3.9923104839 2.0828465503 -4.0763387405
H 3.2379812007 2.5470360503 -4.7140657229
H 4.808550268 1.7003316965 -4.7045020779
H 4.3824221731 2.8473659749 -3.4017896137
C -0.970399543 -3.0617784211 -3.176890468
H -0.1513153341 -3.7270065015 -3.45820253
H -1.6826958095 -3.0074723776 -4.0121485042
H -1.4794634541 -3.4889753864 -2.3103418951
C 3.5611652489 -2.0191128796 1.8287093068
H 4.0754116199 -2.7504024676 1.2015204403
H 2.7451241179 -2.524517593 2.349609211
H 4.2705472802 -1.6350231716 2.575228064
C 1.3243880937 2.2454049773 -1.6157771132
Listing S53. Coordinates of 6
(II)
-CO2H.
O 0.4992845168 2.682526809 -2.6539723808
O 1.9848880687 3.0944659205 -1.0303428574
H 0.6158367462 3.6560576155 -2.7197990903
232
H 2.6252126463 -0.3484213823 3.5256743209
C 2.0215256302 0.2017011547 2.811310072
C 1.2194779253 1.2624246312 3.2157018968
H 1.1726910848 1.544823199 4.2630387769
C 0.4699652066 1.9540085335 2.2672728865
H -0.1908324034 2.7651780059 2.5546292398
C 0.5419350953 1.543196596 0.9382384862
N 1.3519394876 0.5397617821 0.5176795061
C 2.0803293642 -0.1163718443 1.4521120665
C -1.1082990998 1.3465408756 -0.8276207497
C -2.4762119512 1.6030932136 -0.8854338388
H -2.8991281659 2.443037395 -0.3442580987
C -3.2848395965 0.7251959056 -1.6030206956
H -4.3575696209 0.8852006663 -1.6531652346
C -2.7080269244 -0.3628255909 -2.2476296075
H -3.3110452838 -1.0571076313 -2.8236138667
C -1.3213525378 -0.522404065 -2.1866055628
N -0.5212959681 0.3160173817 -1.4857697584
N 1.4465433703 -0.7019729497 -3.2122157314
C 0.4016792848 -1.4126102719 -3.6998401236
C 0.4032166299 -1.9683389726 -4.9816566282
H -0.4571277582 -2.5281866255 -5.3334165659
C 1.4998556924 -1.7449444786 -5.8060352838
H 1.5169416802 -2.1464168226 -6.8146956521
C 2.5798126053 -1.0094373183 -5.3241748126
H 3.4643031707 -0.845833538 -5.9309182779
C 2.5258343785 -0.5331361889 -4.0162418036
H 5.4822920874 -1.8247277803 1.0214952713
C 5.1354166069 -1.4083818837 0.0814493223
C 3.8041523765 -1.0086523244 -0.0594206084
N 3.3194524622 -0.479819423 -1.2083245031
C 4.1769662338 -0.3385303968 -2.249735593
C 5.5291933602 -0.6629859694 -2.1687932881
H 6.1771610401 -0.5289708111 -3.0286556433
C 6.0082074645 -1.2134718585 -0.9826156802
H 7.0530546752 -1.4943985515 -0.8918186389
N -0.7160485195 -1.5750888476 -2.8775243309
H -1.3895426349 -2.2305449859 -3.2585157354
N 3.6279124531 0.1315404338 -3.4539235396
H 4.337500053 0.3607312628 -4.14248049
N 2.9254295262 -1.1408821871 1.0185736255
N -0.2653107389 2.147430679 -0.0395569712
H -0.7294591444 2.98347643 0.3009170108
Co 1.438131592 0.0858949284 -1.4019687764
H 3.3257832787 -1.668281395 1.7866295919
C 1.887292369 2.0298533493 -2.0387555997
O 2.1281915166 3.0838976707 -2.3791503838
Listing S54. Coordinates of 1
(II)
-CO.
233
H 2.5445345817 -0.3424374231 3.5337784534
C 1.9423457026 0.2208668442 2.8311500532
C 1.0490381154 1.1817742171 3.2312131709
H 0.8978076994 1.3929648945 4.285830115
C 0.3188466455 1.8935880175 2.2578413387
H -0.4177636336 2.6407638419 2.5345031339
C 0.5223410513 1.5664856619 0.9326813592
N 1.4159297731 0.6380730344 0.5023949712
C 2.1893874575 -0.0169356205 1.444562781
C -1.0960658229 1.3865747423 -0.8436368585
C -2.4710403733 1.6254357445 -0.9256899039
H -2.905986298 2.4758556281 -0.411313457
C -3.2611817882 0.7149773159 -1.6166025127
H -4.3358128948 0.8575613402 -1.6789476974
C -2.6653007351 -0.3899529899 -2.2173652385
H -3.2530212237 -1.1140864099 -2.7718661007
C -1.2772178481 -0.5258656012 -2.1385758952
N -0.4927314086 0.3460695832 -1.4686881139
N 1.4756020324 -0.674259047 -3.1961866444
C 0.4403152391 -1.4161673538 -3.6461877422
C 0.4144492775 -1.9858780996 -4.9214078483
H -0.4425571827 -2.5700479252 -5.2399483418
C 1.4817229802 -1.7429320181 -5.7808544513
H 1.4794699836 -2.1557038483 -6.7851823035
C 2.5550452378 -0.9797089327 -5.3380098139
H 3.4214858006 -0.8039445691 -5.9667704355
C 2.5312542551 -0.4937422009 -4.0273892577
H 5.497418942 -1.8537653679 0.9510629291
C 5.1657993314 -1.4343547476 0.0088736229
C 3.8525813859 -0.8731029674 -0.0129496545
N 3.3580680501 -0.3664568026 -1.2020669284
C 4.1839749357 -0.3264254138 -2.2800719344
C 5.4897658671 -0.7731286652 -2.2757713352
H 6.0940074525 -0.7187804555 -3.1753594401
C 5.9822844136 -1.3557577477 -1.0904763421
H 6.9970141116 -1.7415153174 -1.0556887562
N -0.6520098373 -1.5953606718 -2.7897760885
H -1.318653544 -2.2668556742 -3.1523534909
N 3.6222414008 0.1825469066 -3.4875925064
H 4.3390995452 0.373742051 -4.1793797386
N 3.2148179143 -0.8239664431 1.1597203588
N -0.2659866735 2.1977648857 -0.0740815929
H -0.7508757125 3.0111275989 0.2896668172
Co 1.4994171118 0.1888188804 -1.3927467857
C 1.9307689481 2.0701033645 -2.0117009461
O 2.3148797332 3.1245777607 -2.1981309482
Listing S55. Coordinates of 1
(II)
-CO, deprotonated.
234
H 2.6591338127 -0.3457988678 3.5039014168
C 2.0620120701 0.1966665961 2.7828074822
C 1.3162842813 1.3051229112 3.1778079817
H 1.3222441329 1.6233201551 4.2159699878
C 0.5543967186 1.9905124025 2.2394302552
H -0.0726645677 2.8293075712 2.5235287545
C 0.5711371788 1.5359620305 0.9209166738
N 1.3404333096 0.5022787678 0.5081492002
C 2.0665980204 -0.175180249 1.4366683679
C -1.1101907201 1.3316027181 -0.8250075497
C -2.4773035831 1.5953934942 -0.8746558209
H -2.8942019335 2.4333549225 -0.3258098328
C -3.2930149515 0.7278634075 -1.5970664453
H -4.3650266468 0.8942251282 -1.6414169623
C -2.7252335331 -0.3563202951 -2.2564694783
H -3.334668174 -1.0399022211 -2.8385010638
C -1.3393923124 -0.5251777449 -2.2009837728
N -0.5341098671 0.3008838794 -1.491967805
N 1.4318104777 -0.7166694061 -3.2170746417
C 0.3870227001 -1.4193737437 -3.7153176927
C 0.3997428905 -1.975115818 -4.9972265098
H -0.4597376938 -2.5296416882 -5.3594513695
C 1.5078429933 -1.7586556932 -5.8082341109
H 1.5346007083 -2.1615548707 -6.8161092182
C 2.585545189 -1.026196388 -5.3162484087
H 3.4760709959 -0.8653030531 -5.914809544
C 2.5192308814 -0.5472345588 -4.0096798397
H 5.4665932763 -1.7932073419 1.0419526907
C 5.1099359287 -1.3754712115 0.1097003719
C 3.7612489211 -1.0500716982 -0.0501034523
N 3.2915818346 -0.5066501043 -1.2044146951
C 4.1578741261 -0.3175525348 -2.226483656
C 5.5245228679 -0.5753457392 -2.1205063935
H 6.1838064022 -0.400706332 -2.9645079256
C 5.999280791 -1.1108143504 -0.929437331
H 7.0555639694 -1.3333919858 -0.8119263542
N -0.7411905323 -1.5732078472 -2.9054790017
H -1.4188482476 -2.2178933591 -3.2971374287
N 3.6122782036 0.1270616627 -3.4412996039
H 4.3228869908 0.366129491 -4.125223559
N 2.8317167258 -1.2663089571 0.9842882612
N -0.2579780199 2.1294842389 -0.0442801171
H -0.7122983075 2.9713078913 0.2945278936
Co 1.4173532075 0.0514952344 -1.4041467893
C 3.148058931 -2.3208677845 1.9646129707
C 1.875431478 2.0034300845 -2.0341819732
O 2.1214834295 3.0575091166 -2.3713157791
H 3.4765384807 -3.2087362149 1.4217793027
H 2.2359968773 -2.5703120882 2.5094407616
H 3.9260702879 -2.0315295569 2.6817617534
Listing S56. Coordinates of 2
(II)
-CO.
235
H 2.6305003732 -0.4008221661 3.4594440185
C 2.048632942 0.1726685956 2.7500439866
C 1.3355854331 1.2974256123 3.1645985341
H 1.3506508652 1.5962207565 4.2085490146
C 0.5933806127 2.0177161092 2.240962691
H -0.013519358 2.8668371614 2.5375571941
C 0.5887665171 1.5813506292 0.9111394256
N 1.3344749633 0.5381324885 0.4811931192
C 2.0373901601 -0.1725988782 1.397199493
C -1.1020403957 1.3591470098 -0.8022362095
C -2.4657998254 1.5557087917 -0.7175248715
H -2.8721675593 2.3433278423 -0.0914860003
C -3.3030980036 0.663872761 -1.4179164533
H -4.3822054727 0.7706386923 -1.3555428501
C -2.7423658597 -0.3369207497 -2.1709112218
H -3.3383918607 -1.0355313996 -2.7456984776
C -1.3246805271 -0.4444832965 -2.3041226291
N -0.5167316041 0.3917099147 -1.5544198655
N 1.4227234044 -0.6143311264 -3.2573145659
C 0.3370769452 -1.3084129028 -3.7611301933
C 0.4804266275 -2.0141469333 -4.9943045583
H -0.3806977696 -2.576574683 -5.3346449337
C 1.6272956097 -1.9012973003 -5.7391445128
H 1.7154226578 -2.4031461525 -6.6983785027
C 2.6991760013 -1.1289282565 -5.2475338905
H 3.6309859712 -1.0366071617 -5.7957590669
C 2.5512280739 -0.5373765625 -4.009118251
H 5.4050306141 -1.8155342488 1.0320722934
C 5.0730924419 -1.3752515705 0.1011275547
C 3.7304815249 -1.0419181658 -0.0871779534
N 3.2871772473 -0.4703473373 -1.233842162
C 4.1728494108 -0.2682479996 -2.2358967459
C 5.5415750004 -0.5273461008 -2.0995019204
H 6.216797439 -0.3386495497 -2.9276270779
C 5.987501203 -1.0877950752 -0.9121934966
H 7.0401318826 -1.3173163112 -0.77565595
N -0.8799779686 -1.3218763464 -3.2090710919
N 3.6420423259 0.1834032166 -3.4408001005
H 4.3581779878 0.3843668523 -4.1303273165
N 2.7747621813 -1.2758037668 0.9222358723
N -0.2247378044 2.1870474182 -0.042497747
H -0.702006541 3.0063035281 0.3176158723
Co 1.4118335287 0.1486248591 -1.4678472049
C 3.0548383814 -2.3577220997 1.8745559323
C 1.8436266192 2.0364332879 -2.0908227234
O 1.9275741153 3.0522767233 -2.596307852
H 3.3734466267 -3.2379012163 1.3128180607
H 2.1301704678 -2.602186889 2.4009245695
H 3.8289043941 -2.1075380041 2.6126187642
Listing S57. Coordinates of 2
(II)
-CO, deprotonated.
236
H 2.670253747 -0.325271233 3.5291932737
C 2.0683243266 0.2034887047 2.8019542351
C 1.3070577183 1.3053672092 3.1862343205
H 1.3049034017 1.6300399532 4.2224025447
C 0.5430593484 1.9781541897 2.2403604237
H -0.0916529749 2.8137657896 2.5166558927
C 0.5710934145 1.5166158179 0.9242825808
N 1.3483224537 0.4839527853 0.5246640273
C 2.0807400789 -0.1784948869 1.4586469866
C -1.0889146668 1.319673706 -0.8525026133
C -2.4461013579 1.6238582974 -0.959628591
H -2.8584633723 2.4864232172 -0.4463844226
C -3.253416639 0.7643346255 -1.6947490156
H -4.3162068152 0.9634196586 -1.7943404318
C -2.6954157722 -0.3622764738 -2.2953846259
H -3.3135721163 -1.0358867759 -2.8741016552
C -1.3211718158 -0.5830604159 -2.1805957946
N -0.5222674518 0.261251288 -1.4759883328
N 1.4264767065 -0.7462988297 -3.1857476144
C 0.3763019627 -1.4607292553 -3.6698716058
C 0.3641652568 -1.9441853031 -4.9800748584
H -0.4875408792 -2.4969498772 -5.3539661713
C 1.4431055512 -1.6640084241 -5.8159755243
H 1.4387818426 -2.0120965835 -6.8445111749
C 2.5276671167 -0.9480721056 -5.3239112459
H 3.3999718374 -0.7501288089 -5.938203382
C 2.4906486481 -0.5315114661 -3.9931058038
H 5.4980121803 -1.7865553533 1.0485384232
C 5.1293333989 -1.3780494471 0.1168722643
C 3.7783951283 -1.0559330946 -0.0308570841
N 3.2967587749 -0.5237521734 -1.185166323
C 4.1513640958 -0.3341070015 -2.2167160225
C 5.5189863204 -0.5927708601 -2.1242279559
H 6.1699379582 -0.4213867682 -2.9753003326
C 6.0060849129 -1.1220399969 -0.9352824336
H 7.0635547363 -1.3442373001 -0.8282061076
N -0.7048245362 -1.6885877647 -2.7971817024
C -1.5482154382 -2.8680540156 -3.0637311346
N 3.5961073289 0.1204381199 -3.4235103198
H 4.3003635987 0.3707117774 -4.1098359286
N 2.8593007948 -1.2644440823 1.0151048734
N -0.2467436746 2.1079940953 -0.0518995501
H -0.6979088796 2.9558952333 0.2754627915
Co 1.4199106413 0.0089096639 -1.3764330238
C 3.1920416861 -2.304099916 2.0059402205
C 1.8735774512 1.9774747745 -2.0207018161
O 2.1155026586 3.0308203588 -2.3633804364
H 3.5260809465 -3.1952705909 1.4718859335
H 2.2859533496 -2.556379461 2.5594515002
H 3.9715314469 -1.9980440702 2.7145565398
H -0.8964555441 -3.7223256268 -3.2547458172
H -2.2255872672 -2.7365275913 -3.9165277561
H -2.1372616182 -3.0803637125 -2.1698902238
Listing S58. Coordinates of 3
(II)
-CO.
237
H 2.9068788053 -0.2211540924 3.4700172567
C 2.2309856941 0.2639484683 2.7778123323
C 1.4975059212 1.4036150032 3.1663476169
H 1.6060843816 1.7958169743 4.1735668788
C 0.6427781595 2.0014678642 2.273582783
H 0.02820412 2.8548096568 2.5347177962
C 0.4702676626 1.4514097164 0.9711146302
N 1.2740371576 0.4014968337 0.5740551265
C 2.0995479318 -0.1877556146 1.4772439652
C -1.1357016066 1.2607248471 -0.7477994784
C -2.4741621987 1.631596516 -1.0634324395
H -2.8721958422 2.5109550937 -0.5710913034
C -3.2301403694 0.842165034 -1.8943685322
H -4.2634630189 1.0988990211 -2.109858879
C -2.6657807701 -0.3182566134 -2.4625458312
H -3.2486982835 -0.9532507218 -3.1170187897
C -1.3368281584 -0.5966315879 -2.1994544674
N -0.5673965889 0.1824760623 -1.3961515925
N 1.3892428856 -0.7358656121 -3.1573667356
C 0.3737449184 -1.4976601849 -3.6463831601
C 0.4100517351 -2.0085834878 -4.9511343559
H -0.4128577993 -2.6009325912 -5.3284911639
C 1.4860206903 -1.6913774395 -5.7730204701
H 1.5141104244 -2.0541697596 -6.7962588722
C 2.5284643936 -0.9149906841 -5.2772789657
H 3.4013163368 -0.6853948747 -5.879541437
C 2.4499077087 -0.4847957725 -3.9524893555
H 5.489556264 -1.9007719996 0.9851529845
C 5.1107913251 -1.4505965063 0.0771645588
C 3.7587405202 -1.0949501374 -0.0250705652
N 3.2642809378 -0.5127615321 -1.1508463314
C 4.1025203426 -0.2889668085 -2.1842590778
C 5.4685102647 -0.5673479039 -2.1322024004
H 6.1038030413 -0.3669383814 -2.9886502791
C 5.9691164966 -1.160300596 -0.9776363369
H 7.0252061138 -1.4017972219 -0.9016092841
N -0.7007252376 -1.733973671 -2.7889874097
C -1.5523470044 -2.8935460322 -3.0741069596
N 3.5265031048 0.2087542367 -3.3682777752
H 4.2258481162 0.4771048937 -4.0518180953
N 2.8568400012 -1.3102567161 1.0166440423
N -0.517973801 1.960575844 0.2177634965
Co 1.3531475169 -0.0262790823 -1.3102008489
C 3.2051487495 -2.3270273032 2.0145240536
C 1.715242142 1.9646946277 -1.8705935464
O 1.9161050186 3.0399151717 -2.1769522037
H 3.5116370195 -3.2384346611 1.4957621864
H 2.313007588 -2.5463773571 2.6034792564
H 4.0094468401 -2.0191400779 2.6968190187
H -0.9156032536 -3.7665340744 -3.2359924119
H -2.2015034389 -2.7600640108 -3.9503846973
H -2.179382958 -3.0787727553 -2.2004139304
Listing S59. Coordinates of 3
(II)
-CO, deprotonated.
238
H 2.5716784129 -0.4017656552 3.4957675504
C 2.0011455252 0.1629276724 2.770335327
C 1.2562444606 1.2686038734 3.1653163531
H 1.2293467635 1.561173304 4.2107584058
C 0.5365862996 1.9921941161 2.2195786391
H -0.0779113454 2.8313221301 2.5180407297
C 0.5817153793 1.5769652659 0.8881985097
N 1.3458438459 0.528699662 0.485396108
C 2.0390767324 -0.1765597673 1.4151646516
C -1.0777890419 1.3678381606 -0.8306644939
C -2.4537121148 1.5885961116 -0.841660152
H -2.8835610784 2.4234915233 -0.3037853511
C -3.2734475748 0.6829163313 -1.5150332596
H -4.3503773047 0.8215816811 -1.5186052872
C -2.7060638945 -0.3958827728 -2.1782732263
H -3.3177809416 -1.1029888444 -2.7291475075
C -1.3142501882 -0.5288850064 -2.1661726614
N -0.5093693692 0.3241680764 -1.4941682159
N 1.4478304713 -0.7056555888 -3.2226108738
C 0.3992915549 -1.4106353633 -3.7082913095
C 0.4008308509 -1.9677247237 -4.9896115689
H -0.4617565695 -2.5219531953 -5.3447614754
C 1.5043807152 -1.7552723011 -5.8083889447
H 1.5228651589 -2.1599440464 -6.8157425639
C 2.5893532729 -1.0275760559 -5.3250562486
H 3.477249118 -0.8739323102 -5.9294130068
C 2.5330005716 -0.5444394219 -4.0193920198
H 5.4524208516 -1.7803086583 1.0496098744
C 5.1039288081 -1.3634368305 0.1138013292
C 3.7570643767 -1.0380291203 -0.0589960419
N 3.300905622 -0.4929340596 -1.2170239641
C 4.1724021257 -0.3129313995 -2.2355246497
C 5.5376820403 -0.5741122809 -2.1181635276
H 6.2040182974 -0.4071228196 -2.9581743409
C 6.0016940823 -1.103113025 -0.919775149
H 7.0567121633 -1.3265525958 -0.7928463136
N -0.7166809367 -1.5700012446 -2.8825273828
H -1.3937236167 -2.2231787439 -3.2608575406
N 3.632995508 0.1234160142 -3.4562697855
H 4.3459854433 0.3515683794 -4.1413742047
N 2.8126216114 -1.2619438395 0.9608248848
N -0.198969972 2.2045333073 -0.106974398
C -0.6359873851 3.5892807582 0.1425701851
Co 1.4352281567 0.0773280617 -1.4199540722
C 3.1142168646 -2.330138037 1.9309267175
C 1.8917447278 2.0137943668 -2.0511154602
O 2.134166915 3.0703951064 -2.3868098228
H -1.004354387 4.0095500139 -0.7949030771
H 0.2288892459 4.1723738735 0.4641653075
H -1.422695145 3.6676418287 0.902862071
H 3.4538090776 -3.2094066834 1.3809548216
H 2.193659637 -2.5900587142 2.4563651621
H 3.8793761778 -2.0498665135 2.6653012692
Listing S60. Coordinates of 4
(II)
-CO.
239
H 2.5864405033 -0.3786950557 3.4446083685
C 2.0248630119 0.2054485773 2.7274892597
C 1.3436658165 1.3530811136 3.124565007
H 1.3593165429 1.6609978613 4.1660107718
C 0.6285968441 2.0914633602 2.1907462578
H 0.053476204 2.9573077787 2.4914426362
C 0.6080267426 1.6481739172 0.8624521239
N 1.3322093165 0.5736287051 0.4543197533
C 2.0098022036 -0.1481239989 1.3760085044
C -1.0777218857 1.3559157726 -0.8000906078
C -2.4442703105 1.4673745842 -0.6407251239
H -2.8709183296 2.240610983 -0.0148236275
C -3.267415867 0.5130235969 -1.2765907479
H -4.3449155156 0.5574226566 -1.1460266896
C -2.6989996564 -0.4593375403 -2.0578502938
H -3.2868377164 -1.1955040695 -2.5931851947
C -1.2869219256 -0.4848127731 -2.2728786886
N -0.490285396 0.3964651941 -1.5667146856
N 1.451864036 -0.598201304 -3.2726748663
C 0.3611764712 -1.2745204136 -3.7882127086
C 0.486374835 -1.9246003202 -5.0528516441
H -0.3812755403 -2.4673041278 -5.4082205114
C 1.6291870551 -1.7913900528 -5.8014580297
H 1.7050110144 -2.2533528559 -6.7815733609
C 2.7146285893 -1.0563583296 -5.2845697913
H 3.6462730901 -0.9587449531 -5.8322449978
C 2.5799336334 -0.5101177072 -4.0234483234
H 5.3457435242 -1.8842418595 1.0528571961
C 5.0349266649 -1.4330380777 0.1198546768
C 3.7038156742 -1.0629139087 -0.0818480441
N 3.2903661947 -0.4773563257 -1.2321499578
C 4.1894408179 -0.2968363816 -2.2253461329
C 5.5490590425 -0.594103871 -2.0754968087
H 6.2382799067 -0.4232963788 -2.8959488416
C 5.9665433929 -1.1686806798 -0.8842352906
H 7.011047068 -1.4273316094 -0.7376000628
N -0.8430409093 -1.329349617 -3.2087648145
N 3.6828799179 0.1730095893 -3.4342858799
H 4.4114763825 0.3630170756 -4.1136879244
N 2.7274432361 -1.2719676522 0.9126330531
N -0.186142808 2.2491504323 -0.1168653728
C -0.6664067723 3.6124196063 0.1280130904
Co 1.4299478618 0.1655618366 -1.4848946305
C 2.968461237 -2.3567593817 1.8720694237
C 1.8701737184 2.0410196889 -2.106982873
O 1.9412171198 3.0639577934 -2.6027465357
H -1.0995045559 3.9931760346 -0.7984560889
H 0.184708263 4.2421317508 0.3986910199
H -1.4230074345 3.6766585682 0.9218305987
H 3.2697710385 -3.2476533669 1.3175705892
H 2.0320504887 -2.5748739889 2.3891572171
H 3.7407371636 -2.124359876 2.6178896035
Listing S61. Coordinates of 4
(II)
-CO, deprotonated.
240
H 2.5686918436 -0.3955003506 3.5215910875
C 1.9951507287 0.1578642637 2.7898499493
C 1.2303891123 1.2531544822 3.1758488126
H 1.1895560216 1.5463370403 4.2206648774
C 0.5117261068 1.9679391031 2.2224127931
H -0.1139061824 2.8013649267 2.5138233065
C 0.576219961 1.5533700854 0.891639743
N 1.3506416977 0.5086354931 0.5006245457
C 2.0478056178 -0.1851309319 1.4357159408
C -1.0597130243 1.3619020869 -0.8613228502
C -2.4282701416 1.6254781321 -0.9319432903
H -2.8543650342 2.4846980815 -0.4307562049
C -3.2420504068 0.7296332061 -1.6186473049
H -4.3122818933 0.903304836 -1.6795924512
C -2.6839067483 -0.392784487 -2.2206223504
H -3.3061260751 -1.0876104857 -2.7689882589
C -1.3008437451 -0.5809730609 -2.146449645
N -0.5013414531 0.2893932189 -1.4795066144
N 1.4391328794 -0.7310292463 -3.1928877558
C 0.3845581177 -1.4469356918 -3.6629856649
C 0.3595511723 -1.9324104454 -4.9722601743
H -0.4963074163 -2.4844617555 -5.3378504613
C 1.4334621379 -1.6576102535 -5.8168995193
H 1.4196318997 -2.0078009786 -6.844644827
C 2.5264866391 -0.9472825688 -5.334990262
H 3.3957761236 -0.7575674252 -5.9561238732
C 2.5009329098 -0.5259837837 -4.0052105212
H 5.4829391602 -1.7686578692 1.0539830994
C 5.12201687 -1.3615648316 0.1185806541
C 3.7720122827 -1.0420523082 -0.0423042011
N 3.3032668427 -0.508560451 -1.2004057613
C 4.1631321189 -0.3265270289 -2.2283692246
C 5.530047898 -0.5856064327 -2.1239292962
H 6.188073375 -0.4201761942 -2.9707452095
C 6.0070947389 -1.1077412139 -0.9275683284
H 7.0638377632 -1.3284910193 -0.8107158376
N -0.6826839579 -1.6796208429 -2.7743873494
C -1.5138193016 -2.8717630739 -3.0222736587
N 3.6141003163 0.1180993105 -3.4416350282
H 4.3205056849 0.3577848684 -4.1294184422
N 2.8391516493 -1.2610622027 0.9895515435
N -0.1873869951 2.1849202238 -0.115116771
C -0.6065730991 3.5771562649 0.1242183996
Co 1.4352668498 0.0392341855 -1.3943798321
C 3.1586156524 -2.3162838812 1.9682887411
C 1.8886614663 1.9869604208 -2.0363551344
O 2.1259264436 3.0439970008 -2.3750330491
H 3.5075868078 -3.1961677076 1.4253007111
H 2.2439870128 -2.5832096802 2.5004683478
H 3.9232526355 -2.0184288707 2.6962946403
H -0.9420317393 4.0052794405 -0.8220604106
H 0.259289243 4.1446523444 0.4697768297
H -1.4118708476 3.6678705405 0.8633426149
H -0.8535819822 -3.7162073025 -3.2270182992
H -2.2108726738 -2.7508898024 -3.8606940212
H -2.0806550633 -3.0928573781 -2.116264753
Listing S62. Coordinates of 5
(II)
-CO.
241
H 2.4639876532 -0.4592769256 3.5527002179
C 1.9252945066 0.106243269 2.8040731766
C 1.1710421974 1.2147914657 3.1633724774
H 1.0979152949 1.5074353765 4.2067879888
C 0.5049871862 1.9496287226 2.1851741067
H -0.1140004404 2.7958769368 2.4528825761
C 0.6101570506 1.53099585 0.8582831821
N 1.3732592929 0.474446747 0.490758206
C 2.0300341596 -0.2325241699 1.4467732356
C -1.0200279327 1.342250015 -0.8903083368
C -2.3876546904 1.6176466356 -0.9236758888
H -2.7901867637 2.4924279548 -0.4299807229
C -3.2284653703 0.70691571 -1.5592661837
H -4.2992588189 0.88615702 -1.5903975109
C -2.6973136006 -0.4317000909 -2.1495233352
H -3.338247923 -1.1353428725 -2.663880733
C -1.3080659885 -0.6241471767 -2.1244122095
N -0.4854599476 0.2557806599 -1.496812783
N 1.4575746512 -0.8393137601 -3.1708963361
C 0.3562199341 -1.4544563584 -3.67185373
C 0.241050162 -1.8118126782 -5.0032444005
H -0.6550257676 -2.2909275492 -5.3760667228
C 1.3048134687 -1.495660603 -5.8729199416
H 1.2264050072 -1.7392768077 -6.928710003
C 2.4373632776 -0.8960397682 -5.3786480546
H 3.2971335721 -0.6713436477 -5.9986706876
C 2.5507885002 -0.6240197257 -3.9854385146
H 5.4907732067 -1.5422881106 1.1913928415
C 5.132382931 -1.2159473963 0.2236343324
C 3.7808270524 -1.0421793079 -0.0136824848
N 3.2950914191 -0.6196524255 -1.2085206957
C 4.1575157441 -0.4283412792 -2.2687860774
C 5.5607632572 -0.5109844383 -2.0399346717
H 6.2126322055 -0.3080750175 -2.8813930237
C 6.0359629297 -0.914143425 -0.8159442445
H 7.1041955647 -1.013866113 -0.6452915388
N -0.7055703435 -1.7159118602 -2.7505103512
C -1.5426770986 -2.8884697628 -3.0251505026
N 3.7498780204 -0.2214107609 -3.5320713973
N 2.819349359 -1.2980063982 1.0135900386
N -0.1207256388 2.16643977 -0.1734385652
C -0.5054368104 3.5672880432 0.0343769874
Co 1.4612610812 -0.0504429893 -1.4086133677
C 3.163280801 -2.3325285294 1.9947267644
C 1.9849495901 1.8402090333 -2.1107571807
O 2.2542464096 2.8818717086 -2.4787578473
H 3.5592832578 -3.1947780499 1.4557716376
H 2.2544520672 -2.6382535733 2.5184962095
H 3.9082870023 -2.0088802239 2.7346052204
H -0.8283799873 3.9832048659 -0.9221108361
H 0.3733300312 4.121086787 0.3707225844
H -1.3109936849 3.6996127023 0.7691067253
H -0.8870938683 -3.7231073511 -3.2789084121
H -2.2552681784 -2.7390075255 -3.8480187715
H -2.0972349911 -3.1459026016 -2.1196224457
Listing S63. Coordinates of 5
(II)
-CO, deprotonated.
242
H 2.5817151623 -0.3981234165 3.5006608926
C 2.0046447664 0.1613663779 2.7762618121
C 1.2447851315 1.2564101988 3.1738762338
H 1.2133555757 1.5442596807 4.2204998241
C 0.5161803736 1.9759103376 2.231412206
H -0.1088851275 2.8057670492 2.5340513525
C 0.5702951149 1.5696948672 0.8972605844
N 1.3452426747 0.5299498189 0.495785457
C 2.0440649534 -0.1749938852 1.4201840795
C -1.066550322 1.3799994114 -0.8578812911
C -2.4362810729 1.6359665603 -0.9396933533
H -2.8724967459 2.4906397976 -0.4394244114
C -3.2383591101 0.7372699274 -1.6366161758
H -4.3087194086 0.9062024714 -1.70780357
C -2.6700974018 -0.3837190569 -2.2327095057
H -3.284467855 -1.082987475 -2.784457605
C -1.2872557287 -0.5658799698 -2.1442368696
N -0.4991944323 0.3129907554 -1.4763607867
N 1.4510671038 -0.6975447412 -3.1881698521
C 0.4160552688 -1.4510368545 -3.6362580705
C 0.4095665451 -1.9866472269 -4.927255174
H -0.4310582233 -2.5705079756 -5.2782419297
C 1.4832047479 -1.7188320432 -5.769994045
H 1.4902128303 -2.1120949493 -6.7822105938
C 2.5532346844 -0.9561001117 -5.3116932167
H 3.4114501351 -0.7736319689 -5.9450686172
C 2.5160121731 -0.4779602458 -4.0009524191
H 5.4405093174 -1.8617932364 0.9971447098
C 5.0888225466 -1.4209057683 0.0737112615
C 3.7489991651 -1.0518109795 -0.0748999826
N 3.2959013944 -0.4773350126 -1.2169441411
C 4.1551492685 -0.2789194254 -2.2491374072
C 5.5113809158 -0.5930115524 -2.1491792907
H 6.1819389163 -0.4292061232 -2.9825446565
C 5.9731819379 -1.1707293219 -0.9703514766
H 7.0217104449 -1.4344520251 -0.8687509036
N -0.6572918837 -1.6704434877 -2.7508133808
C -1.4791207563 -2.8733095422 -2.9755566997
N 3.6010939815 0.2339056836 -3.4428239752
C 4.5118528716 0.9224402587 -4.373967406
N 2.8166323289 -1.2595341396 0.9605887622
N -0.2042081416 2.2028840923 -0.1000978263
C -0.6362763042 3.5883423734 0.1533386723
Co 1.4358551321 0.0790080475 -1.3993692797
C 3.116322302 -2.3296229326 1.9290647853
C 1.8817812906 2.0121769269 -2.0321832508
O 2.1240815569 3.0680119643 -2.3748349061
H 3.4396915579 -3.214339569 1.378025469
H 2.1989806945 -2.5779112781 2.465535355
H 3.8926061854 -2.0559917475 2.65426834
H -0.976145674 4.0232600889 -0.7882261299
H 0.2240606151 4.1608704619 0.5042812945
H -1.4421169302 3.6632707393 0.8937258931
H -0.8129096178 -3.7195902594 -3.1516396693
H -2.1687978228 -2.7783437577 -3.8233852239
H -2.0537346071 -3.0740162016 -2.0697505213
H 3.9126192282 1.4833855191 -5.0932574147
H 5.1757572744 0.2388058226 -4.9171475647
H 5.1177309987 1.6309470482 -3.8063183911
Listing S64. Coordinates of 6
(II)
-CO.
243
H 2.1851711818 -0.5571487609 3.7325851033
C 1.5371712452 -0.0212590044 3.0438088873
C 0.4018651552 0.6363571665 3.4918974006
H 0.1370303279 0.6178511194 4.5455374975
C -0.3764009463 1.3404019589 2.5701038341
H -1.2578465342 1.8996896144 2.8604680387
C 0.0008699854 1.3312711748 1.2313642333
N 1.0950479081 0.6674045094 0.7666008833
C 1.8621186346 0.0409566535 1.6759986325
C -1.5529773355 1.0705948193 -0.4905356273
C -2.914308844 0.922544273 -0.2469425828
H -3.3838683977 1.5577700529 0.4947143377
C -3.6269533164 -0.0329525522 -0.9751254401
H -4.6910261683 -0.1792339425 -0.8109286382
C -2.9570835477 -0.7791304872 -1.9325014084
H -3.4796029702 -1.5138853401 -2.5396410528
C -1.5834753144 -0.5491231451 -2.1340113088
N -0.871237883 0.3295374118 -1.4070769066
N 1.3167034738 -0.5916497543 -3.2360914994
C 0.1971938061 -1.0012189549 -3.8770428109
C 0.1241606503 -1.2227780408 -5.2565168282
H -0.8157456203 -1.5164745735 -5.7138489224
C 1.2691973199 -1.0215535869 -6.0245471512
H 1.2442134038 -1.1623236934 -7.1012839122
C 2.4393162976 -0.6466264256 -5.3909701557
H 3.3607108645 -0.5057847193 -5.9480920292
C 2.4299670568 -0.4715859821 -3.9917224573
H 5.6166039721 -0.3652509284 1.3937246648
C 5.2270423822 -0.3086637119 0.3818929282
C 3.8473567552 -0.3551647471 0.1548022558
N 3.2795043041 -0.2461230751 -1.0688036417
C 4.1260737243 -0.1660293423 -2.1180394663
C 5.5270193733 -0.0835392942 -1.9783520784
H 6.1545305558 0.0114687322 -2.8594973811
C 6.0763602442 -0.1510044196 -0.7115393543
H 7.1516324445 -0.0880326103 -0.5714072514
N -0.9514065808 -1.294108426 -3.1301681842
H -1.6144929408 -1.8343772518 -3.6699553418
N 3.6565328685 -0.217239357 -3.4139082234
H 4.3693590326 0.0034791097 -4.0948887242
N 3.0328262858 -0.599145909 1.2682600062
N -0.8012411577 2.0052393496 0.2713777191
H -0.1672463408 2.5315843886 -0.3809001057
Co 1.2556860123 0.3472828104 -1.3324821686
H 3.573823076 -0.9279026861 2.0570443283
C 1.6504375798 2.2397011083 -1.9878610484
O 2.5588188322 2.2793912283 -2.8278189904
O 0.9399791439 3.1365952411 -1.4736400589
Listing S65. Coordinates of 1
(I)
-CO2 forming one intramolecular hydrogen bond. (Corresponds
to the structure labeled “1 H-bond” in Figure S49.)
244
H 2.997971616 0.9369953733 3.4137810464
C 2.1222517727 1.1081690786 2.7949361938
C 1.2353734267 2.1559805476 3.0645458967
H 1.403469991 2.8105086421 3.915412704
C 0.1269880035 2.3317078255 2.2528754761
H -0.6208096872 3.0897742005 2.4615835859
C -0.0555453015 1.455856072 1.1672550035
N 0.8450355328 0.5097897868 0.8381044045
C 1.8788512894 0.3146194552 1.6748220464
C -1.7322742691 0.5030619726 -0.4015793364
C -3.057637043 0.1289875517 -0.203664852
H -3.6058403481 0.5660319699 0.6231752478
C -3.6423331262 -0.7977519786 -1.0713849683
H -4.6725148165 -1.1154997157 -0.9405139035
C -2.8767409894 -1.2837486359 -2.1203591705
H -3.2942174747 -1.9738014847 -2.8492530304
C -1.547225633 -0.8493111658 -2.2542458457
N -0.9357601069 -0.0239705794 -1.3758626042
N 1.3395182892 -0.4165863082 -3.251532404
C 0.2625325332 -0.7149991912 -4.0095979169
C 0.224095116 -0.5506024238 -5.3982757014
H -0.6861534681 -0.7611521719 -5.9511802024
C 1.3666996145 -0.0699360764 -6.0383759285
H 1.3654754705 0.0980335187 -7.1116387392
C 2.5066975834 0.1779515924 -5.2923006365
H 3.4254454618 0.52073765 -5.7587593173
C 2.4609251688 -0.0519711806 -3.9026835913
H 5.21617616 -1.588367293 1.4842092808
C 4.905046803 -1.2728765089 0.4926320958
C 3.5969784417 -0.8144141662 0.2785091018
N 3.1252297337 -0.4156645991 -0.9234566708
C 4.0176437029 -0.3992863989 -1.9418045769
C 5.357195299 -0.8054709345 -1.805810202
H 6.0171422168 -0.7888867134 -2.6677740685
C 5.7966812206 -1.2627055952 -0.5730424286
H 6.8212317236 -1.5989308775 -0.4410955891
N -0.8497888058 -1.2885940275 -3.3823372617
H -1.4626885094 -1.7397793823 -4.0485040366
N 3.6461901065 0.0366422533 -3.2048726819
H 4.4330965844 0.2977367166 -3.7820729093
H 3.2420804531 -1.0552499403 2.226017155
N 2.7458105824 -0.7686532352 1.390874105
N -1.2386237058 1.520524041 0.4521098776
H -1.481334466 2.4575575821 0.1438394537
Co 1.0813320034 0.1769692465 -1.2645265761
C 1.2895160932 2.1921766926 -1.6746387477
O 2.4701805226 2.4387287866 -1.9621859631
O 0.2475652341 2.8607400286 -1.5795628141
Listing S66. Coordinates of the transition state for forming one intramolecular hydrogen bond in
complex 1
(I)
-CO2. (Corresponds to the structure labeled “TS 1” in Figure S49.)
245
H 2.4700745708 0.2109263942 3.796335426
C 1.7120378995 0.5762504548 3.1083580358
C 0.5879362662 1.237602551 3.5713524866
H 0.4459925453 1.3985504189 4.6364750717
C -0.3545786563 1.6935385142 2.645736177
H -1.2553454713 2.2180550924 2.9409236302
C -0.1227060489 1.4709935477 1.2938622603
N 0.987998846 0.845428607 0.8146533609
C 1.8772587211 0.3952796438 1.71917128
C -1.6560440682 0.8590624825 -0.4083634619
C -2.9299234328 0.4067416646 -0.0806578578
H -3.4564469135 0.8765265898 0.7415975029
C -3.4967129853 -0.6159035519 -0.8458073255
H -4.4897319682 -0.9949863666 -0.6204319182
C -2.7833016986 -1.1218215325 -1.9195815218
H -3.2022530541 -1.8975408605 -2.5554981806
C -1.5029191534 -0.5996708386 -2.194490414
N -0.9179050832 0.3405447612 -1.4290925967
N 1.3265069046 -0.1529242772 -3.3077912255
C 0.3482545893 -0.818192524 -3.9494712487
C 0.4885830638 -1.2978237282 -5.2685424449
H -0.3396698254 -1.8118466297 -5.7492851879
C 1.6814597311 -1.0860022449 -5.9375730556
H 1.8075669636 -1.4361987893 -6.9583631249
C 2.7141095248 -0.4144580137 -5.2776420232
H 3.6719773343 -0.21620937 -5.7432631513
C 2.5003408323 0.0217459746 -3.975753485
H 5.1711407188 -1.714264899 1.0737141275
C 4.8518340829 -1.2470517219 0.1456327808
C 3.6768094969 -0.468642004 0.1157739698
N 3.2131817997 0.1113189914 -1.0070361892
C 3.9833202343 0.0045884634 -2.1256655335
C 5.1608367904 -0.7341966493 -2.1741553777
H 5.7220455388 -0.7639273727 -3.1005506412
C 5.5935354871 -1.3848534904 -1.0157610752
H 6.5084350149 -1.9709605447 -1.0151934895
N -0.8556918561 -1.1070156832 -3.3158186772
H -1.4433116244 -1.7247561417 -3.8584647078
N 3.5503246489 0.6915669491 -3.2881166075
N 3.0022420298 -0.3198938817 1.3227267561
N -1.0837384837 1.9160928042 0.3438372668
Co 1.1853617543 0.6955092095 -1.3279463003
H 3.5091915905 -0.7131901066 2.1035431771
H -0.6023310894 2.5783219741 -0.3132436488
H 3.1976103942 1.6407003776 -3.0102161377
C 1.3431738633 2.6655219275 -1.792830701
O 2.335653343 2.9682284945 -2.4904478813
O 0.4326768324 3.3916353342 -1.337888118
Listing S67. Coordinates of 1
(I)
-CO2 forming two intramolecular hydrogen bonds. (Corresponds
to the structure labeled “2 H-bonds” in Figure S49.)
246
H 2.3628506495 0.3319508719 3.7683115133
C 1.6462714032 0.6841159033 3.0308141678
C 0.549977209 1.4432426412 3.4074086914
H 0.3904420655 1.694343309 4.4523551041
C -0.3411049672 1.8788700413 2.4220168486
H -1.2189592348 2.4713064216 2.6508564063
C -0.0889427837 1.5362072469 1.1001046162
N 0.9960201432 0.8141017603 0.7067434879
C 1.8366515742 0.3899583434 1.6660118848
C -1.5948183844 0.7853340705 -0.5402563165
C -2.8537778895 0.3487277775 -0.1376372046
H -3.3795055774 0.8960261806 0.6359602189
C -3.4048949947 -0.7695742887 -0.768675809
H -4.3835473625 -1.1428798853 -0.4791511776
C -2.7034794603 -1.3794099003 -1.7990724429
H -3.1163368368 -2.2284472811 -2.3374934989
C -1.4467928904 -0.8588429993 -2.1583339415
N -0.8671827688 0.1626988271 -1.5032061963
N 1.384793173 -0.4942424807 -3.2939130645
C 0.2892268216 -0.8954109512 -3.9732856942
C 0.1889414754 -0.8397682276 -5.3652746741
H -0.7305350524 -1.1349522622 -5.8619367446
C 1.2815314911 -0.3592639707 -6.0892621422
H 1.2308590938 -0.2848054324 -7.1720442297
C 2.4385853656 -0.005808496 -5.4133737431
H 3.333836562 0.3140389537 -5.9354862861
C 2.4619074574 -0.1230940568 -4.0126881392
H 5.3134264281 -1.3895016235 1.3581529685
C 4.9774820089 -1.1113972864 0.362545969
C 3.6930941781 -0.5615022194 0.1841615991
N 3.2054305417 -0.1926720679 -1.0195556853
C 4.0443769568 -0.3285244199 -2.0830792499
C 5.3255110266 -0.8658694199 -1.9866775132
H 5.9200803561 -0.9634183338 -2.8874697071
C 5.8023219107 -1.2676061574 -0.7374813537
H 6.797481374 -1.6888127351 -0.6282080587
N -0.7859708526 -1.4314742806 -3.2454355139
H -1.3947175984 -2.0056157451 -3.8136441201
N 3.671631064 0.1297169807 -3.3702173298
N 2.9274229607 -0.4144830292 1.3403840646
N -1.0074879164 1.9193197075 0.0802259315
Co 1.2751130424 0.4289611721 -1.3479290906
H 3.4231793604 -0.7306199109 2.1627132881
H -0.4762994848 2.4622005581 -0.6412825926
H 4.0003546861 1.0797336246 -3.537467305
C 1.6396817472 2.3578879954 -1.9525292037
O 2.7474097901 2.5628677163 -2.4729687601
O 0.665192139 3.1152773581 -1.7338499714
Listing S68. Coordinates of the transition state for forming the second intramolecular hydrogen
bond in complex 1
(I)
-CO2. (Corresponds to the structure labeled “TS 2” in Figure S49.)
247
H 2.38358 -0.43654 3.66332
C 1.73060 0.06001 2.98355
C 0.73973 0.96546 3.45243
H 0.63041 1.12769 4.50889
C -0.07194 1.60189 2.53326
H -0.86576 2.26339 2.83094
C 0.09530 1.31646 1.16282
N 1.04729 0.46396 0.70486
C 1.83246 -0.12164 1.59032
C -1.50297 1.02182 -0.62335
C -2.90983 1.09422 -0.66677
H -3.40626 1.82871 -0.05304
C -3.60433 0.18323 -1.42831
H -4.67831 0.17874 -1.46989
C -2.87668 -0.79749 -2.16911
H -3.38117 -1.50592 -2.77836
C -1.47013 -0.75152 -2.08219
N -0.79799 0.10310 -1.33854
N 1.30895 -0.54447 -3.10820
C 0.32654 -1.27327 -3.67211
C 0.32029 -1.64051 -5.01972
H -0.50587 -2.21466 -5.42494
C 1.36628 -1.20712 -5.82879
H 1.38095 -1.45654 -6.88751
C 2.39036 -0.45955 -5.27092
H 3.23673 -0.12940 -5.86175
C 2.33618 -0.17008 -3.89889
H 5.47541 -1.06427 1.20535
C 5.08028 -0.72321 0.25429
C 3.69886 -0.61339 0.06915
N 3.13847 -0.17150 -1.07636
C 3.97250 0.14116 -2.09415
C 5.37134 0.09685 -1.97777
H 5.99287 0.36463 -2.82399
C 5.92196 -0.34314 -0.78492
H 7.00209 -0.39865 -0.66508
N -0.74590 -1.68039 -2.85421
N 3.41342 0.49453 -3.31556
H 4.08071 0.84661 -3.98455
N 2.84514 -0.97710 1.12201
N -0.81217 1.87934 0.24916
H -0.79422 2.84668 0.08350
Co 1.18986 0.15492 -1.25530
H 3.34440 -1.43907 1.87163
C 1.32890 2.11991 -1.91216
O 0.99696 2.53341 -3.01787
O 1.83476 3.05493 -1.00950
H 1.85553 3.92380 -1.48595
Listing S69. Coordinates of the transition state for forming the singly hydrogen-bonded
intermediate in complex 1
(II)
-CO2H. (Corresponds to the structure labeled “TS 1” in Figure S51.)
248
H 2.2320009402 -0.5642570636 3.6600214694
C 1.5964889441 -0.0118384487 2.9744655196
C 0.58718072 0.815601505 3.439827171
H 0.4086098877 0.9177262249 4.5060119603
C -0.1841280069 1.5228136031 2.5149345271
H -0.9830102011 2.1902570267 2.8140448316
C 0.0695959665 1.3538275595 1.1614113561
N 1.0528134021 0.539938875 0.6875506751
C 1.8130316551 -0.107225346 1.5915314991
C -1.4828838531 1.0909180826 -0.593803842
C -2.869404963 1.089112824 -0.5378842539
H -3.3646949855 1.8310692862 0.0764629873
C -3.5741970506 0.1210580488 -1.2572194489
H -4.6591523872 0.088249959 -1.2278234145
C -2.865826798 -0.7946034375 -2.0187809046
H -3.3760740682 -1.551719266 -2.6064452137
C -1.4656664016 -0.7125414288 -2.051633279
N -0.7729989739 0.1956403963 -1.3372740745
N 1.3225974947 -0.52383232 -3.1139032895
C 0.3156196818 -1.2309559478 -3.6728101273
C 0.2934310529 -1.5978677658 -5.0185230883
H -0.5497808493 -2.1514203145 -5.4183358876
C 1.3446814308 -1.1925285401 -5.8370007398
H 1.3455417734 -1.4407634981 -6.8938903072
C 2.3930080082 -0.4753619157 -5.2829246244
H 3.2453172293 -0.1692149647 -5.8804253084
C 2.358463676 -0.184495784 -3.9133648583
H 5.4750187709 -1.0091344261 1.23469531
C 5.0878704118 -0.6877545818 0.2734329466
C 3.7100060834 -0.5715665107 0.0780517754
N 3.1579370278 -0.1474442844 -1.0826776052
C 4.0056364584 0.1209064441 -2.1055058216
C 5.4000476891 0.0705348714 -1.9764472859
H 6.0305676957 0.3072703702 -2.8271746462
C 5.9424086205 -0.3389440149 -0.7679517614
H 7.0188214863 -0.3974979185 -0.6390698264
N -0.7521171108 -1.6124140772 -2.8479798912
N 3.4643877819 0.4286716531 -3.3408588991
H 4.1356822799 0.7729611317 -4.0150418184
N 2.8539602693 -0.914490602 1.1292512441
N -0.7657470606 2.012424924 0.2180764476
H -0.2029094136 2.6730252417 -0.3325090659
Co 1.2152647078 0.2234739032 -1.2776981839
H 3.3421936667 -1.3832832026 1.8826661202
C 1.4028796485 2.1705661638 -2.029149104
O 1.3671102773 2.5171094436 -3.1985934932
O 1.5359538116 3.2047795781 -1.0780970599
H 1.6083016441 4.0488128232 -1.576723624
Listing S70. Coordinates of the singly hydrogen-bonded intermediate in complex 1
(II)
-CO2H.
(Corresponds to the structure labeled “1 H-bond” in Figure S51.)
249
H 2.2741651629 -0.6143716613 3.6570701795
C 1.6211827208 -0.0583452542 2.9911392436
C 0.6113857157 0.7500472852 3.4855895196
H 0.4477407591 0.8345018790 4.5557635455
C -0.1853066929 1.4543246198 2.5815882070
H -0.9960127028 2.0977930845 2.9004973375
C 0.0467146267 1.3093139303 1.2199238879
N 1.0431856317 0.5259108806 0.7163531255
C 1.8185173297 -0.1287863766 1.6034536456
C -1.5237885575 1.0535849851 -0.5260662737
C -2.9104932051 1.0191510245 -0.4549509325
H -3.4098618364 1.7198148753 0.2028643820
C -3.6063120815 0.0714255885 -1.2064332029
H -4.6898766671 0.0135029752 -1.1653159465
C -2.8861219982 -0.7963974924 -2.0102973853
H -3.3850749625 -1.5432269007 -2.6204679314
C -1.4882895410 -0.6817993525 -2.0557134973
N -0.7998824411 0.2178915014 -1.3247543726
N 1.3160394019 -0.4915677471 -3.1405398048
C 0.2874648637 -1.1664270391 -3.7068282534
C 0.2433301784 -1.5137396799 -5.0573336675
H -0.6225545294 -2.0310812948 -5.4570150405
C 1.3024299509 -1.1368455037 -5.8796079428
H 1.2850896490 -1.3660787034 -6.9406646206
C 2.3856987815 -0.4841948746 -5.3185443164
H 3.2564354101 -0.2218521114 -5.9102237291
C 2.3765747562 -0.2200659056 -3.9393274622
H 5.4738642033 -0.9272996626 1.2700574848
C 5.0945383373 -0.6302330868 0.2979703120
C 3.7190925925 -0.5513331864 0.0796301671
N 3.1688420902 -0.1547874386 -1.0933273252
C 4.0271168622 0.0876670998 -2.1143006317
C 5.4229906014 0.0887444558 -1.9586713932
H 6.0580703753 0.3186504543 -2.8077424689
C 5.9576591932 -0.2716439417 -0.7349237029
H 7.0329837379 -0.2923446792 -0.5867957686
N -0.7818885281 -1.5488114478 -2.8898019965
N 3.5310841439 0.2785886367 -3.3821467509
H 4.1862875100 0.6756608569 -4.0418003769
N 2.8622296124 -0.9187726199 1.1230618622
N -0.8318851160 1.9574140722 0.3172664983
H -0.3446760587 2.6847343382 -0.2311979332
Co 1.2152711080 0.2740082802 -1.2804070930
H 3.3588532614 -1.3894775002 1.8697410485
C 1.5590232067 2.2805972355 -1.9304225307
O 2.3906400415 2.6550436416 -2.7428034444
O 0.7679207139 3.3231905299 -1.3930408099
H 1.0681141868 4.1644266992 -1.8026137749
Listing S71. Coordinates of the barrier for intramolecular proton transfer in 1
(II)
-CO2H.
(Corresponds to the structure labeled “TS 2” in Figure S51.)
250
H 2.1950781138 -0.6996764063 3.6430549847
C 1.5879650204 -0.1073370149 2.9650202028
C 0.5659617916 0.7002867429 3.4356664831
H 0.347650975 0.745191725 4.4983989594
C -0.1668146938 1.4691624656 2.5265375381
H -0.9719605093 2.1270888296 2.8353698695
C 0.142508835 1.3669590371 1.1791956666
N 1.1227442456 0.5580969225 0.6920415646
C 1.8518023464 -0.1352286162 1.5863375109
C -1.4083897299 1.1634212823 -0.5620911787
C -2.7886159922 1.1522733463 -0.4309858896
H -3.2625873668 1.8824168633 0.2160728749
C -3.5152734252 0.1774300143 -1.1211456223
H -4.5969306902 0.1330551243 -1.0368864747
C -2.8380064577 -0.7257615766 -1.9233496284
H -3.369802563 -1.4844530871 -2.4896332955
C -1.4405351927 -0.6351798496 -2.0210315958
N -0.722169391 0.2726725354 -1.3324456227
N 1.3448679789 -0.5118608786 -3.1210322986
C 0.311241361 -1.1844111026 -3.6746754812
C 0.2701721105 -1.5522131466 -5.0199701792
H -0.5939112836 -2.0762028495 -5.4149895001
C 1.3314923173 -1.1864962657 -5.8436117172
H 1.3191599752 -1.4370211277 -6.899879116
C 2.4065601619 -0.5053431842 -5.2955040536
H 3.2662977276 -0.2300897717 -5.8973373041
C 2.3874401121 -0.2089206596 -3.9267956342
H 5.5169694127 -1.0365725333 1.221010859
C 5.1312751653 -0.7199312045 0.2576178515
C 3.7540243221 -0.5891906021 0.0654575688
N 3.2036084064 -0.1662205179 -1.0975755499
C 4.0524925007 0.0753149797 -2.1267466948
C 5.4466405933 0.0072698747 -2.0012974437
H 6.0772625088 0.2242677213 -2.8571833435
C 5.987367262 -0.3933210764 -0.7893826711
H 7.0632961025 -0.463702417 -0.6624983939
N -0.7636385193 -1.5333834532 -2.8473551247
N 3.5146913425 0.3733725615 -3.364836693
H 4.189601135 0.6983924285 -4.0448656619
N 2.9026487478 -0.923885568 1.1215632692
N -0.6377313232 2.0831710686 0.2177480953
H 0.0018870169 2.6368890718 -0.3689516042
Co 1.2714606456 0.2520286373 -1.2878013513
H 3.3866039544 -1.40662044 1.8686849326
C 1.5163084336 2.1867363157 -2.0630601424
O 1.5062780034 2.5276107556 -3.233771205
O 1.6596087817 3.2262078847 -1.1147340373
H 1.749249912 4.0670200531 -1.6160015092
O -2.5959085903 3.6082406113 1.7839830598
H -1.8623633102 3.4188960623 1.1644735335
H -2.7145036596 4.5697932278 1.8024389843
Listing S72. Coordinates of the singly hydrogen-bonded intermediate in complex 1
(II)
-CO2H in
the presence of an explicit water molecule. (Corresponds to the structure in Figure S52.)
251
H 2.5615110986 -0.2793201881 3.7212599696
C 1.8502210986 0.1870298119 3.0499599696
C 0.8418610986 1.0054298119 3.4955399696
H 0.7075110986 1.1931398119 4.5578399696
C -0.0249289014 1.5950198119 2.5594299696
H -0.8589289014 2.2180498119 2.8669299696
C 0.1691710986 1.2950198119 1.2181799696
N 1.1704210986 0.5209998119 0.7414599696
C 2.0672310986 -0.0099901881 1.6508899696
C -1.4466089014 0.9453098119 -0.5667800304
C -2.8393089014 1.0604798119 -0.7036500304
H -3.3687789014 1.8494698119 -0.1793200304
C -3.5121289014 0.1220298119 -1.4683300304
H -4.5915389014 0.1734498119 -1.5791400304
C -2.7875389014 -0.8940801881 -2.0896100304
H -3.2761589014 -1.6375701881 -2.7112000304
C -1.3989989014 -0.9033301881 -1.9459700304
N -0.7231989014 -0.0035901881 -1.2036100304
N 1.3462810986 -0.6985501881 -3.0143700304
C 0.3692110986 -1.4801701881 -3.5117300304
C 0.3036310986 -1.8727901881 -4.8488500304
H -0.5173089014 -2.4915201881 -5.1970600304
C 1.2794010986 -1.3979401881 -5.7269700304
H 1.2444210986 -1.6631901881 -6.7798700304
C 2.2967510986 -0.5941501881 -5.2402100304
H 3.0950810986 -0.2327801881 -5.8798600304
C 2.3219110986 -0.2975401881 -3.8667700304
H 5.5841010986 -1.3480201881 1.0637299696
C 5.1768410986 -0.9775901881 0.1303899696
C 3.7974910986 -0.6119201881 0.1341699696
N 3.2065410986 -0.1752801881 -1.0344800304
C 3.9919510986 -0.0137701881 -2.1248300304
C 5.3574010986 -0.2631101881 -2.1495600304
H 5.9194110986 -0.1078101881 -3.0638100304
C 5.9529010986 -0.7753201881 -0.9862400304
H 7.0140110986 -1.0116601881 -0.9741000304
N -0.6436389014 -1.8814001881 -2.6181300304
H -1.2460289014 -2.5780401881 -3.0410100304
N 3.3700810986 0.3982198119 -3.3206000304
H 3.9921510986 0.8792798119 -3.9620800304
N 3.1891910986 -0.6615701881 1.3279299696
N -0.7661389014 1.7957498119 0.2835499696
H -1.3597389014 2.5125398119 0.6815399696
Co 1.2762910986 0.1218798119 -1.1821500304
H 1.9008210986 3.8371498119 -2.0939000304
C 1.1895710986 2.0484498119 -1.9994500304
O 2.2248610986 2.9900298119 -1.7144100304
O 0.2840610986 2.4902798119 -2.6952700304
O 4.5304710986 2.9804698119 -3.4534500304
C 5.5761653228 3.8065890118 -3.0047897236
H 3.7936510986 2.9474598119 -2.8015100304
C 5.4677163223 5.2110958268 -3.5911581496
F 5.4430184255 5.1987301396 -4.9420051049
F 6.5341341544 5.9676291360 -3.2115970937
F 4.3492056864 5.8528116338 -3.1746310579
H 6.5283105326 3.3823911767 -3.3432438159
H 5.6061746279 3.9031724827 -1.9129735341
Listing S73. Coordinates of 1
(II)
-CO2H in the presence of an explicit TFE molecule.
(Corresponds to the structure in the blue box of main text Figure 5.)
252
Appendix 5.1: Calculated coordinates for 1-4
253
H 2.6531149082 -0.0459648438 3.8042095086
C 1.8802575343 0.3258089803 3.1384844641
C 0.8416279979 1.1155116133 3.6173143569
H 0.7714444308 1.3559195348 4.6736185868
C -0.1053557081 1.5921168413 2.7174228702
H -0.9439989698 2.1940860569 3.053483458
C 0.0179860588 1.2511755879 1.366937501
N 1.0224146784 0.4870008547 0.8732531388
C 1.9382679359 0.0459368643 1.7689239164
C -1.6582900848 0.9933198856 -0.4678836602
C -3.0477144189 1.1516378022 -0.5541280275
H -3.5661380024 1.8363882598 0.1096657752
C -3.7436903414 0.3732064212 -1.4724286722
H -4.8231899241 0.4592027583 -1.5550039788
C -3.0484610321 -0.5161163029 -2.2841309658
H -3.5621565862 -1.1191151219 -3.0263263454
C -1.6542219417 -0.5786511588 -2.1587907163
N -0.9654504156 0.1532737926 -1.2615157273
N 1.2356715973 -0.5031504636 -3.0899791258
C 0.2157281632 -1.1305833001 -3.7242886477
C 0.2492209915 -1.4951718096 -5.0743232708
H -0.6073772541 -1.9829314349 -5.5294717196
C 1.3784321644 -1.1853630364 -5.8232906781
H 1.4331616648 -1.4470539362 -6.875478811
C 2.4359185552 -0.5326978567 -5.2002272875
H 3.3434110254 -0.2927436285 -5.7455940903
C 2.3279677311 -0.220799366 -3.8409773894
H 5.6391348383 -0.893048241 1.2996321718
C 5.2038844571 -0.6216906719 0.3430154201
C 3.8155705788 -0.4948024603 0.2024803682
N 3.2249698203 -0.1538425224 -0.9600508376
C 4.0172607287 0.0914632196 -2.0219524604
C 5.4159046187 0.0294819655 -1.9605724272
H 6.0158749931 0.2293848131 -2.8426959563
C 6.0058516146 -0.3424307108 -0.7579230222
H 7.0866022314 -0.4154194823 -0.6787660934
N -0.9435420879 -1.4450790576 -2.9952570684
H -1.5678732915 -2.0323103585 -3.5344854186
N 3.4145862037 0.4328265298 -3.2362431605
H 4.1012298179 0.7181640001 -3.9236453261
N 3.0041322302 -0.7464928171 1.3129815828
N -0.9527398336 1.7443994675 0.477837122
H -1.5491114933 2.4285450549 0.9270578407
Co 1.1286746352 -0.000247283 -1.1083033484
H 3.5394791799 -1.123054439 2.0856261513
Listing 1. Coordinates of 1
(II)
254
H 2.7520119134 -0.264201131 3.8069033388
C 2.0264132237 0.184614515 3.1365526705
C 1.0889537646 1.1041623263 3.5993927935
H 1.0561533675 1.3739822708 4.6505604509
C 0.1941583701 1.6673755964 2.7004831959
H -0.5713107091 2.3640847266 3.0268052821
C 0.2623267488 1.2830877492 1.3570028989
N 1.1896638226 0.4210096421 0.8824057986
C 2.0502434621 -0.1167440231 1.7743123628
C -1.3552823341 0.9688019372 -0.4517501335
C -2.7411805844 1.1021990848 -0.5867329744
H -3.2725190757 1.8522226017 -0.0098119229
C -3.413497787 0.2312197559 -1.4325420302
H -4.490181375 0.3023790261 -1.5527948554
C -2.6893169563 -0.7362751912 -2.1238469312
H -3.1774973744 -1.4221277897 -2.8084711329
C -1.3039747148 -0.7756169977 -1.9618007383
N -0.6310513627 0.0602536636 -1.1420311276
N 1.4762855802 -0.5350731156 -2.9272159962
C 0.5190138921 -1.2975198713 -3.4997514214
C 0.54130586 -1.6689320075 -4.8446412136
H -0.2602763852 -2.2741387485 -5.2556087709
C 1.5785422211 -1.2027734212 -5.6471569774
H 1.6132693974 -1.4556947051 -6.7024362221
C 2.5686431263 -0.4117492 -5.0806971473
H 3.4076292667 -0.0521997687 -5.6673046017
C 2.4940929089 -0.1217229503 -3.7142428777
H 5.660960255 -1.0982019256 1.3326810839
C 5.2514208826 -0.7312724716 0.3971208498
C 3.8699440074 -0.6319276204 0.2285266972
N 3.2939700265 -0.1714525366 -0.9035136718
C 4.1148628325 0.2020735344 -1.9105815859
C 5.5099404084 0.1768697208 -1.8065091618
H 6.1222772706 0.490686018 -2.6456424404
C 6.0808832445 -0.3029624597 -0.6358941659
H 7.1603589125 -0.3478810542 -0.5284515736
N -0.5461801813 -1.7106336658 -2.6846343951
H -1.1351568414 -2.3889836093 -3.153788893
N 3.5279851163 0.5916638868 -3.1114849765
H 4.1878678031 0.9797361818 -3.7743276015
N 3.0143797454 -1.007158444 1.2766391648
N -0.6800541849 1.7772304308 0.4595776727
H -1.2581447003 2.5118315728 0.8483048988
Co 1.3435117935 0.1031427372 -1.0609947222
H 3.5199678961 -1.4687907381 2.024075631
C 1.4450011032 2.0885736401 -1.5904678545
255
O 0.8182609905 2.6351266091 -2.4873834552
O 2.3239129814 2.8670808188 -0.8429579521
H 2.2756623714 3.7808554 -1.2007852661
Listing 2. Coordinates of 1
(II)
-CO2H
H 2.7547119474 0.0014664028 3.7144940191
C 1.9484363364 0.3431411284 3.0719466755
C 0.9469623064 1.1793389512 3.5566877708
H 0.93941487 1.4860934692 4.5987245396
C -0.0418059372 1.6171049803 2.6851395437
H -0.8520369428 2.2547521506 3.0266931838
C 0.003841933 1.1912965285 1.3489165579
N 0.9775386052 0.3988196846 0.854292244
C 1.9285506295 -0.0081867615 1.7170175421
C -1.6640350527 0.8890153399 -0.4979937322
C -3.0457619885 1.0809795875 -0.6507171177
H -3.5730813219 1.7799891233 -0.0080229751
C -3.7177679377 0.3373894988 -1.6119093364
H -4.7880566119 0.4571788737 -1.753759075
C -2.9965747106 -0.5618165152 -2.3922413676
H -3.4804753052 -1.1418743177 -3.1727568868
C -1.6152776008 -0.6642226375 -2.1898699299
N -0.9433763278 0.0403958887 -1.2595225586
N 1.2678560388 -0.6073179395 -3.1569598054
C 0.232207386 -1.211177399 -3.7713967494
C 0.212826934 -1.517764176 -5.1371388831
H -0.6610910276 -1.9856667819 -5.5813582762
C 1.3106699115 -1.1597755641 -5.9140682255
H 1.3236490156 -1.3663455161 -6.9804511425
C 2.3885385977 -0.5311055769 -5.3043429748
H 3.2721246818 -0.2535246485 -5.8714725413
C 2.3313201072 -0.2881292906 -3.9234155855
H 5.5834787171 -0.7896099723 1.2950621782
C 5.1654103316 -0.5664844503 0.3177098972
C 3.7784292391 -0.5372408198 0.1323254475
N 3.1889685393 -0.2447814363 -1.0428383093
C 4.0024823736 0.0353923165 -2.0815571281
C 5.4022167202 0.0603514441 -1.9817412197
H 6.007351717 0.2923767477 -2.8531591926
C 5.9865307228 -0.2505201203 -0.7609599692
H 7.0670707377 -0.2455299795 -0.6493832662
N -0.8907071987 -1.5639172935 -2.9969165956
H -1.5271694406 -2.1300398185 -3.5447349276
N 3.4385211055 0.3083321537 -3.3252487879
H 4.1215084043 0.625156377 -4.0001104458
N 2.9541124258 -0.8439045725 1.2332381804
N -1.0173112386 1.6126001857 0.5007678476
256
H -1.617179824 2.3048153029 0.9286155143
Co 1.1394652475 0.1081104718 -1.202725299
H 3.5134738738 -1.1920457119 2.0025012632
C 1.3053314379 2.1021962851 -1.6908468203
O 2.1219003049 2.6942356744 -0.9676885854
O 0.5651072682 2.4124827329 -2.6376746956
Listing 3. Coordinates of 1
(I)
-CO2
H 2.6202112978 -0.3538696077 3.5274237972
C 2.018013369 0.1972220123 2.8124665842
C 1.2172153336 1.2589983024 3.2164576302
H 1.1694898679 1.5405099902 4.264049072
C 0.4708686516 1.9530913373 2.2675288292
H -0.1882536552 2.7657813679 2.5548018977
C 0.5425129695 1.54210857 0.9385946796
N 1.351634923 0.5375320131 0.5182434947
C 2.0792161891 -0.1189901953 1.4529621329
C -1.1075093524 1.3477831571 -0.827367611
C -2.4754350433 1.604381311 -0.8830945878
H -2.8981448713 2.4428694426 -0.3393455087
C -3.2846258816 0.7282987867 -1.6021587915
H -4.3573720043 0.8887954703 -1.6515116989
C -2.7086143471 -0.3588075529 -2.2491232207
H -3.3125872478 -1.0519390575 -2.8255227279
C -1.3220250115 -0.5195173707 -2.1887071565
N -0.5215843215 0.3174879682 -1.486222252
N 1.4459976743 -0.7025183873 -3.2147149908
C 0.4007746561 -1.4128406653 -3.7017489626
C 0.403355469 -1.9719027878 -4.9821394711
H -0.4561513888 -2.5335661984 -5.333238714
C 1.5001110643 -1.7488428141 -5.8063992512
H 1.5175243503 -2.1513056759 -6.8147638916
C 2.5797330503 -1.0122564018 -5.3255562356
H 3.464020188 -0.8489090036 -5.9330342022
C 2.5257477972 -0.5350185151 -4.0180863389
H 5.4849524182 -1.8166824362 1.0229146453
C 5.1369272149 -1.403391618 0.081932782
C 3.8044610281 -1.0075948007 -0.0594865936
N 3.3182779713 -0.480896767 -1.2086395299
C 4.175709672 -0.3400332664 -2.2503842439
C 5.5287394754 -0.6612162686 -2.1689779477
H 6.1761676436 -0.5260772789 -3.0291966033
C 6.0094270622 -1.2086097536 -0.982267231
H 7.0551481342 -1.4861927945 -0.8908638685
N -0.7177801216 -1.5721454934 -2.8801486217
H -1.3915577883 -2.2281799788 -3.2597538925
N 3.6280537308 0.1288666673 -3.4555623615
257
H 4.3388999399 0.3543597788 -4.1438248787
N 2.9274062615 -1.1408715295 1.0195399381
N -0.2637736499 2.1477552036 -0.0387549869
H -0.7285999004 2.9826359224 0.3030792097
Co 1.4379955974 0.0862310266 -1.4031721181
H 3.3303134817 -1.6658723061 1.7878721409
C 1.8874469489 2.029822924 -2.03837097
O 2.1289711539 3.0837772735 -2.3785573742
Listing 4. Coordinates of 1
(II)
-CO
H 2.6688816906 -0.012665488 3.8809418351
C 1.8783491884 0.3374291854 3.2217594099
C 0.7811323178 1.039180801 3.7253905909
H 0.6802602068 1.2301445162 4.7889663839
C -0.1864955669 1.491746799 2.8153647338
H -1.0684089087 2.0269134714 3.1571501957
C -0.0300630345 1.2070354144 1.4622586156
N 1.0372923393 0.5287529128 0.9402056463
C 1.9825943029 0.1287042061 1.8442342816
C -1.6353017186 0.9783071697 -0.4563640013
C -3.0033826978 1.2141833986 -0.6685706635
H -3.5312896512 1.9182171769 -0.0304506414
C -3.6701612876 0.5061942566 -1.6578735013
H -4.7318347033 0.6551489823 -1.8306493405
C -2.9396282334 -0.4207964982 -2.4161850276
H -3.4093551965 -0.991811118 -3.2117094454
C -1.5845219924 -0.5901839741 -2.1443512674
N -0.8984420946 0.1045392138 -1.1995894618
N 1.2393089516 -0.5295050254 -3.070262853
C 0.2346195659 -1.212150856 -3.6764060095
C 0.2417665512 -1.568181338 -5.0241567079
H -0.6093613101 -2.0917208259 -5.4510509052
C 1.3390149878 -1.2075445407 -5.8133658691
H 1.377919258 -1.4684882641 -6.8664882824
C 2.3840057425 -0.5013550613 -5.2105249604
H 3.2693261048 -0.2202247282 -5.7740709858
C 2.2946322199 -0.1904368425 -3.852801324
H 5.6840128617 -0.8506470352 1.222953055
C 5.2258706895 -0.60138998 0.2692558907
C 3.8348160717 -0.3885602746 0.200842484
N 3.1820640503 -0.0575731912 -0.9525628844
C 3.9661102213 0.1005787945 -2.0492593619
C 5.3475558559 -0.0849934021 -2.065518765
H 5.9025744807 0.0346584167 -2.9911635648
C 5.9935447433 -0.4426668837 -0.8706908493
H 7.0700754918 -0.5828099081 -0.8406871805
N -0.8638867751 -1.5670968956 -2.8701492695
258
H -1.5014914856 -2.1619835514 -3.3862419727
N 3.340470309 0.5202365888 -3.2422950617
H 4.0340306409 0.795879033 -3.9269937798
N 3.1147514512 -0.5376251564 1.3797626866
N -1.009648909 1.6757891047 0.5755120848
H -1.651677923 2.3063124123 1.0376268947
Co 1.1367223592 0.0194004267 -1.0455710766
H 3.7017188344 -0.8488514425 2.1419902256
Listing 5. Coordinates of 1
(0)
H 2.6251490235 -0.0985123505 3.8692623073
C 1.8602651983 0.2745356092 3.1963939278
C 0.8184004199 1.0700073692 3.663790216
C 0.7231156052 1.3634667826 5.1492474931
C -0.1266140407 1.566786526 2.7765124032
H -0.9588608517 2.1684526682 3.1233354819
C -0.001186737 1.2238142935 1.4225641339
N 1.0059815608 0.4687311251 0.9473454419
C 1.9241775618 0.0142590096 1.8234649171
C -1.6266692316 0.929566026 -0.4499352516
C -3.0132012024 1.0649656474 -0.534695707
H -3.5440059992 1.7234443334 0.1452742622
C -3.7009862197 0.3063276876 -1.4771584905
C -5.2042513195 0.4388921577 -1.5894183219
C -2.9858111556 -0.5475729103 -2.3059505677
H -3.4876970722 -1.1374832936 -3.0646494658
C -1.5948747517 -0.6026272011 -2.1685035889
N -0.8985703226 0.1134017525 -1.2534620269
N 1.2535880408 -0.4977317204 -3.1512504666
C 0.2381876386 -1.1260522289 -3.7785201516
C 0.2724609433 -1.4625591822 -5.1350894844
H -0.5697609213 -1.957317908 -5.6073347928
C 1.3953006711 -1.0958493948 -5.8722433642
C 1.4453616392 -1.4294191318 -7.351515909
C 2.4446165142 -0.4330294765 -5.2530419969
H 3.3375282996 -0.1618715818 -5.8042637522
C 2.3380797353 -0.1709825482 -3.8782062578
H 5.5928831721 -0.779824486 1.3291946523
C 5.1573845645 -0.5301478954 0.3671490836
C 3.7733355998 -0.4583462205 0.2134613901
N 3.1602081287 -0.1326259465 -0.9540392143
C 3.9734254375 0.1323911124 -2.0041792192
C 5.3713637018 0.1039815234 -1.9335342112
H 5.9728620701 0.3133380543 -2.8108840151
C 5.9665263804 -0.2368699946 -0.7276629621
C 7.4708696855 -0.2886957118 -0.5750942028
N -0.8959659231 -1.4598015152 -3.033323246
259
H -1.5284155764 -2.0509389564 -3.55944279
N 3.4057664924 0.4619242183 -3.2434011611
H 4.1060981289 0.7777124401 -3.9035280699
N 2.9799832274 -0.7573053892 1.3339093653
N -0.9620861192 1.6918651813 0.5244253183
H -1.582428231 2.3671200742 0.9549214994
Co 1.1315787575 -0.0220716809 -1.0990969347
H 3.5313949465 -1.1584709758 2.0832296547
F -0.2404144916 2.2635324896 5.4252756482
F 1.8924197679 1.8491948776 5.6200124821
F 0.4464229036 0.2349368353 5.8396087516
F 8.1070094728 -0.0202564935 -1.7328396069
F 7.8714476943 -1.5100974696 -0.1554347764
F 7.8911972825 0.6089219734 0.345318274
F 2.5923616388 -1.0168821927 -7.9246381145
F 0.4193401599 -0.842507585 -8.0065174814
F 1.3402673253 -2.7625162114 -7.5446477137
F -5.7233803257 -0.4393705633 -2.4703177086
F -5.5483201702 1.6824965002 -1.9952006061
F -5.8004287276 0.2287119475 -0.394105074
Listing 6. Coordinates of 2
(II)
H 2.6411272046 -0.330833012 3.5244969714
C 2.0292664585 0.2067463057 2.8076576
C 1.2320694249 1.2741391635 3.2070213836
C 1.1645422 1.6520062161 4.6822555955
C 0.4784283655 1.9624023731 2.2622318489
H -0.171352142 2.7808476196 2.5525540722
C 0.540746972 1.5394964403 0.9356311552
N 1.3467535353 0.533446819 0.5163886016
C 2.0785822944 -0.118726199 1.4517333605
C -1.1143102549 1.3340734499 -0.822853226
C -2.4824032108 1.5790566273 -0.8665564576
H -2.913420253 2.4084424074 -0.3153384706
C -3.2884987316 0.6952966803 -1.5828146433
C -4.7930032562 0.9343442927 -1.632295112
C -2.7124555898 -0.3835336253 -2.237708564
H -3.319158844 -1.0769520634 -2.8094591183
C -1.3223197218 -0.5302098269 -2.1877586941
N -0.5238445892 0.3093215247 -1.4889943135
N 1.4479896475 -0.7074624811 -3.2175932614
C 0.3988720966 -1.410988196 -3.7095410548
C 0.396682712 -1.9597701651 -4.9915693682
H -0.4645403132 -2.5138340155 -5.3507807591
C 1.4952774509 -1.7329166461 -5.8148145766
C 1.486232275 -2.2920265037 -7.232680911
C 2.5792239277 -1.0084552917 -5.333037635
260
H 3.4608794637 -0.8488443658 -5.9441198713
C 2.5271578458 -0.5422031023 -4.0196531299
H 5.4824987366 -1.8132980337 1.0333254644
C 5.131316617 -1.405988029 0.0908996208
C 3.801230935 -1.0127615353 -0.0560940414
N 3.3168883039 -0.4888181448 -1.2089642422
C 4.1760746158 -0.352460672 -2.2476002267
C 5.5312180758 -0.6705711301 -2.1631921702
H 6.1857594082 -0.5391083049 -3.0176162868
C 6.0052020212 -1.2121743182 -0.9741750388
C 7.4663288193 -1.6188829512 -0.822260401
N -0.7210443137 -1.5732587269 -2.8916435706
H -1.3926461694 -2.2336881296 -3.2688096736
N 3.6380045006 0.1041321081 -3.459386954
H 4.3504011249 0.3301502021 -4.1464673953
N 2.922840636 -1.144151519 1.0211446308
N -0.2749491456 2.138521456 -0.0351902914
H -0.7387272625 2.976058742 0.3029390713
Co 1.436199107 0.0794170344 -1.4050628892
H 3.318076543 -1.6768446037 1.7888928468
C 1.8872307549 2.0322725601 -2.0430427172
O 2.1300468154 3.0836177137 -2.3872123522
F 0.6651259015 2.8880851426 4.8441926367
F 2.3905459413 1.6085607167 5.2337331288
F 0.3740160913 0.7833726907 5.3413201768
F 8.1862770341 -1.2739619819 -1.901760946
F 7.5559961295 -2.9519935631 -0.6570943073
F 8.0024735356 -1.0238708146 0.2592023816
F 2.6188387779 -1.9924554691 -7.8873988937
F 0.4461625006 -1.7813678388 -7.9187420127
F 1.3514105305 -3.6306170678 -7.1989829926
F -5.4273544661 -0.0631311022 -2.2680889293
F -5.0519297586 2.0879040361 -2.2757663447
F -5.2866873091 1.0284471079 -0.3834687034
Listing 7. Coordinates of 2
(II)
-CO
H 2.7340020085 -0.2825488539 3.7455009031
C 2.0101384461 0.1689271215 3.0757013514
C 1.0762776089 1.0927745366 3.5423850544
C 1.0505062532 1.4384518702 5.0181698804
C 0.1817121645 1.6665751181 2.6535751115
H -0.5768409433 2.3633744376 2.9910739966
C 0.2467288495 1.2868749533 1.3074969762
N 1.1665060898 0.4224970346 0.8266026806
C 2.0267589272 -0.1257065509 1.7149171717
C -1.3747649077 0.9933231177 -0.4983546283
C -2.7573179797 1.1364022764 -0.6306321988
261
H -3.2889268306 1.8819097325 -0.048738482
C -3.4325730905 0.2740275195 -1.4852762587
C -4.9367573503 0.3993487822 -1.6317976765
C -2.7194618719 -0.6928265563 -2.1841111921
H -3.2152823374 -1.3653414046 -2.8743242824
C -1.333737077 -0.741409289 -2.0190897836
N -0.6556493944 0.0838305474 -1.1950121449
N 1.4442951435 -0.5143835714 -2.9836114926
C 0.4823779881 -1.2708859359 -3.5595881212
C 0.5045863618 -1.6420435249 -4.9019758125
H -0.2974661169 -2.2408973065 -5.3202166568
C 1.5499610323 -1.1809680588 -5.6992655483
C 1.5896649514 -1.5644808701 -7.1656707181
C 2.5421963377 -0.3944853038 -5.1357723919
H 3.3811844163 -0.0419354996 -5.7241832902
C 2.4634396036 -0.1052758858 -3.7684143124
H 5.6308252546 -1.1120293156 1.2676376517
C 5.2172970543 -0.7391216709 0.3367626214
C 3.8388228514 -0.6373167119 0.1671578527
N 3.2633924938 -0.167916632 -0.9631614596
C 4.0847882281 0.2079821966 -1.9669237259
C 5.4807933101 0.1802713331 -1.865632146
H 6.0979317942 0.4912457082 -2.7007037052
C 6.0455722396 -0.3056082711 -0.6967813195
C 7.5495438304 -0.3574020214 -0.5136878751
N -0.5870153318 -1.6769904025 -2.7490554561
H -1.1777723412 -2.3582915033 -3.2124186145
N 3.5027890616 0.6000658855 -3.1680802239
H 4.1615074541 0.9932906884 -3.8297876085
N 2.9820016868 -1.0203238512 1.2100455582
N -0.6963575198 1.7913824555 0.4189806595
H -1.2659194298 2.5326393841 0.8088930699
Co 1.3163328433 0.110417866 -1.1146565203
H 3.4795626467 -1.5026531066 1.9503564963
C 1.426954746 2.0903712262 -1.6336735021
O 0.799665593 2.6350924309 -2.5286953527
O 2.3085796947 2.8537598669 -0.8819889164
H 2.2719298204 3.7727574536 -1.2276583009
F 0.1259870785 2.3758337972 5.3008239752
F 2.2526704893 1.9030327216 5.4224109575
F 0.7712229198 0.3420345116 5.7579220564
F 8.2060628794 -0.0989092265 -1.6611245695
F 7.9383466476 -1.5747276998 -0.0760805037
F 7.9474365264 0.5495754096 0.405257732
F 2.620200851 -0.9843282384 -7.8091873768
F 0.4487912329 -1.2002052351 -7.7892646954
262
F 1.715102174 -2.9039304671 -7.3019050299
F -5.428106122 -0.4781691215 -2.5280268901
F -5.2781378971 1.6413401182 -2.0336345434
F -5.5519010424 0.1724019855 -0.4492684301
Listing 8. Coordinates of 2
(II)
-CO2H
H 2.5316304732 0.0182612862 3.7193134332
C 1.7850316806 0.4260537379 3.0454487675
C 0.7465391546 1.2120980118 3.5246802919
C 0.6581335531 1.5189401764 4.9960771611
C -0.1822200528 1.7355090332 2.6199080429
H -1.0295745939 2.320179218 2.9583023096
C -0.0158496717 1.4482009449 1.2650813033
N 0.9990274973 0.7041183914 0.7684180073
C 1.8828729368 0.2083903044 1.6640286631
C -1.6543898259 1.1006076723 -0.5268834765
C -3.039720811 1.0803392534 -0.4634398383
H -3.5668353647 1.6881410078 0.2640495639
C -3.7362508223 0.2291325416 -1.3418101852
C -5.2349098902 0.1714330605 -1.2859746468
C -3.0116754003 -0.548930297 -2.2282270271
H -3.5138220075 -1.2002272707 -2.9355636849
C -1.6108605885 -0.4431459507 -2.2374915144
N -0.915640928 0.3521277401 -1.3859423669
N 1.2808971273 -0.3251750009 -3.2534818188
C 0.2512987581 -0.9520715393 -3.8759843457
C 0.3115949204 -1.3884095734 -5.2109993496
H -0.5502391993 -1.8604260177 -5.6708793611
C 1.4616283256 -1.1454086156 -5.941216634
C 1.5798745128 -1.6196733185 -7.3639189377
C 2.5418523812 -0.5036477576 -5.3190023084
H 3.4676260527 -0.3193036097 -5.8519362146
C 2.4010918193 -0.1267431077 -3.9855495613
H 5.53356835 -0.9230214654 1.2129158837
C 5.1320869828 -0.6431812265 0.2450484898
C 3.7575429845 -0.3985129593 0.089046871
N 3.1988955082 -0.0239520484 -1.0835576235
C 4.0338705167 0.128106836 -2.1364084656
C 5.4149699685 -0.0617882398 -2.0670181538
H 6.0351394963 0.0732845514 -2.9460731203
C 5.966683296 -0.4553152305 -0.8443731932
C 7.4443666081 -0.7277989289 -0.7384445124
N -0.9349444746 -1.1938846617 -3.1943905427
H -1.5693471149 -1.7651360323 -3.7369073104
N 3.4842582003 0.5098857475 -3.3640128152
H 4.2008807811 0.765764871 -4.0318103329
N 2.9582777553 -0.5612734014 1.2188860318
263
N -0.9489987117 1.949851072 0.3483382549
H -1.5646280001 2.6298421756 0.7781820294
Co 1.1540551334 0.4697160585 -1.3194415223
H 3.4858836411 -0.9420035149 1.9937816303
C 1.418012038 2.5302345472 -1.8429167817
O 2.2424305548 3.0083496004 -1.0798806894
O 0.6993041056 2.7745659655 -2.7975744909
F -0.5725461077 1.9496652708 5.3564095247
F 1.539224633 2.4864453167 5.3619082126
F 0.9442628056 0.4304399654 5.7545282947
F 8.1745708626 0.1520821152 -1.4633714179
F 7.7537142315 -1.9675453518 -1.2054502949
F 7.886515556 -0.6704234258 0.5392512912
F 2.3423198323 -0.7899770552 -8.1147165658
F 0.3744625248 -1.7264585717 -7.9716653712
F 2.1609686691 -2.8495955474 -7.4327575811
F -5.7574493715 -0.674046181 -2.2048152368
F -5.7980349515 1.3901716541 -1.4940810654
F -5.6736363405 -0.2457322261 -0.0667656988
Listing 9. Coordinates of 2
(I)
-CO2
H 2.7603131773 -0.3452617686 3.8035442417
C 1.9583467364 0.0552958394 3.1965124805
C 0.8928335015 0.7832500734 3.7774546872
C -0.0732971555 1.3018762299 2.8816111406
H -0.944105227 1.8347090981 3.2420037835
C 0.0685340479 1.0787908819 1.5163903944
N 1.0834106276 0.3834658515 0.9618874572
C 2.005203136 -0.1075913857 1.8149905696
C -1.5658399943 0.9409922355 -0.3709748427
C -2.954839551 1.0918375792 -0.4510644255
H -3.479636675 1.7010246812 0.2785580861
C -3.6454177018 0.4205695379 -1.4537667782
C -2.9281482396 -0.3701593306 -2.3445939483
H -3.426529209 -0.8941727836 -3.1545714451
C -1.538185587 -0.4521889787 -2.2060933194
N -0.8423542019 0.1873694931 -1.2343719072
N 1.307758799 -0.2937995812 -3.161110354
C 0.3052032505 -0.889909953 -3.8391673217
C 0.3401400845 -1.1702421125 -5.2014817811
H -0.5281345178 -1.6131145809 -5.6724410271
C 1.4843901408 -0.8194747322 -5.9568324957
C 2.5327524019 -0.1847210816 -5.2481900537
H 3.4581928112 0.0844370079 -5.7409218383
C 2.3962805295 0.0452292853 -3.8829143605
H 5.6831882577 -0.8637649462 1.2472790353
C 5.2454934483 -0.5499036074 0.30445219
264
C 3.8555406852 -0.4663812666 0.1688664827
N 3.2360474528 -0.0669150728 -0.9691635216
C 4.0394370928 0.2644118755 -2.0093532825
C 5.437184467 0.2269528161 -1.9504083695
H 6.0266157727 0.4926045648 -2.8226631326
C 6.0475874684 -0.1905804264 -0.7731392143
N -0.8396252001 -1.2596381409 -3.1180248405
H -1.4779938497 -1.798250009 -3.6899398414
N 3.4490130786 0.686110335 -3.2110977242
H 4.1467483369 1.0298832265 -3.8591464812
N 3.0695934268 -0.8412114863 1.2706681883
N -0.8933602268 1.6258555728 0.6530607939
H -1.5182856778 2.2523174599 1.1447660758
Co 1.1976778561 0.0519878283 -1.1004282328
H 3.6354450429 -1.2651778962 1.9952443179
N 0.8012243856 0.9751519218 5.1230695902
N 1.5731132666 -1.0788658758 -7.2912830964
C 1.7776485043 0.3648873585 6.0211566804
H 2.7899184825 0.7435821438 5.8296379438
H 1.7849697763 -0.7284675549 5.9225749855
H 1.5167403321 0.6098059349 7.050793417
C -0.3083787901 1.7418343153 5.6829729028
H -0.3507254082 2.7495402927 5.2517099707
H -0.1647733353 1.8437272989 6.7588298254
H -1.2726141624 1.2438198212 5.512724348
C 2.7357840702 -0.6302629756 -8.0527924032
C 0.4939974562 -1.7820592784 -7.9800147103
H 3.6543957757 -1.1295456211 -7.7173808407
H 2.8726685056 0.4552795601 -7.9690249155
H 2.5857795172 -0.8697287172 -9.1056314352
H 0.2615385039 -2.7308060669 -7.48176499
H 0.8097161535 -2.0085321075 -8.9987102715
H -0.4207011119 -1.1755284459 -8.0318499331
H -4.7239736156 0.5115222986 -1.5389910358
H 7.1296330776 -0.2370766354 -0.6970554176
Listing 10. Coordinates of 3
(II)
H 2.654597128 -0.5311014114 3.7641814381
C 1.9057347101 -0.0803165365 3.1262302956
C 0.9394445033 0.822374526 3.6525124476
C 0.0671664279 1.4155435845 2.7000991337
H -0.7180879258 2.093207688 3.0085241436
C 0.1705568002 1.0817646161 1.3620181238
N 1.0826921573 0.2079174467 0.8655984502
C 1.9404982895 -0.3325580408 1.7695401922
C -1.4419137863 0.9265649298 -0.4902927384
C -2.8150303131 1.1497572162 -0.6334352543
265
H -3.3102251517 1.8942276943 -0.0184842774
C -3.5298829168 0.3709998254 -1.5350128653
C -2.8592766558 -0.5835416824 -2.2951202868
H -3.3811426313 -1.1862918036 -3.0312445586
C -1.4808222382 -0.7131573132 -2.1332226674
N -0.7738971015 0.0088120431 -1.2284103081
N 1.2841559936 -0.4403916383 -2.9874586405
C 0.335520912 -1.1123506442 -3.6902941745
C 0.3663847425 -1.3043329633 -5.0568404439
H -0.4539626183 -1.8251365348 -5.5329109765
C 1.4314927881 -0.753878316 -5.8234357059
C 2.4048131478 -0.021805328 -5.090460539
H 3.2626776774 0.4140540447 -5.5853403368
C 2.2957654991 0.094988105 -3.7167087974
H 5.5965310173 -1.1456643793 1.2510545988
C 5.1479868778 -0.7425049567 0.3491005183
C 3.7615414217 -0.7129097261 0.2077453186
N 3.1439855676 -0.2257189865 -0.8974649538
C 3.9184103484 0.2988706445 -1.8768627967
C 5.3127622111 0.3502593293 -1.7836514034
H 5.8960120752 0.7758056232 -2.5936139438
C 5.9296982207 -0.1947044924 -0.6643307762
N -0.7508859992 -1.6027683186 -2.9354029111
H -1.3519596874 -2.2154289097 -3.4758567097
N 3.2826673986 0.8032155407 -3.0113489082
H 3.9211433621 1.292909011 -3.6274941092
N 2.9326098738 -1.1820569316 1.2374718175
N -0.716029516 1.6666991128 0.4430732835
H -1.2659166967 2.4103518758 0.8572027841
Co 1.1715324271 -0.2980793583 -1.0311612186
H 3.4530854037 -1.6696135263 1.9587168834
N 0.8628583719 1.1011654241 4.9701737977
N 1.5078292392 -0.9086418321 -7.1615191426
C 1.7100367887 0.3865990031 5.9317551824
H 2.7682051066 0.6450911401 5.8024470134
H 1.5858546192 -0.6975100854 5.8317883425
H 1.4132767467 0.6664110864 6.9417543274
C -0.0881673159 2.1007506923 5.4684621455
H 0.0267111849 3.0494991132 4.9332063509
H 0.1137729733 2.2865779571 6.5226701963
H -1.1240610616 1.7516159849 5.3727554108
C 2.5781829822 -0.2573238488 -7.9248790743
C 0.5136713356 -1.717418562 -7.8757799767
H 3.5628530801 -0.6491298753 -7.6426958871
H 2.5629418265 0.8285550465 -7.7758754569
H 2.4275794649 -0.4532774306 -8.9856145471
266
H 0.4687366828 -2.7332468089 -7.4673625572
H 0.8029798217 -1.7897416015 -8.9232776877
H -0.4829112168 -1.2612676715 -7.8273471503
C 1.0261973825 -2.3370329346 -0.6860384622
O 0.9378307232 -3.4522360645 -0.4949725133
H -4.6005832549 0.5102098595 -1.6500635447
H 7.0120707757 -0.1869796512 -0.5779558947
Listing 11. Coordinates of 3
(II)
-CO
H 2.641556765 -0.4631110338 3.7549515281
C 1.8950288742 0.0016218652 3.1240515016
C 0.8920561758 0.8359129851 3.6676224643
C 0.0278189387 1.4544182176 2.7315714361
H -0.7859861943 2.0911502128 3.053323045
C 0.1765140197 1.1927963582 1.3777972643
N 1.1142671406 0.3689942749 0.8582126288
C 1.9698516888 -0.1837183146 1.7495096758
C -1.459009391 1.0496086967 -0.4345644657
C -2.8482750794 1.1853088645 -0.4640915442
H -3.3425375351 1.8781787427 0.2093763601
C -3.5766587693 0.380914185 -1.3368164446
C -2.8997463946 -0.5087627932 -2.1592631128
H -3.4292506814 -1.1362474905 -2.8693332739
C -1.5015376622 -0.5537949391 -2.0943087665
N -0.7807372001 0.2002765938 -1.2347694978
N 1.2657511937 -0.2940806973 -3.000455746
C 0.3166437595 -0.9779570119 -3.6804985975
C 0.3714179635 -1.2501153397 -5.0410272501
H -0.4573777575 -1.771222026 -5.5022188373
C 1.4664299899 -0.7888545797 -5.8063115728
C 2.4374858647 -0.0342870706 -5.1039675973
H 3.3198876952 0.3444141734 -5.6030850182
C 2.2965619748 0.1732411387 -3.7401359269
H 5.6327313574 -1.1579411608 1.1150310479
C 5.1823222591 -0.7231520719 0.2284537208
C 3.7923214286 -0.5710605997 0.1525808396
N 3.1691516286 -0.0386435948 -0.921728392
C 3.9427563553 0.3836985081 -1.9435790955
C 5.3366869826 0.3067013613 -1.9309056559
H 5.9100547162 0.6528841957 -2.7847394888
C 5.9603814365 -0.2684241043 -0.8268611382
N -0.8083651897 -1.3918380315 -2.9615173713
H -1.4149023382 -2.0054773121 -3.4903645597
N 3.2852271572 0.9134875721 -3.0634754288
H 3.9369268152 1.3403766417 -3.7114423212
N 3.0090787618 -0.9607875897 1.2349582306
N -0.7048000591 1.8112053379 0.4701851229
267
H -1.2719148794 2.516383699 0.9259654511
Co 1.1797813043 -0.1141654171 -1.0450840297
H 3.533849297 -1.451586758 1.947658339
N 0.7711819695 1.0402176595 5.0080550279
N 1.5795201543 -1.0441584412 -7.1383159387
C 1.6112411245 0.2931596692 5.9412714861
H 2.6726709485 0.5429454618 5.8150193385
H 1.4841813165 -0.7894909939 5.8128689602
H 1.3254887748 0.549174516 6.961523489
C -0.2556890634 1.9388547276 5.5284986544
H -0.1786068803 2.9322126623 5.070841968
H -0.1143646144 2.0564151723 6.6030914249
H -1.2675196284 1.546012274 5.3568701937
C 2.6756373279 -0.461339793 -7.908548613
C 0.5757853836 -1.8563722961 -7.8211583407
H 3.6490384698 -0.8420948933 -7.5726012825
H 2.6786086655 0.6338081906 -7.8344358152
H 2.5536324388 -0.7266487131 -8.958760445
H 0.4258277507 -2.8104867718 -7.3031175375
H 0.9227077956 -2.0763755333 -8.8310689356
H -0.3895552167 -1.3361570336 -7.8953983946
C 1.0871850009 -2.1394513168 -0.7333073555
O 0.1242313126 -2.5679798028 0.1808037138
O 1.7832819294 -2.9966641696 -1.261704104
H 0.1935598198 -3.5469430521 0.2262645504
H -4.6598708981 0.4489213783 -1.3732844919
H 7.041773706 -0.3617745889 -0.7927210762
Listing 12. Coordinates of 3
(II)
-CO2H
H 2.806204717 -0.5819037417 3.6457518651
C 2.0292843987 -0.0641028397 3.0977835308
C 0.8882138207 0.4463352139 3.7448080572
C -0.0375850116 1.1386318496 2.93436103
H -0.9620339966 1.5308467214 3.3385506018
C 0.2031336416 1.2462163757 1.5651561738
N 1.2670186831 0.7257458149 0.9347135523
C 2.1682506873 0.1068297656 1.7173767065
C -1.4322643289 1.5250009383 -0.3164177417
C -2.7629738101 1.9516274433 -0.4361879997
H -3.1895692611 2.6096940181 0.3162451418
C -3.5281954647 1.4836253109 -1.4973006729
C -2.9365695168 0.6077687433 -2.4042582632
H -3.491086834 0.2200528414 -3.2537097814
C -1.5967938311 0.2472407741 -2.2229533551
N -0.8200404259 0.7096227174 -1.208017784
N 1.1562581003 0.092328061 -3.2361944638
C 0.1517163396 -0.5897006377 -3.8129278939
268
C 0.2340282568 -1.2081918302 -5.064085535
H -0.6279049645 -1.7409083828 -5.4455235434
C 1.4300948187 -1.1192762489 -5.8004823041
C 2.4723965614 -0.3647585461 -5.2189878762
H 3.4433980529 -0.2809632811 -5.68982653
C 2.2792413949 0.2083552538 -3.9625772869
H 5.8624294508 0.1621298603 1.0457541191
C 5.3597341774 0.3502888939 0.1016103362
C 3.9815391401 0.1431237932 -0.0058051888
N 3.2645348664 0.3873328068 -1.1357707253
C 3.9778719917 0.7994254852 -2.211991414
C 5.3574237903 1.0479135679 -2.1839983556
H 5.8653664845 1.3798046426 -3.0855810133
C 6.061273594 0.8199423913 -1.0073092927
N -1.0562538952 -0.67053986 -3.1288884788
H -1.7691554159 -1.1600747303 -3.6526929196
N 3.3230250338 0.9924593029 -3.4349592963
H 3.9844584253 1.2450619813 -4.1577396441
N 3.3225527055 -0.3798290877 1.1132080957
N -0.7192769263 1.9834016643 0.797304223
H -1.3127929603 2.547283982 1.3918350979
Co 1.2027247053 0.2183952825 -1.1232489249
H 3.9618195785 -0.8003376027 1.774285563
N 0.6894590126 0.2854563051 5.0981474031
N 1.5722507888 -1.7325027292 -7.0261269001
C 1.5552290052 -0.6156827963 5.8468794962
H 2.5963447789 -0.2703502404 5.8251309523
H 1.5222556406 -1.6440392458 5.4566495881
H 1.2345860633 -0.6327749385 6.8900465001
C -0.573012462 0.6956970786 5.6957756229
H -0.7573958982 1.763245063 5.5258835452
H -0.5244502184 0.5379503577 6.7748685537
H -1.4287122321 0.126948121 5.299924052
C 2.8739546621 -1.7484046585 -7.678449776
C 0.5718865594 -2.6996120575 -7.4596110421
H 3.6230358614 -2.3221433017 -7.1103296141
H 3.2510438114 -0.7289969293 -7.8186021548
H 2.7697273564 -2.1989014157 -8.6672833586
H 0.4640897072 -3.5314131147 -6.7475338208
H 0.8686413893 -3.1088788315 -8.4270330958
H -0.4076266955 -2.2227681224 -7.5875924842
C 1.0328544417 -1.822701924 -0.7945347093
O 0.2361357296 -2.0758953349 0.1190771468
O 1.7523870062 -2.4678465512 -1.5691720573
H -4.5645496258 1.787495385 -1.6124431534
H 7.1318285444 0.9953411732 -0.9559585035
269
Listing 13. Coordinates of 3
(I)
-CO2
H 2.8080683743 -0.2115656628 3.8059848157
C 1.9937463333 0.1602974961 3.1962037889
C 0.9122376919 0.8617457694 3.7623080257
C -0.0605400342 1.3382088819 2.8608060632
H -0.9588975412 1.8346355072 3.206139046
C 0.1005820072 1.1169238582 1.4870364053
N 1.1309125197 0.4390857974 0.9334763881
C 2.0550298535 -0.0195746488 1.8066542384
C -1.554771074 0.9620178089 -0.3810419555
C -2.9366706043 1.1145272803 -0.4627752895
H -3.4542940963 1.7406293079 0.2596572908
C -3.6458952867 0.4182377006 -1.4515990986
C -2.9138140138 -0.3970789488 -2.3258252457
H -3.4074576224 -0.9418767048 -3.1268177309
C -1.5297686623 -0.4703915851 -2.191216885
N -0.8181561003 0.1897625801 -1.2312687602
N 1.3446777679 -0.346553285 -3.1247996897
C 0.3294692015 -0.9270037622 -3.8025634726
C 0.3466650543 -1.2078684512 -5.1753140485
H -0.5442281396 -1.6177989971 -5.6345524856
C 1.4938776482 -0.9043131941 -5.9343134046
C 2.5571055686 -0.2960468154 -5.2389706105
H 3.4892674457 -0.0534111891 -5.7336726997
C 2.4332119361 -0.0409973071 -3.8664329935
H 5.7481534373 -0.7954762829 1.2753493088
C 5.3139303819 -0.512811767 0.319470872
C 3.930245083 -0.4217906251 0.1878788846
N 3.2938707769 -0.061890382 -0.965760009
C 4.1092800116 0.2244499358 -2.0220193655
C 5.5004389987 0.1861276586 -1.9682589286
H 6.0818724889 0.4170162118 -2.8573470865
C 6.1296772186 -0.1954995428 -0.7748654614
N -0.8207436515 -1.2867113093 -3.090633462
H -1.4604202819 -1.8095842824 -3.6749238233
N 3.5077057783 0.5965993588 -3.2364092829
H 4.2079680702 0.8811599894 -3.9090756605
N 3.1414101055 -0.7420888803 1.3056064563
N -0.8713922492 1.65452894 0.6338453445
H -1.5051198432 2.25927141 1.1404854771
Co 1.2388063102 0.0601210069 -1.0975306116
H 3.7140174862 -1.107415289 2.0554553821
N 0.8151885651 1.0760815357 5.1239963086
N 1.5760590357 -1.1914193154 -7.2831129762
C 1.6880449871 0.3390538779 6.0257783541
H 2.7414240678 0.5795475974 5.838903957
270
H 1.5605733317 -0.7513983194 5.9342323985
H 1.462719116 0.6270781224 7.0545178396
C -0.3934482626 1.6720466523 5.6720201854
H -0.5924463916 2.6421802481 5.2032056194
H -0.2527085137 1.8454463262 6.7410452441
H -1.2815310753 1.0329244243 5.5377841494
C 2.6788924159 -0.6501219625 -8.0632783634
C 0.3971921187 -1.6654259519 -7.9908802301
H 3.6422526669 -1.0100411424 -7.6825733785
H 2.6957044242 0.4515499811 -8.0605407677
H 2.5848835547 -0.990142501 -9.0964847786
H 0.0032899601 -2.576080415 -7.5247880599
H 0.6739595769 -1.9145323438 -9.0175374572
H -0.4098888004 -0.9152807831 -8.0220484056
H -4.7242234564 0.5061520943 -1.5360783779
H 7.21121433 -0.245825712 -0.7015809871
Listing 14. Coordinates of 3
(0)
H 2.7429221136 -0.3861623389 3.8002757221
C 1.9426312039 0.018077882 3.1935949502
C 0.878318069 0.7485527696 3.7770863291
C -0.0828588011 1.2766405557 2.8799629069
H -0.9505199298 1.8144399725 3.2404431236
C 0.0601743775 1.0572581027 1.5157320897
N 1.072021267 0.3582672063 0.959178705
C 1.9904990161 -0.1389564975 1.8135207968
C -1.5688994425 0.9335611755 -0.3732524159
C -2.9544658122 1.0890286058 -0.4549481094
H -3.4832259 1.69242331 0.2754272649
C -3.6433596535 0.4216227372 -1.4642791673
C -5.1380950316 0.5925653296 -1.5879391377
C -2.9313476786 -0.370749543 -2.3560254183
H -3.4337285895 -0.8909968689 -3.1636644169
C -1.5423114648 -0.4595411153 -2.2114405702
N -0.8450729165 0.1768348178 -1.2380171326
N 1.3026226547 -0.3127336059 -3.1593800627
C 0.2996378577 -0.9067440907 -3.8398735508
C 0.3351525712 -1.1899878442 -5.2000289047
H -0.5338755721 -1.6312056029 -5.6710278225
C 1.4817188346 -0.8443905375 -5.9559996141
C 2.5310355173 -0.2109508898 -5.2453741869
H 3.4579003285 0.054728283 -5.7372030072
C 2.3930659939 0.0216099012 -3.8822513563
H 5.6690325702 -0.8346940931 1.266820581
C 5.2290359508 -0.5312237629 0.322531916
C 3.8427478464 -0.4761535859 0.1743225772
N 3.2240362629 -0.0835963796 -0.9701894631
271
C 4.03018222 0.2585417821 -2.0049987106
C 5.4288578101 0.2465749624 -1.9363820627
H 6.0242544448 0.5166798461 -2.8010535998
C 6.0320845673 -0.1563232595 -0.752376878
C 7.5335739345 -0.1801715371 -0.6005995796
N -0.8492573641 -1.270721588 -3.1195688196
H -1.4873297473 -1.8122655352 -3.6893058953
N 3.4475555825 0.6629792953 -3.2116490771
H 4.1427955917 1.0130233693 -3.8591171837
N 3.0537346288 -0.8736406243 1.2636459323
N -0.8972180733 1.613119034 0.6508572464
H -1.5159623206 2.2481932239 1.1396642928
Co 1.1897087044 0.0319943743 -1.1010442789
H 3.6156930296 -1.3089881362 1.9848803069
F 8.1700404429 0.0848126186 -1.7613194652
F 7.9639312994 -1.3878090532 -0.1636502808
F 7.9466127888 0.736732196 0.3083255247
F -5.6793920724 -0.2805127188 -2.4644116803
F -5.4544481174 1.8406866761 -2.0118710755
F -5.7561942955 0.4138809169 -0.3963982679
N 0.7845978408 0.9332807912 5.1209277387
N 1.5712117667 -1.1052509071 -7.2875377116
C 1.7613925002 0.3204386551 6.0188623988
H 2.7714991915 0.7103021169 5.8388600638
H 1.7769648405 -0.7710053498 5.9062560667
H 1.4906731163 0.5497864857 7.0493394467
C -0.3159551693 1.7140877404 5.6822757483
H -0.3411397058 2.7249437204 5.257454603
H -0.1746820218 1.806355329 6.7591059141
H -1.2857962864 1.2302945082 5.5054520465
C 2.7364102478 -0.6600669081 -8.0495063659
C 0.4916136741 -1.8087803189 -7.9776176371
H 3.6521003548 -1.1656759666 -7.7164270666
H 2.877556834 0.4243732339 -7.9625127476
H 2.5835789141 -0.8955033949 -9.1026640636
H 0.2549658488 -2.7541020743 -7.4754178613
H 0.8110882101 -2.0415835833 -8.9935392024
H -0.4199648539 -1.1986838139 -8.0361704445
Listing 15. Coordinates of 4
(II)
H 2.6553534739 -0.5478622256 3.7632698126
C 1.9049524038 -0.0980795942 3.1263682371
C 0.9363310039 0.8018531454 3.6556033907
C 0.0624971293 1.3947074852 2.7028161581
H -0.7235487986 2.0709466023 3.0124096352
C 0.1661596262 1.0622597656 1.3655174192
N 1.0793764153 0.1905421756 0.8661275556
272
C 1.9386396993 -0.3482498478 1.7702037868
C -1.4475832977 0.9110251689 -0.4849973708
C -2.8184748153 1.1376258268 -0.6286363792
H -3.3166546642 1.8803171911 -0.0142018679
C -3.5326236456 0.357415959 -1.5310748212
C -5.0305266 0.5765644839 -1.678297014
C -2.868938804 -0.5990234922 -2.2901191877
H -3.3956064222 -1.1981067874 -3.0242878422
C -1.4887023357 -0.7287388065 -2.127618153
N -0.7810514442 -0.0086868308 -1.2244052947
N 1.2750738604 -0.4600021064 -2.9861044306
C 0.32406228 -1.1298782456 -3.6885027861
C 0.3514686713 -1.3237386537 -5.0539610214
H -0.471400212 -1.8424604239 -5.5280535861
C 1.4177359487 -0.7784292763 -5.8242588847
C 2.3941988071 -0.0478541951 -5.0921826243
H 3.2525256224 0.3850642912 -5.5889083513
C 2.2868556562 0.0704753864 -3.719320442
H 5.598813009 -1.1244979772 1.2571037034
C 5.1433650958 -0.7329672704 0.3537561968
C 3.7592600505 -0.718813853 0.2083432399
N 3.1390278734 -0.2393275806 -0.9006457416
C 3.9096269785 0.2887033102 -1.8789643912
C 5.3054524823 0.3587470414 -1.7826793542
H 5.8901781626 0.7865425404 -2.5889625129
C 5.9197331092 -0.1766864216 -0.6612336426
C 7.4336314035 -0.1708641104 -0.5157721777
N -0.7662641422 -1.6157518575 -2.9334032534
H -1.3684812537 -2.2288439522 -3.4723972268
N 3.2806104725 0.7769086897 -3.0190494577
H 3.916719507 1.2670054017 -3.6375528988
N 2.9349333226 -1.1940852636 1.2358625973
N -0.7231724999 1.6483092473 0.4474454251
H -1.2690838712 2.3955745097 0.8608518535
Co 1.1656738307 -0.3157863625 -1.0301838679
H 3.4561680648 -1.6833625181 1.9556951523
F 8.0293988728 0.471925891 -1.5348405255
F 7.9022588707 -1.4343680904 -0.4818193722
F 7.7912934345 0.4343066847 0.6352542642
F -5.5697534864 -0.2713106775 -2.5716676633
F -5.2811192548 1.8366457773 -2.0868112091
F -5.6500706816 0.3946019467 -0.4948624922
N 0.859917975 1.0786591693 4.9719597949
N 1.491942068 -0.9355092976 -7.160446818
C 1.7113808155 0.3667507805 5.9330505029
H 2.7678513555 0.6313987238 5.8035115195
273
H 1.5918835525 -0.7175800359 5.831638038
H 1.4131576361 0.6439078438 6.9432529093
C -0.0932997357 2.0761792465 5.4728803334
H 0.0187167957 3.02541031 4.9381254252
H 0.110458179 2.2617213221 6.5266780256
H -1.1279295473 1.7234994689 5.3789046117
C 2.5638914704 -0.288658624 -7.9271247244
C 0.4934220189 -1.7418299178 -7.8732588742
H 3.5469859969 -0.685727703 -7.6474322788
H 2.5532510308 0.7970981363 -7.7780652485
H 2.4091841317 -0.4838075023 -8.9873089755
H 0.4446810125 -2.7563703655 -7.4624950536
H 0.7826573794 -1.8178576026 -8.9204107724
H -0.5005322169 -1.2802924117 -7.825731497
C 1.0234609693 -2.3596393291 -0.6829719265
O 0.9378702038 -3.474454312 -0.4913875747
Listing 16. Coordinates of 4
(II)
-CO
H 2.6109013822 -0.4551731506 3.7596818705
C 1.8649686506 0.0036700706 3.1238063005
C 0.8586411753 0.8406107884 3.6599045898
C -0.0008279915 1.4543690699 2.7150650128
H -0.8144423723 2.094963602 3.0295327849
C 0.1531630685 1.1849871551 1.3645439178
N 1.0915742957 0.3557556998 0.8528581193
C 1.9445006516 -0.1886767305 1.7518350995
C -1.4729815227 1.0398812121 -0.453432294
C -2.8610603499 1.1621982632 -0.478110928
H -3.3652671547 1.8448163399 0.1975566299
C -3.5806354107 0.3506935553 -1.3545668893
C -5.0887838029 0.4627536557 -1.3946086664
C -2.9022592896 -0.5316429621 -2.17997724
H -3.4305595478 -1.1605717363 -2.8873662902
C -1.5017572894 -0.5622239227 -2.1152525251
N -0.7875481603 0.1994551617 -1.2590719706
N 1.2763494205 -0.3096299229 -2.9998911802
C 0.3275035568 -0.9838615748 -3.6909270609
C 0.3874498612 -1.2491237601 -5.0510355255
H -0.4414955727 -1.7632599498 -5.5196257861
C 1.4891363472 -0.7885231524 -5.8096049355
C 2.4568006183 -0.0379929379 -5.0972894229
H 3.3409273833 0.344598158 -5.590248709
C 2.3098381516 0.1616986718 -3.7335828853
H 5.6206281645 -1.1291604767 1.155120929
C 5.1701064172 -0.7068875538 0.2632497471
C 3.7816593767 -0.5660515821 0.1725846147
N 3.1656222744 -0.0335276924 -0.9076423878
274
C 3.9445716277 0.3838861844 -1.9253796338
C 5.3403667635 0.3161222236 -1.9027808518
H 5.9227290616 0.6611805115 -2.7489167593
C 5.9523163044 -0.2464208547 -0.7885285286
C 7.4581324362 -0.3744359069 -0.7049174031
N -0.8071905073 -1.3948501747 -2.9813425318
H -1.4082728565 -2.012112846 -3.512563489
N 3.298379361 0.9011453712 -3.053196168
H 3.9510537458 1.3306897972 -3.6984724508
N 2.9914863633 -0.9641188125 1.2443454606
N -0.7231933278 1.8038585796 0.4496966573
H -1.2885398371 2.5140081081 0.9003030239
Co 1.1740420886 -0.1236484825 -1.04797593
H 3.5108161874 -1.4551870019 1.961178885
F 8.0761473496 0.2281744737 -1.7420729311
F 7.8385892045 -1.6718640542 -0.6992137618
F 7.9300114304 0.18423424 0.4346302026
F -5.6452866161 -0.4336359698 -2.2345517596
F -5.4693947101 1.6967844106 -1.8016956488
F -5.6247760025 0.2661486454 -0.167853713
N 0.7321399995 1.0521959741 4.9964789004
N 1.6088142004 -1.0388071113 -7.1398076002
C 1.5698529013 0.3121494048 5.9388821622
H 2.6304664297 0.5685793643 5.8208033987
H 1.4491897668 -0.7710055316 5.8113950296
H 1.2730684848 0.5679398878 6.9558925224
C -0.2935301133 1.9586315803 5.5087215131
H -0.2133239469 2.9473084595 5.0419770875
H -0.1516333359 2.0857091238 6.5820169454
H -1.3054822547 1.5654998288 5.3407059666
C 2.7120449177 -0.4575881268 -7.902888498
C 0.6089095644 -1.8493177871 -7.8323974101
H 3.6816533981 -0.8434307847 -7.5626118413
H 2.7174144327 0.6370558299 -7.8256208035
H 2.593934071 -0.7189977863 -8.9543476526
H 0.4539829354 -2.8038098424 -7.3169360899
H 0.9644487569 -2.0688938943 -8.8392645519
H -0.3540350072 -1.3265337553 -7.9142575346
C 1.0788437114 -2.1357005893 -0.7403366277
O 0.1057105949 -2.5589327966 0.1600665869
O 1.7832534843 -2.9873941976 -1.2633296267
H 0.1702466109 -3.5378299905 0.2112305358
Listing 17. Coordinates of 4
(II)
-CO2H
H 2.7804073378 -0.5071323928 3.8050542343
C 1.9907736214 -0.0685053974 3.2083089621
C 0.9091403367 0.6136794834 3.8042064004
275
C -0.0280703923 1.1944130338 2.9229163855
H -0.9133023832 1.6973169858 3.2909954199
C 0.1482981181 1.0521614918 1.5459140089
N 1.1621872156 0.3833308393 0.9751692884
C 2.0697942374 -0.1483707773 1.8176326237
C -1.4958898936 1.0847159578 -0.3522051289
C -2.8596944533 1.3752702712 -0.4496210212
H -3.338546004 2.0039334366 0.2934376829
C -3.5998390292 0.7965534891 -1.4803431435
C -5.055016203 1.1132063857 -1.6480997424
C -2.9444554945 -0.0402120578 -2.3862418756
H -3.4791719225 -0.498937278 -3.2105801467
C -1.5764776272 -0.2618566366 -2.2257874723
N -0.8327360159 0.2862407375 -1.2277437761
N 1.2397140135 -0.2923361422 -3.1797549086
C 0.2268293883 -0.8804201505 -3.8418538288
C 0.2721187659 -1.2557857651 -5.1839205216
H -0.6046613951 -1.6973229858 -5.6401163522
C 1.4472050764 -1.0130957742 -5.9282187299
C 2.4986783514 -0.36204668 -5.2507621982
H 3.4467386365 -0.1691491125 -5.7363896785
C 2.347548859 -0.0295363625 -3.9011084551
H 5.7335468127 -0.4429763577 1.2658021221
C 5.2725052212 -0.212678761 0.3108118919
C 3.9019525637 -0.3349422804 0.1544355103
N 3.2273399552 -0.0411779478 -1.001648757
C 4.0068128038 0.3646844669 -2.0457802195
C 5.3886751359 0.5228615307 -1.9737196257
H 5.9466005178 0.8334243123 -2.8507261507
C 6.0498268837 0.2271297713 -0.7767299042
C 7.5182821607 0.4183427085 -0.6220651788
N -0.955870613 -1.1228362312 -3.1365675087
H -1.631745906 -1.6310016631 -3.6917842187
N 3.3994945536 0.648108033 -3.2798188102
H 4.0876820098 0.95606876 -3.954389671
N 3.1526231672 -0.815987401 1.2461534687
N -0.7955755068 1.6703424391 0.7072064054
H -1.395074963 2.2935909258 1.2327758462
Co 1.1990540105 -0.208492138 -1.0714686503
H 3.7440337036 -1.2523033964 1.9418686386
F 8.1543391122 0.581546344 -1.8105308761
F 8.1178795625 -0.6293089169 0.0109736056
F 7.8286194707 1.5218563487 0.1309483123
F -5.7283435173 0.1166857746 -2.2749911787
F -5.2531020551 2.2389277559 -2.3956068261
F -5.6760441597 1.3344922778 -0.4613675362
276
N 0.7814951548 0.7156963555 5.1673437135
N 1.5542043678 -1.3868117534 -7.2421761258
C 1.6521126626 -0.0663879737 6.0363842909
H 2.7049413103 0.2027985148 5.8886366665
H 1.5407108636 -1.1472677941 5.8661062247
H 1.3997571974 0.1456220741 7.0765352147
C -0.3960063676 1.3516654367 5.7421829092
H -0.5146450564 2.3718998804 5.3588497273
H -0.2722337251 1.4179464629 6.824429614
H -1.319585215 0.7903879402 5.5331446278
C 2.7612517469 -1.0755462788 -7.9952669541
C 0.4808261659 -2.1387173485 -7.8788778963
H 3.641060512 -1.5967675348 -7.5919202516
H 2.9650844601 0.0034058115 -7.9928752311
H 2.6263368632 -1.3885711154 -9.0315935989
H 0.2431726416 -3.0502318992 -7.315008522
H 0.7977182266 -2.4357070955 -8.8796800991
H -0.4364094925 -1.5404773406 -7.9765184062
C 0.9533221245 -2.2805702761 -0.638510759
O 0.0620926399 -2.4437056629 0.1842896607
O 1.7444188513 -2.8959013574 -1.3408635202
Listing 18. Coordinates of 4
(I)
-CO2
277
Appendix 5.2: NMR Spectra
278
Spectrum 5.1. 500MHz
1
H NMR of B in CDCl3
Spectrum 5.2. 126MHz
13
C{
1
H} NMR of B in CDCl3
279
Spectrum 5.3. 500MHz
19
F NMR of B in CDCl3
Spectrum 5.4. 500MHz
1
H NMR of C in CDCl3
280
Spectrum 5.5. 126MHz
13
C{
1
H} NMR of C in CDCl3
Spectrum 5.6. 500MHz
19
F NMR of C in CDCl3
281
Spectrum 5.7. 500MHz
1
H NMR of D in CDCl3
Spectrum 5.8. 126MHz
13
C{
1
H} NMR of D in CDCl3
282
Spectrum 5.9. 500MHz
19
F NMR of D in CDCl3
Spectrum 5.10. 500MHz
1
H NMR of
CF3
L in Acetone-d6
283
Spectrum 5.11. 126MHz
13
C{
1
H} NMR of
CF3
L in Acetone-d6
Spectrum 5.12. 500MHz
1
H NMR of
CF3
L in Acetone-d6
284
Spectrum 5.13. 500MHz
1
H NMR of F in CDCl3
Spectrum 5.14. 126MHz
13
C{
1
H} NMR of F in CDCl3
285
Spectrum 5.15. 500MHz
1
H NMR of G in CDCl3
Spectrum 5.16. 126MHz
13
C{
1
H} NMR of G in CDCl3
286
Spectrum 5.17. 500MHz
1
H NMR of
NMe2
L in CD3OD
Spectrum 5.18. 126MHz
13
C{
1
H} NMR of
NMe2
L in CD3OD
287
Spectrum 5.19. 500MHz
1
H NMR of I in CDCl3
Spectrum 5.20. 126MHz
13
C{
1
H} NMR of I in CDCl3
288
Spectrum 5.21. 500MHz
19
F NMR of I in CDCl3
Spectrum 5.22. 500MHz
1
H NMR of J in CDCl3. The impurities in the spectrum correspond to
cycles bearing isomerized allyl groups.
289
Spectrum 5.23. 126MHz
13
C{
1
H} NMR of J in CDCl3
Spectrum 5.24. 500MHz
19
F NMR of J in CDCl3
290
Spectrum 5.25. 500MHz
1
H NMR of
Mix
L in CD3OD
Spectrum 5.26. 500MHz
19
F NMR of
Mix
L in CD3OD
291
Spectrum 5.27. 126MHz
13
C{
1
H} NMR of
Mix
L in CD3OD
Abstract (if available)
Abstract
Carbon dioxide (CO₂), a fossil-fuel combustion product, is a major pollutant responsible for climate change. In recent years, there has been a great push to apply renewable energy to capture CO₂ and reduce it to provide carbon-neutral fuels and other useful products. One promising strategy for this approach is using organometallic catalysts with enzyme like structural features. This work will describe the design strategy behind a novel CO₂ reduction catalyst bearing hydrogen bond donors in the secondary sphere that can convert CO₂ to CO selectively at high turnovers. The reactivity of this complex will be rationalized through a series of synthetic, electrochemical, and theoretical studies, revealing the importance of the pendant amines for catalysis. Additionally, the approaches taken to enhance the catalyst performance through the alteration of the electrostatic and electronic environments around the metal center will also be presented and analyzed.
Linked assets
University of Southern California Dissertations and Theses
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Asset Metadata
Creator
Chapovetsky, Alon
(author)
Core Title
Design, synthesis, and investigation of a bio inspired CO₂ reduction catalyst
School
College of Letters, Arts and Sciences
Degree
Doctor of Philosophy
Degree Program
Chemistry
Publication Date
02/14/2019
Defense Date
10/23/2019
Publisher
University of Southern California
(original),
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(digital)
Tag
bioinspired,carbon dioxide,catalyst,chemistry,electrochemistry,enzyme,inorganic,OAI-PMH Harvest,organic
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application/pdf
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Language
English
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Electronically uploaded by the author
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Advisor
Marinescu, Smaranda C. (
committee chair
), Smith, Adam L. (
committee member
), Thompson, Mark E. (
committee member
)
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Chapov@gmail.com,Chapovet@usc.edu
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https://doi.org/10.25549/usctheses-c89-121480
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UC11675931
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Tags
bioinspired
carbon dioxide
catalyst
chemistry
electrochemistry
enzyme
inorganic
organic