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2-nitrophenyl-α-trifluoromethyl carbinols as smart synthons for novel fluoroorganics

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2-nitrophenyl-α-trifluoromethyl carbinols as smart synthons for novel fluoroorganics

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Content 1

2-Nitrophenyl-α-Trifluoromethyl Carbinols as
Smart Synthons for Novel Fluoroorganics

by

Kavita Belligund

A Dissertation Presented to the
FACULTY OF THE USC GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirement for the Degree
DOCTOR OF PHILOSOPHY
(CHEMISTRY)

May 2019

Copyright 2019 Kavita Belligund

2

Dedication
I dedicate this thesis to my parents.

I dedicate my thesis to my parents. I would love to thank my mother for always encouraging her
10-year-old girl’s crazy dream of finding a cure for diabetes. Although my career took a very
different turn, I do not think I would have chosen to study the physical sciences without her
encouragement. I also thank my dad for being such a good tutor, getting me books about science
outside the regular school course work, going through the agony of teaching a high school student
thermodynamics for the first time. I would have never had a strong fundamental knowledge to
build on if it weren’t for him. I must add he would often say “Kavita, I don’t remember studying
so hard to understand chemistry, even during my days in IIT-Bombay”. I am sincerely grateful to
them for always having faith in me
.

3

Acknowledgement

Firstly, I would like to express my sincere gratitude to my advisor Prof. G. K. Surya Prakash for
the continuous support of my Ph.D. study and related research, for his patience, motivation, and
immense knowledge. His guidance helped me in all the time of research and writing of this thesis.
I could not have imagined having a better advisor and mentor for my Ph.D. study.
My sincere thanks also goes to Prof. Jahan Dawlaty for giving me access to his laboratory and
research facilities. I would also like to thank Jonathan Ryan Hunt for all his experimental work
and analysis on the laser flash photolysis done in this project. Without their precious support it
would not be possible to conduct this research.
I would also like to Dr. Thomas Mathew for all the insight and guidance he has provided on the
project described in this thesis.
I am especially grateful to two of my lab mates Archith Nirmalchandar , Alexandra Aloia and
Sahar Roshandel who have been instrumental in providing me very constructive feedback on my
thesis, publication, and other aspects of my career. Additionally, I would like to thank Archith for
all the help he has provided with my experiments. I would also like to recognize Dr. Zhe Zhang
who mentored me when I was a first-year graduate student.
I would like to thank my committee members; Prof. Ralf Haiges for his help on single crystal X-
ray structures and Prof. Katherine Shing for making the time to be at my screening, qualifier and
defense. Also, I would like to thank my past committee Prof. Barry Thompson, Prof. Golam Rasul
and Prof. Theo Hogensch.
4

Thank you all the current members and some of the past members of the Prakash Group for your
friendship and support: Dr. Laxman Gurung, Dr. Sankarganesh Krishnamoorthy, Dr. Robert
Anizfeld, Huong Dang, Sayan Kar, Dr. Alain Geoppert, Dr. Patrice Batamack, Dr. Marc Iuliucci,
Vinayak Krishnamurthi, Colby Barett, Xanath, Amanda Baxter, Vicente Galvin, Dr. Dean Glass ,
Raktim Sen and Jessie May.
Last but not least I would also like to thank all my friends who have made my stay in Los Angeles
feel like it was a second home to me.

5

Table of Contents
Chapter 1: Introduction ........................................................................................ 11
1.1. General Principles of organic photochemical reactions ............................................... 11
1.2. Synthetic Utility of Photochemical reactions ................................................................. 12
1.3 Introduction - Photochemistry of the nitro functionality .............................................. 13
1.4. Photochemistry of 2-nitrobenzaldehyde, 2-nitrotoluenes ............................................ 14
1.5. Photoexcitation of 2-nitrobenzyl systems ....................................................................... 17
1.6. 2-Nitrodiphenylmethane derivatives as photolabile protecting groups ..................... 18
1.7. Photolysis of 2,2'-dinitrodiphenylmethanes: synthesis of 3-(2'-nitrophenyl)-2,1-
benzisoxazoles, acridine and dibenzo[c,f]-[1,2]diazepine systems ..................................... 21
1.8. Photolysis of 2-nitrodiphenylmethanes ......................................................................... 26
1.9. Photolysis of 1,2-bis(2-nitrophenyl)ethane .................................................................... 27
1.10. Photolysis of 2-nitrostilbenes ........................................................................................ 28
1.11. Conclusion ....................................................................................................................... 30
1.12. References ........................................................................................................................ 30

Chapter 2: 2-nitrophenyl-α-trifluoromethyl carbinols as smart synthons for
novel fluoroorganics ............................................................................................. 42
2.1 Introduction ........................................................................................................................ 42
Result and discussion ............................................................................................................... 45
2.2 Steady-state photolysis of 2-nitrophenyl-α-trifluoro-methyl carbinols in 2-propanol:
synthesis of 2,2'-bis(trifluoroacetyl)azoxyarenes ................................................................. 45
2.3 Synthesis of trifluoromethylated benzisoxazole .............................................................. 50
2.4 Transient absorption spectroscopy ................................................................................ 54
2.5 Steady-state photolysis in DMSO and analysis of the photolysate ............................... 56
2.6 Plausible mechanism ........................................................................................................ 59
2.7 Conclusion .......................................................................................................................... 61
2.8 Experimental section ......................................................................................................... 62
2.9 References ........................................................................................................................... 79
2.10 Appendix ........................................................................................................................... 88

6

List of Schemes
Chapter-1
Scheme 1: Photochemical reactions used in organic synthesis

13
Scheme 2. Photochemistry of nitroarenes in protic solvents

14
Scheme 3. Photo-redox reaction of o-nitrobenzaldehyde

15
Scheme 4. Light induced tautomerization of o-nitrotoluenes and effect of
substituent

17
Scheme 5. Hydrogen transfer on photoexcitation of o-nitrobenzyl derivatives 16
and the possible intermediates

18
Scheme 6. Mechanism of photo-deprotection of carboxylic acid from o-
nitrobenzyl esters

19
Scheme 7. Photochemical orthogonal deprotection of the bifunctional substrate 26
bearing o-nitrobenzyl chromophore

21
Scheme 8. 2,2'-Dinitrodiphenylmethanes 41, photosynthon for 2,1-benzisoxazole
38, dibenzo[c,f]-[1,2]diazepin-11-one 39, 40, 43 and acridone systems 42

23
Scheme 9. Photolysis of 2,2'-dinitrodiphenylmethanes 41 in 2-propanol

24
Scheme 10. Preparation of dibenzo-[c f]-[1,2]diazepin-11-ones 43 and the N-
oxides 39

24
Scheme 11. Photolysis of 2,2'-dinitrodiphenylmethanes 41 in EtOH-H2SO4

25
Scheme 12. Phototransformation of 3-(2'-nitropheny1)-2,1-benzisoxazole 38a in
EtOH-H2SO4

26
Scheme 13. Phototransformation of 2-nitrodiarylmethanes 46 27
7

Scheme 14. Phototransformation of 1,2-bis(2-nitrophenyl)ethane 48

28
Scheme 15. Synthesis of isatogens 54 from 2-nitrostilbenes 53 through nitro-ene
photocycloaddition

29
Scheme 16. Intramolecular photocyclization of 4-(2'-nitrobenzylidene)-4H-pyrans
58

30

Chapter 2
Scheme 1. Intramolecular photoredox processes in o-nitro-benzylic systems

42
Scheme 2. Photochemical transformation of 2,2'-dinitro-diphenylmethanes to N-
heterocycles

44
Scheme 3. Photolysis of 2-nitrophenyl-α-trifluoromethyl carbinol: direct access to
2,2'-bis(trifluoroacetyl)azoxy-benzenes

46
Scheme 4. 2-Nitrophenyl-α-trifluoromethyl carbinol, an efficient photosynthon for
solvent-controlled synthesis of 2,2'-bis(trifluoroacetyl)azoxyarenes, 2-
trifluoroacetyl nitrosoarenes and trifluoromethylated isoxazolines

50
8

Scheme 5. Formation of 2-trifluorocetyl nitrosoarenes 7a-e and the hydrates 8a-e
from photolysis of 4a-e in MeCN; X- ray crystal structure of 8d' (the dimer of the
hydrate 8d)
53

Scheme 6. Synthesis of isoxazoline 6e by the photolysis of 2,2,2-trifluoro-1-(5-
methoxy-2-nitrophenyl)-ethanol 4e in DMSO

58
Scheme 7. Plausible mechanism leading to photoproducts observed during the
irradiation of 4a-i in various solvents

60

List of tables
Chapter 2
Table 1. Synthesis of 2,2-bis(trifluoroacetyl)azoxyarenes by the potolysis of 2-
nitrophenyl-α-trifluoromethyl carbinols in 2-propanol

49
Table 2. Synthesis of trifluoromethylated benzisoxazolesby the photolysis of 2-
nitrophenyl-α-trifluoromethyl carbinols in DMSO

52
Table 3. 2-Trifluorocetyl nitrosoarenes 7a-e and their hydrates 8a-e from the
irradiation of 4a-e in MeCN

54

List of Figures
Chapter 1
Figure 1: Common decay pathways for an organic molecule that has been excited
by a photon

11
9

Figure 2. Few examples of biologically active diazepines, benzisoxazoles, and
acridine derivatives

22

Chapter 2
Figure 1. A few widely used fluorine-containing drugs

43
Figure 2.
19
F NMR spectrum and X-ray crystal structure of 5a

47
Figure 3. X-ray crystal structures of 5f and 5h

48
Figure 4.
19
F NMR spectrum and X-ray crystal structure of 6e

51
Figure 5. Transient absorption spectra of 2,2,2-trifluoro-1-(2-nitrophenyl)ethanol
4a in 2-propanol, 2-propanol with 1% water and 2-propanol with 10% water

55
Figure 6.
19
F NMR taken at different intervals: (A) Solution of 4e in DMSO-d6
after irradiation of for 2.5 h, showing the formation of intermediate; (B) irradiated
mixture left undisturbed for 24 h showing transition of the intermediate to 8e; (C)
after 72 h, showing almost complete conversion of the intermediate to the product
6e

57
Figure 7.
13
C NMR taken at different intervals: (A) Solution of 4e in DMSO-d6
after irradiation of for 2.5 h, showing the formation of intermediate; (B) irradiated
mixture left undisturbed for 24 h showing transition of the intermediate to 8e; (C)
after 72 h, showing almost complete conversion of the intermediate to the product
6e

58

10

Abstract:
Organic photochemical reactions can be used to synthesize a wide array of compounds. Often these
compounds obtained as a result of photochemical reactions are complex and cannot be synthesized
easily by conventional chemical methods. In this work, we exploit the photochemistry of the o-
nitrobenzylic framework. Nitrocompounds on irradiation result in the formation of nitroso, azo,
azoxy arenes, diazepine oxides, isoxazoles, acridones which have value in the material and
medicinal chemistry. We extend this well-known chemistry to o-nitrobenzylic systems containing
trifluoromethyl moiety. Molecules containing the trifluoromethyl moiety are also highly valued in
medicinal chemistry and are found in many commercially available drugs. In this work, we attempt
to combine both of these frameworks together in the effort to generate new series of fluoroorganic
molecules that could have potential medical and material value.
In the first chapter I briefly introduce basic concepts in photochemistry and explain in detail the
photochemistry of the o-nitrobenzylic /2-nitrobenzylic compounds, the mechanism involved, its
synthetic utility as photosynthons and photolabile protecting groups.
In the second chapter there is a brief introduction into the reasoning involved in choosing to work
with the photosynthon 2-nitrophenyl-α-trifluoromethyl carbinols. We describe the solvent
controlled synthesis using these alcohols as substrate to produce 2,2'-bis(trifluoroacetyl)azoxy-
benzenes, 2-trifluorocetyl nitrosoarenes and trifluoromethylated benzisoxazoles in one step using
UV-B light without any catalyst or reagent. Additionally, we also describe the NMR analysis
which explains the formation of trifluoromethylated benzisoxazoline. We also perform a laser flash
photolysis study of these compounds in isopropanol to gain insights into the intermediates being
generated on the pico-second time scale. This chapter also contains all the supplementary data.
11

Chapter 1: Introduction
1.1. General Principles of organic photochemical reactions
In photochemical reactions the reaction is initiated by light. In organic photoreactions this
absorption of light energy causes an excitation of electrons to the valence orbitals resulting in
excited energy states [1,2]. Based on the electronic configuration formed on excitation there are
almost always two types of excited states formed. The first is the singlet state, wherein the spins
of the electrons are opposite. A second state called a triplet state formed when the excited singlet
state undergoes a process called as inter system crossing (ISC). In the triplet state the electrons
have parallel spins. Direct excitation of the electron to the triplet state is spin forbidden. The third
is a Rydberg state [3], however, it is not discussed as it is beyond the scope of this thesis. Unlike
thermal reactions in photochemical reactions the excited states formed immediately on excitation
undergo a redistribution of the electronic states but retain their nuclear geometry.

Figure 1: Common decay pathways for an organic molecule that has been excited by a photon
Once a molecule has reached an excited state it can lose energy through the process of radiative
decay or non-radiative decay. [2] In case of radiative decay the molecule reaches the ground state
Singlet (S*)
Phosphorescence
Fluorescence
(Chromophore) Ground state (S
0
)
Ground
State
(S
o
)
+
Triplet(T*)
Radiative
decay
ISC
hn
hn’
Non-Radiative
decay
New product(s)
Ground
State (S
0
) + heat
12

by emitting light which is lower in energy than the photon it absorbs. This phenomenon is called
as phosphorescence if the molecule in the excited singlet state relaxes by emitting a photon.
However, if it relaxes to the ground state from the excited triplet state generated through inter-
system crossing by emitting a photon it is called fluorescence. The molecule in the excited state
can also relax to the ground state through non-radiative decay. Two common processes of non-
radiative decay include the emission of phonons or heat. But more relevant to this thesis the
excited state can undergo non- radiative decay resulting in the formation of new products.
1.2. Synthetic Utility of Photochemical reactions
As the excited state is formed by absorption of a photon and is high in energy can therefore give
rise to complex products [4]. This ability to access more complicated molecules makes
photochemistry a viable tool in natural product synthesis. It is often used in steps required to
generate rings of high molecular complexity. Some examples include (Scheme 1) the
photocycloaddition step used to synthesize the bicyclic intermediate for the total synthesis of the
alkaloid mesembrine [5]. Merrilactone A is a natural product isolated from Illicium merrillianum,
which has shown clinical properties as a therapeutic agent for neurodegeneration seen in Alzhimers
disease [6]. Mehta and Singh use [2 + 2] cyclophotoaddition addition of an enone and trans-
dichloroethene to overcome the synthetic challenge of synthesizing a cyclobutane ring with two
angular methyl groups, [7]. Greaney et al [8] use the paterno-buchi type reaction to synthesize the
oxo-cyclobutane ring in one of the steps towards the synthesis of the core present in merrilactone
using 6 steps. In all these examples a functional group such as the carbonyl group or a diene acts
as a chromophore which absorbs radiation to undergo photochemical reactions. Other than these
choromophores, another functionality that is highly exploited in photochemistry is the nitro group,
whose chemistry forms the basis of this thesis.
13

Scheme 1: Photochemical reactions used in organic synthesis
1.3 Introduction -Photochemistry of the nitro group
Nitro group is one of the most efficient chromophore showing versatile synthetic utility in organic
synthesis with significant ability for hydrogen abstraction under photoexcitation. It is well-known
that irradiation of aromatic nitro compounds 1 in protic solvents (solvents with abstractable
hydrogen) leads to various reduction products in varying amounts depending on the solvent and
the wavelength of absorption [9]. A series of steps both photochemical and thermal are involved
in the overall transformation. In many of these systems, the first and the key step is the hydrogen
abstraction by the lowest excited n→π
*
triplet state formed during irradiation [10]. Initial reduction
step leads to the nitroso product, which in turn thermally reduced to the final amino product 2 via
MeO
MeO
N
H
NH
O
OMe
MeO
O
hν
CH
3
CN, rt
N
O
H
Me
OMe
OMe
mesembrine
O
O
O
O
O
O
O
O
O
O
HO
Merrilactone A
Cl
Cl
Cl
Cl
hν
O
O
O
EtO
O
O
EtO
hν
O
Core in Merrilactone
bicyclic intermediate
Winkler et al J. Am. Chem. Soc. 1988, 110, 4831−4832
Mehta, G.; Singh, S.R. Angew. Chem., Int. Ed. 2006, 45. 953−955
Iriondo-Alberdi, J.; Perea-Buceta, J. E.; Greaney, M. F. Org. Lett. 2005, 7, 3969−3971
14

the corresponding hydroxylamine. However, nitrosoarenes being significantly photoactive,
undergo further photoreductive coupling to azoxyarenes 3 and o-hydroxyazoarenes 4 (Scheme 2).

Scheme 2. Photochemistry of nitroarenes in protic solvents

1.4. Photochemistry of 2-nitrobenzaldehyde, 2-nitrotoluenes
Photo-induced intramolecular oxidation-reduction reactions of aromatic nitro compounds
containing a C-H bond ortho to the nitro group has been explored by many research groups over
the years. As early as 1901, Ciamician and Silber reported the photo-redox reaction of o-
nitrobenzaldehyde 5 to o-nitrosobenzoic acid 6 (Scheme 3) [11,12], which sparked further interest
for investigation of o-nitrobenzylic systems on photoexcitation.
15

Scheme 3. Photo-redox reaction of o-nitrobenzaldehyde

In fact, further studies on the hydrogen abstraction property by the photoexcited o-nitro
chromophore from C-H bond in the proximity especially in o-nitrobenzylic systems [13] led to the
design and development of many useful photochromic systems such as photolabile protecting
groups [14-19], photoresists [20-22], systems for controlled release of bioactive compounds [12,
23,24], as well as efficient photosynthons [25] giving access to versatile multifunctional
compounds including heterocycles with significant applications. Photodegradation of polymers is
one of the useful and important systems led by the characteristic photochemistry of o-nitrobenzylic
system [26,27]. Mechanistic studies carried out by George and Scaiano [28], and other groups [29-
34] over the years point to the formation of an o-quinonoid species (aci-nitro ketene 7 in the case
of o-nitrobenzaldehyde) as the primary ground state "product" or intermediate in these reactions,
resulting from intramolecular transfer of the benzylic hydrogen to the nitro group (Scheme 3).
Wirz [35] has revisited the photoreaction mechanism of 2-nitrobenzyl compounds, by studying the
light induced tautomerization of 2-nitrotoluenes 8a in solution by flash photolysis as a benchmark
for comparison with the known 2-nitrobenzyl systems. Susequently, he showed the mechanism of
photorelease of methanol from 2-nitrobenyl methyl ether as well as 1-(2-nitrophenyl)ethyl methyl
ether and ATP release from adenosine-5'-triphosphate-[P
6
-(1-(2-nitrophenyl)-ethyl)] ester ('caged
16

ATP') [36]. Wettermark's study in the 60's showed that irradiation of 2-nitrobenzyl compounds
with at least one H-atom at the benzylic position generates their aci-nitro tautomers in the primary
photochemical reaction (Scheme 3) [37]. With the absence of substituents at the benzylic position,
the colorful aci-nitro compounds (yellow) revert to the starting materials. Substrates such as 2-
nitrotoluene [38], 2,4- and 2,6-dinitrotoluenes [39,40],

2,4,6-trinitrotoluene [41], and 2-(2',4'-
dinitrobenzyl)pyridine [42,43] all show vivid characteristic photochromic behavior. Presence of a
suitable leaving group at the benzylic position initiates the formation of 2-nitrosobenzyl
compounds from the aci-tautomers 9 resulting in efficient deprotection of the leaving group.

The photochromic behavior resulting from the aci-nitro equilibrium exhibited by these substrates
have been studied by Margerum and Miller [44]. Studies have shown that the reaction rates of the
aci-nitro intermediates 9 depend strongly on the nature of the substituents, solvent, and pH [45-
48]. Except in certain cases [49], abstraction of α-hydrogen from the o-alkyl group results in the
formation of o-quionoid aci-nitro form as shown in 8→9 (Scheme 4). Photoreactions of o-
alkylnitrobenzenes with various degrees of steric crowding (various substitution on the benzylic
position) have been reviewed by Döpp [50]. In weakly basic solution, the aci-nitro quinonoid form
9, being strongly acidic with pKa 3.7-1.1 [25, 38], dissociates into its colored anion 10 with a
relatively long life-time of milliseconds (before reverting back to the parent nitro compound)
[38,39,41]. This is the key process behind the observed photochromism. However, in o-
nitroethylbenzenes 8b, abstraction of a β-hydrogen can lead to the direct formation of the cyclic
intermediate 12 from the diradical 11. Intermediate 12 undergoes dehydration to yield the nitrone
13 as the first observable intermediate [51-53], from which the lactam 14 and cyclic hydroxamic
acid 15 are formed as main isolable products (Scheme 4).
17

Scheme 4. Light induced tautomerization of o-nitrotoluenes and effect of susbstituent

1.5. Photoexcitation of 2-nitrobenzyl systems
Generally, as per the suggestion of Gravel et al. and others, the initial event during photoexcitation
of 2-nitrobenzyl systems 16 is the hydrogen abstraction step that occurs either via the formation
of a triplet biradical 17 [14,29,27,38,45, 54] either from an excited n→π* triplet state or a short-
lived singlet biradical 18 upon photoexcitation of the nitro chromophore. Subsequent concerted
[1,5]-sigmatropic shift leads to the quinonoid intermediate 19 [55]. Following the hydrogen
transfer step, cyclic intermediate N-hydroxybenzisoxazolidine 20 is formed from either the
primary intermediate o-quinonoid 19 or triplet biradical 18 (or both), the former by a polar
cyclization mechanism, and the latter by intersystem crossing to the o-quinonoid intermediate 19.
Though not well susbstantiated, another alternative pathway is the radical cyclization of 18 to 20
via the mesomeric form 18' following intersystem crossing. Final redox product nitroso alcohol
18

21 is obtained by the ring-chain tautomerism (Scheme 5). Thus, the formation of the cyclic
hydroxybenzisoxazolidine intermediate 20 is often envisaged as a key event during the formation
of various products following the photoexcitation of 2-nitrobenzylic systems.

Scheme 5. Hydrogen transfer on photoexcitation of o-nitrobenzyl derivatives 16 and the possible
intermediates

As shown in Scheme 3 in the previous section, with the presence of substituents at the benzylic
position, the outcome of the photochemical events taking place changes significantly and can offer
more feasible and direct approach to many valuable organics especially heterocyclic frameworks.
Often, synthesis of such systems requires many difficult synthetic protocols.

1.6. 2-Nitrodiphenylmethane derivatives as photolabile protecting groups
As mentioned, 2-nitrobenzyl derivatives have been widely used as photolabile protecting groups
in organic synthesis. Using light to release a substrate allows for the removal of a protecting group
19

under mild and neutral conditions, which is advantageous compared to the often used methods of
deprotection using acid or base under harsh conditions that might often be incompatible with the
substrates.
The use of 2-nitrophenylmethyl as a photolabile protecting group (PPG) was first reported by
Barltrop et al. who used it to protect carboxylic acids through ester linkage [56]. Upon irradiation,
the 2-nitrophenylmethane esters 22 produced the corresponding 2-nitrosobenzaldehye 23 and
carboxylic acid 24 (Scheme 6). According to the reaction mechanism, the excited nitro group
abstracts hydrogen from the 2-alkyl substituent to form an aci-nitro form which undergoes
rearrangement to give the nitroso derivative with the release of the carboxylic acid. The efficiency
of deprotection generally depends on the α-substitution of the 2-nitrobenzyl group, i.e., the nature
of the R
1
group. For example, with R
1
= H, the yield of the released benzoic acid was only 17%.
The poor yield was attributed to the conversion of the photoproduct 2-nitrosobenzaldehyde to
azobenzene-2,2’-dicarboxylic acid 25, which acted as an efficient light filter. However, with the
use of α-phenyl-substituted nitrobenzyl esters, the resulting photoproducts were 2-
nitrosobenzophenone derivatives (much less reactive than 2-nitrosobenzaldehyde), which helped
higher availability of the incident light for photo-deprotection and production of carboxylic acids,
resulting in the increased yields in the range 75-95%.

Scheme 6. Mechanism of photo-deprotection of carboxylic acid from o-nitrobenzyl esters 22
20

Subsequently, Patchornik et. al. [57] were able to achieve quantitative yields of the released
carboxylic acids with the use of a 2-nitrodiphenylmethyl group (R
1
= Ph) as the protecting group
for the carboxylic acid function.

Since then, the 2-nitrodiphenylmethane derivatives have been
used as photoremovable protecting groups for various other functionalities such as thiols [58],
amines [59], phosphates [60], phenols [61] and alcohols [62].
In recent years, system with multiple photoprotecting groups (PPGs), which can be independently
addressed by different wavelengths of light (orthogonally addressing multiple PPGs) drew our
attention, due to the selective response of each functionality to selective wavelength in a single
system [63]. Bochet reported the design of “orthogonal” protecting groups with o-nitrobenzyl
derivative as one of them and their selective removal from a multi-protected substrate, in which
the irradiation wavelengths serve as the “orthogonal reagents” [64].
Bochet noted that, for an effective polyfunctional orthogonal photochemical
protection/deprotection system, the intrinsic stability of each protecting group at different
wavelengths should differ significantly, the energy transfer between excited chromophore and the
ground state neighbor should be suppressed and the cleavage occurring at high energy should be
very fast to avoid photodegradation of other sensitive groups. For example, he showed that the
mixed diester 26, bearing a dibenzoin ester at one terminus and an o- nitrobenzyl derivative at the
other serve as a good example for such substrates with orthogonal protecting groups (Scheme 7).
Photolysis of 26 at 254 nm for 5 minutes followed by the treatment of trimethylsilyldiazomethane
resulted in the formation of the diester 27 in high yield (92% by
1
H NMR spectroscopy, 70%
isolated by column chromatography). However, the same experiment at 420 nm gave the diester
28 in 70% isolated yield (also by
1
H NMR spectroscopy). This is a clear manifestation of the
photochemical orthogonal deprotection of a bifunctional substrate.
21

Scheme 7. Photochemical orthogonal deprotection of the bifunctional substrate 26 bearing o-
nitrobenzyl chromophore

1.7. Photolysis of 2,2'-dinitrodiphenylmethanes: synthesis of 3-(2'-nitrophenyl)-2,1-
benzisoxazoles, acridine and dibenzo[c,f]-[1,2]diazepine systems

The commonly used diazepine drugs are (1,4)diazepine derivatives such as diazepam 29,
alprazolam 30, flurazepam 31 etc., which are widely used as anxiolytic, anticonvulsant and
hypnotic drugs (Figure 2). (1,2)-Diazepins such as dibenzo(c,f)-(1,2)diazepines can also be
screened for possible therapeutic activities. 2,1-Benzisoxazoles 32-34 are shown to have
significant biological activity [65-69] and are valuable synthons for important N-heterocyclic
pharmacophores, such as acridines [70,71] quinolones [72-75] and quinazolines [76-78].
22

Therefore, the development of new convenient synthetic strategies for 2,1-benzisoxazoles is
ardently pursued.
Also, many promising anticancer drugs are based on acridine alkaloids and their derivatives. As
cytotoxicity studies with some acridine alkaloids showed noticeable anticancer activity, suitable
modification of the natural molecules to meet requirements needed for clinical evaluation has been
carried out [79,80].

Figure 2. Few examples of biologically active diazepines, benzisoxazoles, and acridine derivatives

Utilizing the photochemistry of 2-nitrobenzyl chromophore, synthesis of 2,1-benzisoxazole
derivatives 38, dibenzo(c,f)-(1,2)diazepin-11-one-N-oxides 39, dibenzo(c,f)-(1,2)diazepin-11-
one-N,N-dioxides 40 and acridones 42 could be achieved by a new synthetic protocol using 2,2'-
dinitrodiphenylmethane derivatives 41. 2,2'-Dinitrodiphenylmethanes 41 could be conveniently
prepared from 4,4'-diaminodiphenylmethane in two steps- (i) nitration using KNO3 in excess
23

H2SO4

[81] followed by (ii) deamination [82] via diazotization and treatment with
hypophosphorous acid or halogenation [83] via diazotization/Sandmeyer reaction. Studies by
Joshua et al. [84,85] showed that the photoreactions of 2,2'-dinitrodiphenylmethanes 41 can lead
to the formation of six-membered acridone 42 as well as seven membered dibenzo[c,f]-
[1,2]diazepin-11-one systems 39, 40, and 43 (Scheme 8).

Scheme 8. 2,2'-Dinitrodiphenylmethanes 41, photosynthon for 2,1-benzisoxazole 38, dibenzo[c,f]-
[1,2]diazepin-11-one 39, 40, 43 and acridone systems 42

Photoreactions were carried out using Philip HPH 125-W mercury-quartz lamp in a water-cooled
quartz apparatus. Irradiation of 2,2'-dinitrodiphenylmethane 41a in isopropyl alcohol for 25 h
followed by chromatography yielded (Scheme 7) dibenzo[c,f]-[l,2]diazepin-11-one-5-oxide 39a
as the major product (40%). Other products isolated were acridone 42a (20%), dibenzo[c,f]-
[1,2]diazepin-l l-one 5,6-dioxide 40a (15%) and 2,2'-dinitrobenzophenone 44a (4%). The 4,4'-
dichloro and 4,4'-dibromo compounds gave the corresponding N-oxides 39b,c in 35-40% yield. In
the case of bromo derivative (X = Br), acridone 42c could not be isolated but the N-hydroxy
derivative 3,6-dibromo-N-hydroxyacridone 45c was obtained in 15% yield. The dichloro
compound 41b gave both acridone 42b and N-hydroxyacridone 45b, though in lower yield
(Scheme 9).
24

Scheme 9. Photolysis of 2,2'-dinitrodiphenylmethanes 41 in 2-propanol

The above photoreactions could be extended to fluoro, iodo, methyl, methoxy substituents in the
ring and the corresponding products could be synthesized [85-87]. Dibenzo[c,f]-[1,2]diazepin-11-
one-N-oxides 39a-c can be easily converted to the corresponding dibenzo[c,f]-[1,2]diazepin-11-
ones 43a-c by treating with finely divided magnesium metal in ethanol under reflux (Scheme 8)
[84,85]. On the other hand, dibenzo-[c f][1,2]diazepin-11-ones 43a-c can be converted back to
dibenzo-[c f][1,2]diazepin-11-one-N-oxide 39a-c by oxidation with perbenzoic acid (PBA) [88].
Johns et al. obtained dibenzo[c,f]-[1,2]diazepin-11-ones 43 from 2,2'-dinitrobenzophenones 44 by
Cu (I) oxide catalyzed intramolecular reductive coupling of the two nitro groups using glucose as
the reducing agent (Scheme 10) [89].

Scheme 10. Preparation of dibenzo-[c f]-[1,2]diazepin-11-ones 43 and the N-oxides 39
25

Interestingly, by changing the reaction medium and carrying out the reaction in weakly acidic
ethanol (950 mL of ethanol containing 2 mL of conc. H2SO4) irradiation of 41a for 20 h resulted
in 70% conversion of the substrate. Joshua and coworkers were able to separate 3-(2'-nitropheny1)-
2,1-benzisoxazole (38a) in 35% yield. This is an elegant direct protocol to synthesize 3-(2'-
nitropheny1)-2,1-benzisoxazoles 38 in a single step. In addition, about 6% diazepinone N-oxide
(39a), 4% of acridone (42a) and 3% of 2,2'-dinitrobenzophenone (44a) (3%) were also isolated.
The corresponding dibromo and dichloro-2,1-benzisoxazoles (38b) and (38c) were obtained from
the dichloro and dibromo analogues in 45-50% yield. This acid-catalyzed photochemical reaction
thus provided a novel and easy protocol to synthesize 2,l-benzisoxazoles 38 (Scheme 11), which
are otherwise difficult to obtain. Therefore, 2,2'-dinitrodiphenylmethanes 41 can serve as ideal
substrates for the synthesis of 3-(2'-nitropheny1)-2,1-benzisoxazoles 38, dibenzo[c,f]-
[l,2]diazepin-11-one-5-oxide 39 and dibenzo[c,f]-[1,2]diazepin-ll-one-5,6-dioxide 40 in 15-50%
yields though the corresponding acridones 42 and 2,2'-dinitrobenzophenones 44 were not obtained
in significant amounts.

Scheme 11. Photolysis of 2,2'-dinitrodiphenylmethanes 41 in EtOH-H2SO4

26

Later studies [90] showed that irradiation of 3-(2'-nitropheny1)-2,1-benzisoxazole 38a leads to a
mixture of dibenzo[c,f]-[l,2]diazepin-11-one-5-oxide 39a, dibenzo[c,f]-[1,2]diazepin-11-one-5,6-
dioxide 40a, acridone 42a and N-hydroxyacridone 45a (Scheme 12). It is intriguing to note that
presence of the neighboring nitro group is indeed highly instrumental in the formation of these
products similar to those obtained from 2,2'-dinitrodiphenylmethanes (Scheme 9 and 11).

Scheme 12. Phototransformation of 3-(2'-nitropheny1)-2,1-benzisoxazole 38a in EtOH-H2SO4

Although the protection of carboxylic acids as 2-nitrodiphenylmethylesters (vide supra) and
efficient light induced deprotection have been studied by many groups as already mentioned,
phototransformations on 2-nitrodiphenylmethyl function has been investigated by only few
researchers. Similar results were obtained from 2,2'-dinitrodiphenylmethanol and the esters except
that the major product isolated in the case of carbinols were 2-nitro-2'-nitrosobenzophenones [91-
93].

1.8. Photolysis of 2-nitrodiphenylmethanes
In order to avoid the influence of the second nitro group in the diphenylmethane framework,
phototransformation of 2-nitrodiarylmethanes 46 were also studied by Joshua and coworkers [94].
The reaction was carried out in both dry isopropanol and acidified ethanol and 95% conversion
27

was observed in 3-5 h. It resulted in the formation of benzoic acids 47 as the major products (52-
63%) with 3-phenyl-2,1-benziosxazoles (38, 14-23%) and acridones (42, 3-10%) as minor ones
(Scheme 13). However, the substrate is useful to obtain the corresponding benzisoxazoles without
the nitro group in noticeable amounts despite no improvement of the yield was observed. Using
acidified ethanol as solvent, the yield of benzisoxaloes could be slightly increased. Though, the
synthesis of benzoic acids by this photochemical route is of little value, direct synthesis of
benzisoxazoles and acridones, albeit in lower yields, by this photocyclization strategy draws our
attention as it can be useful in new drug discovery and synthesis in the pharmaceutical arena.

Scheme 13. Phototransformation of 2-nitrodiarylmethanes 46

Mechanistic studies on the phototransformation of 2,2'-dinitrodiphenylderivatives, conducted by
nanosecond and picosecond laser flash photolysis studies [95] point to hydrogen abstraction, the
formation of the quionoid species, and the formation of the cyclic intermediate as the main steps
involved as revealed by previous studies (Scheme 5).

1.9. Photolysis of 1,2-bis(2-nitrophenyl)ethane
The photochemistry of 1,2-bis(2-nitrophenyl)ethane 48, next homolog of 2,2-dinitrodiphenyl-
methane 41, was also studied later [96]. It is worth noticing that the products were obtained from
the intermolecular redox processes of the nitro group unlike 2,2-dinitrodiphenylmethane in which
28

intramolecular redox reaction is mainly reported to occur. Irradiation of a solution of 48 (1 g) in
benzene (500 mL) afforded a mixture of 2-nitrobenzoic acid 49 (16%), 2-nitrobenzyl-2'-
nitrophenyl ketone 50 (16%), 2,2'-dinitrobenzyl 51 (23%) and, dibenzo(c,g)(1,2)diazocin-5,6-
dione-N,N-dioxide 52 (19%). This offers a direct and convenient method to obtain 52, though the
yield is not high (Scheme 14).

Scheme 14. Phototransformation of 1,2-bis(2-nitrophenyl)ethane 48

1.10. Photolysis of 2-nitrostilbenes
As early as 1947, Dimroth, et al. [97] had reported that o-nitrostilbenes 53 absorbing at long wave
lengths produce isatogens 54 upon irradiation. In this case, unlike intramolecular hydrogen
abstraction as in 2-nitrobenzyl systems, the course of the reaction observed is changed to
photocyclization. Splitter and Calvin [98] synthesized a series of trans-stilbene derivatives such
as 2-nitro-, 2,4-dínitro-, and 2,4,6-trinitrostilbenes to study their isomerization to the
corresponding cis-forms. Intriguingly, some o-nitrostilbenes [98,99] were found on irradiation to
give substituted isatogens instead of the expected cis-isomers, when substituted by electron-
releasing groups at the p-position of the ring not carrying the nitro group. A study of the kinetics
29

of the reaction and the isolation of products indicated that both ionic and radical steps were
involved in the photocyclization. The substrate 53 is highly photoactive due to the presence of two
more nitro groups, however, with other derivatives 55, photoreaction was conducted in the
presence of iodine to promote the photo-redox process (Scheme 15).

Scheme 15. Synthesis of isatogens 54 from 2-nitrostilbenes 53 through nitro-ene
photocycloaddition

Another example for similar photoreaction is the photocyclization of 4-(2'-
nitrobenzylidene)-4H-pyrans 58 to indolines 59 by intramolecular cycloaddition and subsequent
rearrangements [100]. The resulting indolines undergo further light induced redox reaction and
rearrangement to the carboxylic acid 60 (Scheme 16).

30

Scheme 16. Intramolecular photocyclization of 4-(2'-nitrobenzylidene)-4H-pyrans 58
1.11 Conclusion
Studies in the past show that the photochemical transformation of 2-nitrodiarylalkyl systems
unveils a convenient protocol for easy access to many N-heterocycles such as benzisxazoles,
dibenzodiazepinone and acridone systems. While developing new photochemical methods, many
reported photochemical reactions can be revisited as their full synthetic potential is yet to be fully
realized. By choosing suitable substrates carrying chromophores with significant photosensitivity
such as 2-nitrobenzyl chromophore and the right photolytic conditions, direct synthesis of many
novel heterocycles and compounds that cannot be easily synthesized can be achieved. However,
their synthetic utility has not been explored. I have been investigating the photochemistry of a
series of α-trifluormethylated 2-nitrobenzyl systems and their synthetic potential for achieving
trifluoromethylated N-heterocycles such as benzoxazoles and trifluoroacetyl azobenzene
derivatives. I have found that, indeed, these systems also follow similar pathways and provide an
elegant protocol for direct access to these compounds vide infra.
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agents, WO Patent WO2009091324 A1, 2009.
[78] Lyssikatos, J. P.; Greca, S. D. L.; Yang, B. V. Quinolin-2-one derivatives useful as anticancer
agents, U.S. Patent 6,495,564 B1, 2002.
[79] Michael, P. M. Quinoline, quinazoline and acridone alkaloids. Nat. Prod. Rep. 2008, 25,166-
187.
[80] Michael, P. M. Quinoline, quinazoline and acridone alkaloids. Nat. Prod. Rep. 2007, 24 223-
246.
[81] Ehlrich, P.; Bauer, H. Über 3.6-diamino-seleno-pyronin (3.6-diamino-xanthoselenonium).
Ber. Dtsch. Chem. Ges. 1915, 48, 502-507.
[82] Theilacker, W.; Korndörfer, O. Die synthese von 2,2'-hydrazodiphenylmethan. Tetrahedron
Lett. 1959, 1, 5-6.
[83] Catala, A.; Popp, F. D. Diazepines. I. 3,8‐Dihalo‐11H‐dibenzo[c,f]‐[1,2] diazepines. J.
Heterocyclic Chem. 1964, 1, 178-181.
[84] Joshua, C. P.; Ramdas, P. K. Photochemistry of 2,2'-Dinitrodiphenylmethanes: Irradiations
in neutral, acidic and alkaline media. Aust. J. Chem. 1976, 29, 865-867.
[85] Jacob, D.; Joshua, C. P. Photochemistry of 4,4'-difluoro/iodo-2,2'-dinitrodiphenylmethanes.
J. Ind. Chem. Soc. 1990, 67, 250-253.
[86] Christudhas, M.; Joshua, C. P. Photochemistry of 2,2'-Dinitrodiphenylmethanes. II:
Irradiation of 5,5'-dimethyl2,2'-dinitrodiphenylmethanes in neutral, acidic and alkaline
media. Aust. J. Chem. 1982, 35, 2377-2381.
40

[87] Joshua, C. P.; Christudhas, M. Photochemistry of 2,2'-dinitrodiphenylmethanes: Part III.
Irradiations of 5, 3'-dimethyl-2,2'-dinitrodiphenylmethanes in neutral, acidic and alkaline
media. Ind. J. Chem. 1983, 22B, 432-436.
[88] Amiet, R. G.; Johns, R. B. Azepinones. III N-oxidation and subsequent nitration of
dibenzodiazepinone. Aust. J. Chem. 1967, 20, 723-729.
[89] Johns, R. B.; Markham, K. R. The synthesis of dibenzo[c,f][1,2]diazepin-11-one. J. Chem. Soc.
1962, 3712-3717.
[90] Christudhas, M.; Joshua, C. P. Photorearangement of 3-(2'-nitrophenyl)-2,1-benzisoxaoles-
an example of neighboring group interaction of photoexcited nitro group. Ind. J. Chem. 1983,
22B, 325-327.
[91] Jacob, D. E.; Joshua, C. P. Photolysis of 2,2'-dinitrodiphenylcarbinols in neutral, acidic and
basic media. Ind. J. Chem. 1984, 23B, 811-814.
[92] Mathew, T.; Joshua, C. P. Photolysis of benzoyl esters of 2,2’-dinitrodiphenylcarbinols in
neutral and basic media. J. Photochem. Photobiol. A. Chem. 1991, 60, 319-324.
[93] Mathew, T.; Joshua, C. P. Photolysis of acetyl esters of 2,2’-dinitrodiphenylcarbinols in
protic and aprotic solvents. Res. Chem. Intermediat. 1991, 16,189-198.
[94] Christudhas, M.; Jacob, D. E.; Joshua, C. P. Photolysis of 2-nitrodiphenylmethanes in
isopropanol and acidified aqueous ethanol. Ind. J. Chem. 1984, 23B, 815-817.
[95] Mathew, T.; Ramaiah, D.; Joshua, C. P.; Weir, D.; George, M. V. Nonosecond and
picosecond laser flash photolysis studies of 2,2'-dinitrodiphenylmethanes. J. Photochem.
Photobiol. A Chem. 1993, 70, 245-251.
[96] Rajasekharan, K. N.; Sulekha, A. Photoreactions of 1,2-bis(2-nitrophenyl)ethane. Ind. J.
Chem. 1997, 36B, 697-699.
41

[97] Dimroth, K. Über eine Lichtreaction in der Stilbenreihe. Angew. Chem. 1947, 59, 176.
[98] Splitter, J. S.; Calvin, M. The photochemical behavior of some o-nitrostilbenes. J. Org.
Chem. 1955, 20, 1086-1115.
[99] Lehznoff, C. C.; Hayward, R. J. Photocyclizations reactions of aryl polyenes. IV. The
synthesis of isatogen and isatogen-like compounds. Can. J. Chem. 1971, 49, 3596-3601.
[100] Van Allan, J. A.; Farid, S.; Reynolds, G. A.; Chang, S. C. Photochemical conversion of 4-
(o-nitrobenzylidene)-4H-pyrans to 1-hydroxy-3-oxospiro[indoline-2,4'-4'H-pyran]
derivatives. J. Org. Chem. 1973, 38, 2834-2838.

42

Chapter 2: 2-nitrophenyl-α-trifluoromethyl carbinols as smart
synthons for novel fluoroorganics
2.1 Introduction
The rich photochemistry of o-nitrobenzylic systems has been extensively explored and utilized in
the past few decades for convenient application as effective photoremovable protecting groups,

[1-
7] which make these systems a vital tool in chemical biology [8] such as DNA polymerase
technology and in synthesis of photo-labile caged compounds [9-11]. o-Nitrobenzylic group has
been effectively used for the safe photochemical release of acids, alcohols, amines, phosphates and
ketones. In solid state peptide synthesis, it has been used as a very efficient photocleavable
protecting group. In 1901, Ciamician and Silber [12] reported the intramolecular photoredox
transformation of o-nitrobenzaldehyde to o-nitroso benzoic acid. Years later, further studies were
carried out by Spiteller [13], Morrison

and Migadolf [14] on similar systems. Time-resolved
experiments by George and Sciano, [15] Yip and Sharma, [16] Gilch and coworkers [17] have
suggested that the primary process among several elementary processes involved in the
phototransformation of ortho-nitrobenzylic systems is the hydrogen transfer from the substituent
with C-H functionality in the ortho position to the nitro group during irradiation (Scheme 1).

Scheme 1: Intramolecular photoredox processes in o-nitro-benzylic systems
CH
2
OH
NO
2
CHO
NO
NO
2
H
R
R
'
OH
R
R'
NO
hv
hv
CHO
NO
2
NO
hv
1. R = H; R
'
= OH
2, R + R
'
= O
OH
O
(a)
(b)
43

There is a huge drive towards the synthesis of fluoroorganic molecules as many of them are very
valuable in medicinal and material chemistry. In pharmaceutical chemistry, introduction of fluorine
and perfluoro groups in drug molecules generate significant changes in conformation, lipophilicity,
metabolic stability and pharmacokinetic properties that are highly desirable in medicinal chemistry
[18, 19].These changes are attributed to the high electronegativity of fluorine and its small size,
which is comparable to hydrogen [20]. So far, over 20% of approved pharmaceutical drugs contain
one or more fluorine atoms, while in the case of newly registered agrochemicals, it is even higher
(~30%) [21, 22]. Some of the well-known drugs include the targeted chemotherapy drug Sorafenib
(Nexavar) A, selective Bcr-Abl kinase inhibitor Nilotinib (Tasigna) B, non-steroidal anti-
inflammatory drug Celecoxib (celebrex) C, the cholesterol-lowering compound atorvastatin
(Lipitor) D, the antidepressant fluoxetine (Prozac) E and the antibiotic ciprofloxacin (Ciprobay) F
among the popular fluorine containing drugs (Figure 1). Strong dipoles introduced by partial
fluorination cause changes in electrical effects which are useful in the development of ferroelectric,
antiferroelectric and liquid crystal materials [23].

Figure 1. A few widely used fluorine-containing drugs
N
Ph
PhHNOC
i-Pr
HO
HO
CO
2
H
D: Atorvastatine (Lipitor)
N
N
CF
3
Me
H
2
NO
2
S
F
C: Celecoxib (Celebrex)
F
3
C
O NHMe
E: Fluoxetine (Prozac)
F: Ciprofloxacin (Ciprobay)
N
OH
O
N
HN
F
O
N
N
O
H
N
CF
3
NH
N
N
Me
N
N
O
H
N
H
N
CF
3
Cl
O
NHMe
O
B: Nilotininb (Tasigna)
Me
A: Sorafenib (Nexavar)
44

Scheme 2. Photochemical transformation of 2,2'-dinitro-diphenylmethanes to N-heterocycles
Our group’s continued interest in the development of efficient synthetic approaches for fluorination
and fluoromethylation of a wide range of organic substrates prompted us to search for simple and
convenient protocols. As earlier studies on the photochemical transformation of 2-nitrobenzyl
derivatives, especially 2,2-dinitrodiphenyl-methane derivatives 3 [24-28] showed that direct
access to heterocycles such as diazepines, diazepine-N-oxides, acridines and their derivatives
could be achieved (Scheme 2), I became curious to examine the photochemistry of α-
trifluoromethyl/perfluorophenyl-2-nitrobenzyl alcohols to see if I could exploit their rich
photochemistry to generate novel trifluoromethylated substituted arenes. While there have been
several approaches, where the trifluoromethylated 2-nitrobenzyl systems have been used as
photoprotecting groups, very few studies on their application as useful photosynthons exist.
NO
NO
2
O
NO
NO
2
N N
O
O
N
O
OH
NO
2
Y
N
O
N
O
Y
OH
NO
NO
HO
H X
H OH
OH
NO
NO O
O
N N
O
O
H
+
hν
N N
O
NO
2
NO
2
O
N
O
H
NO
2
NO
2
Y
X
X = H
Y = H, NO
2
3
X = OH
Y = NO
2
C
6
H
5
CO
2
H
N
O
H
+
+
hν
45

Studies published recently on the use of 2-nitrophenyl-α-trifluoromethyl carbinol as an efficient
photoprotecting group [11] caught my attention and the effective photocleavage/deprotection steps
further sparked my interest to investigate the transformation occurring to 2-nitrophenyl-α-
trifluoromethylcarbinol motif and its synthetic utility.
Results and Discussion

2.2. Steady-state photolysis of 2-nitrophenyl-α-trifluoro-methyl carbinols in 2-propanol:
synthesis of 2,2'-bis(trifluoroacetyl)azoxyarenes
As trifluoromethylated o-nitrobenzyl alcohols can be easily achieved by trifluoromethylation of
the corresponding aldehydes using Ruppert-Prakash reagent, I decided to examine initially the
photoreaction of the simple trifluoromethylated alcohol, 2-nitrophenyl-α-trifluoromethyl carbinol
4a, synthesized by the trifluoromethylation of 2-nitrobenzaldehyde [29-31]. As this
trifluoromethylated carbinol absorbs in the UV-B region, in my initial studies, I irradiated 4a and
its derivatives using a medium pressure Hg lamp with a pyrex glass filter. However, Rayonet
reactor, being more convenient for irradiation with monochromatic lamps, was chosen for further
studies. Irradiation using 300 nm phosphorous lamps provided products with similar or better
yields depending on the nature of the solvent. I carried out the photolysis in three solvents 2-
propanol, dimethyl sufoxide (DMSO) and acetonitrile.
I started the photolytic studies using 2-nitrophenyl-α-trifluoromethyl carbinol by irradiating it in
2-propanol using 100 W medium pressure Hg lamp with a pyrex glass filter. After irradiation for
1 h, aliquots of the mixture were analyzed using
19
F NMR. This showed the formation of a mixture
of products, though with low selectivity. Irradiation for 5 h could afford 20% of a major product,
which was identified as 2,2-bis(trifluoroacetyl)azoxybenzene. Since the reaction was not very
clean, I switched over to a Rayonet reactor fitted with 300 nm monochromatic lamps and the
46

solution was photolyzed for 4 h. Irraditiation of a solution of 2-nitrophenyl-α-trifluoromethyl
carbinol in 2-propanol for 4 h in a Rayonet photoreactor using 300 nm light resulted in the
formation of deep red solution, which on
19
F NMR analysis showed the formation of a major
product. After separation and identification, I was very intrigued to know that it is the
corresponding 2,2'-bis(trifluoroacetyl) azoxybenzene 5a. To the best of my knowledge, this is the
first report on the synthesis of trifluoroacetylated azobenzene-N-oxide by a simple one-step
method as shown (Scheme 3).
While the general route to oxidation of the trifluoromethyl groups to trifluoroacetyl groups
involves the use of harsh reaction conditions even mild reaction conditions need more than
stochiometric addition of an oxidants [30-37]. This intramolecular photoredox process smoothly
oxidizes the trifluoromethylated alcoholic group to the corresponding trifluoroacetyl group,
eliminating the need for an external oxidant. Azoxy compounds exhibit photochromic properties,
find applications in non- linear optics and as dopants materials used in liquid crystals, [38-43] as
substrates for synthesis of heterocyclic compounds, [44, 45] some derivatives display retinoid and
anti-androgenic activity [46, 47].

Therefore, direct

synthesis of

trifluoroacetyl derivatives drew my
keen attention.

Scheme 3. Photolysis of 2-nitrophenyl-α-trifluoromethyl carbinol: direct access to 2,2'-
bis(trifluoroacetyl)azoxy-benzenes
CF
3
OH
NO
2
N
N
O
O F
3
C
CF
3
O
2-Propanol
hν
4a 5a
47

It is evident that its formation occurs by an intramolecular photoredox reaction in which the
photooxidation of trifluoromethylcarbinol to trifluoroacetyl group by the excited nitro group with
its simultaneous photoreduction to nitroso group. Nitrosoarenes, being significantly photoactive,
undergoes subsequent photoreductive coupling to form the corresponding azoxyarene product
[48]. Another product in noticeable amount could not be separated due to decomposition. These
azoxy arenes are characterized by two sharp singlets with equal integration in the region -77 to -
71 ppm. The structures were properly characterized by spectral analysis (
1
H,
13
C,
19
F NMR) and
were further established by X-ray crystallographic analysis (Figure 2, 3).

Figure 2.
19
F NMR spectrum and X-ray crystal structure of 5a
-77.6 -77.2 -76.8 -76.4 -76.0 -75.6 -75.2 -74.8 -74.4 -74.0 -73.6 -73.2 -72.8 -72.4
f1 (ppm)
1.04
1.00
-76.38
-73.14
N
N
O
O F
3
C
CF
3
O
48

Table 1 shows the result of irradiation of the fluorinated carbinols 4a-h in 2-propanol. As shown,
the solutions of halogenated and naphthyl analogs of 2,2,2-trifluoro-1-(2-nitrophenyl)ethanol 4a-
h in 2-propanol on irradiation with 300 nm gave the corresponding azoxy products 5a-g in good
yields. It is noteworthy that for the formation of each molecule of the azoxyarene product, two
molecules of the substrate were required. In the case of 4e with methoxy substitution at the para
position, the yield of the azoxy product was reduced to 2-4%, giving the trifluoromethylated
isoxazoline 6e as the major product. However, for 4g with two methoxy substituents, para to both
nitro and carbinol functionalities, azoxy product 5g was obtained as the sole product.

5f 5h
Figure 3. X-ray crystal structures of 5f and 5h

As seen in Table 1, apart from unsubstituted and halogen substituted 2,2'-
bis(trifluoracetyl)azoxybenzenes, direct synthesis of 2,2'-bis(trifluoracetyl)azoxynaphthalene 5h
was also made possible by this very convenient photochemical method albeit in lower yield.

49

Table 1. Synthesis of 2,2-bis(trifluoroacetyl)azoxyarenes by the photolysis of 2-nitrophenyl-α-
trifluoromethyl carbinols in 2-propanol

CF
3
OH
NO
2
N
N
O
O F
3
C
CF
3
O
2-Propanol
hν
CF
3
OH
NO
2
N
N
O
O F
3
C
CF
3
O
CF
3
OH
NO
2
F
N
N
O
O F
3
C
CF
3
O F
F
CF
3
OH
NO
2
Cl
CF
3
OH
NO
2
Br
CF
3
OH NO
2
N
N
O
O F
3
C
CF
3
O Cl
Cl
N
N
O
O F
3
C
CF
3
O Br
Br
N
N
O
O F
3
C
CF
3
O
Substrate (4a-h) Condition
-Time [h]
N,N-Oxide (5a-h)
A: 40
B: 20
A: 25
B: 16
A: 35
B: 18
A: 37
B: 37
A: 23
B: 4
A: 5
B: 5
A: 5
B: 7
A: 4
B: 4
A: 5
B: 5
A: 2
B: 7
CF
3
OH
NO
2
MeO
N
N
O
O F
3
C
CF
3
O MeO
OMe
A: 4
B: 2
A: 4
B: 4
Entry
a
b
c
d
e
h
CF
3
OH
NO
2
MeO
N
N
O
O F
3
C
O MeO
OMe
A: 50
A: 3.5
f
MeO
OMe
OMe
CF
3
OH
NO
2
N
N
O
O F
3
C
CF
3
O
A: 4 g
MeO
OMe
Condition A- 300 nm Rayonet reactor
Condition B- Hg Lamp with pyrex filter
A: 16
OMe
CF
3
R
1
R
2
R
1
R
2
R
1
4 5
Percentage
Conversion
50

2.3 Synthesis of isobenzoxazolines

Scheme 4. 2-Nitrophenyl-α-trifluoromethyl carbinol, an efficient photosynthon for solvent-
controlled synthesis of 2,2'-bis(trifluoroacetyl)azoxyarenes, 2-trifluoroacetyl nitrosoarenes and
trifluoromethylated isoxazolines
To explore the synthetic utility of this photoprocess, I continued the study with a series of 2-
nitrophenyl-α-trifluoromethyl carbinols using different solvents. Therefore, as the next approach,
I chose the highly polar, aprotic solvent DMSO as the solvent for irradiation. Interestingly, I
observed a fascinating phenomenon when there was a methoxy group located para to the nitro
group. When the para-methoxy substituted (para to nitro group) substrates were irradiated in
DMSO as solvent, intramolecular cyclization with the elimination of a molecule of methanol
occurred leading to the formation of a trifluoromethylated isoxazoline 6. More intriguingly,
changing the solvent to acetonitrile led to the formation of 2-trifluoroacetyl nitrosoarenes or their
hydrates as the major products (Scheme 4). Molecules containing the isoxazoline core are found
CF
3
OH
NO
2
N
N
O
O F
3
C
CF
3
O
hν
R
1
hν
CH
3
CN
R
1
R
1
CF
3
NO
R
1
+
O
CF
3
HO
NO
R
1
OH
F
3
C
N
O
OH
O
2-Propanol
hν
DMSO
R = OMe
N
O
CF
3
F
3
C
H
N
O
N
H
CF
3
O
Cl
Afoxolaner
N
O
Cl
F
3
C
H
N
O
N
H
CF
3
O
Cl
Cl
Fluralaner
4
5
6
7 8
R
2
R
2
R
2
R
2
R
2
R
2
51

to exhibit significant antiplatlet activity [49, 50]. These types of molecules also exhibit insecticidal
properties; Afoxolaner (G) and Fluralaner (H) are commercial drugs used to treat fleas in mammals
(Scheme 4) [51, 52].Nitroso compounds serve as reactants for various synthetic transformations
such as those involving nitroso aldol reactions [53-55], ene reactions[56], cycloaddition etc [55]
They are also used as effective metal coordinating ligands [57] and antiviral compounds [58].
Figure 4.
19
F NMR spectrum and X- ray crystal structure of 6e

While 4a formed the corresponding trifluoroacetyl nitroketone 7e with a methoxy group present
para to the nitro group, it eventually formed the corresponding isooxazoline 6e by the elimination
of a molecule of methanol. The 4,5-dimethoxy substituted carbinol 4f, which formed the azoxy
arene 5f previously in 2-propanol, is now transformed to isoxazoline 6f by irradiation in DMSO. I
was very delighted to see that methoxy substituted substrate 5i with an adjacent difluoromethoxy
- 2 0 0 - 1 9 0 - 1 8 0 - 1 7 0 - 1 6 0 - 1 5 0 - 1 4 0 - 1 3 0 - 1 2 0 - 1 1 0 - 1 0 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0
f 1 ( p p m )
- 8 4 . 5 9

O
N
O
CF
3
OH

52

substituent also formed the corresponding difluoromethoxy substituted isoxazoline 6i. Formation
of the isoxazolines were identified by the formation of a distinct singlet in the
19
F NMR spectra
between -85 to -83 ppm depending on the substrate and solvent (Figure 4). Formation of the
isoxazolines noticed during the irradiation in 2-propanol in minute concentration reached
maximum concentration when the solvent was switched to DMSO.

Table 2. Synthesis of trifluoromethylated benzisoxazoles by the photolysis of 2-nitrophenyl-α-
trifluoromethyl carbinols in DMSO.
To obtain these compounds in substantial yields, after irradiating the solution at a proper
wavelength (300 nm) for a specific period of time with monitoring the fading of substrate
concentration, the solution had to be kept undisturbed under dark for a period of 72-168 h to avoid
any secondary photoprocesses. This allows the formation and rearrangement of the intermediate
Substrate (4e-h)
Time [h]
isobensoxazoline (6e-h) Yield (%)
CF
3
OH
NO
2
MeO
37
Entry
e
CF
3
OH
NO
2
MeO
f
MeO
CF
3
OH
NO
2
i
HF
2
CO
CF
3
OH
NO
2
MeO
hν (300 nm)
DMSO
O
N
O
CF
3
OH
R
2
R
2
= H, OMe, OCF
2
H
t
i
O
N
O
CF
3
OH
R
2
t
s
MeO
O
N
O
CF
3
OH
O
N
O
CF
3
OH
4.5 72
22 5.25 168
MeO
HF
2
CO
t
i
= Time of irradiation, t
s
= Time kept undisturbed in the dark
4e,f,i
6e,f,i
4
48
12
53

with the elimination of a molecule of methanol to form the isobenzoxazolines 6e,f,i (vide infra-
Scheme 7).
Fascinated by the events in DMSO as solvent, I decided to change the solvent to CH3CN, an aprotic
solvent with lower polarity. Irradiation of carbinol 4a showed the formation either of the two major
products, which were identified as 2-trifluorocetyl nitrosoarene 7a and its hydrate 8a. Further
studies with the halogenated and the methoxy substituted carbinols revealed 4a, 4b and 4e yielded
the corresponding 2-trifluorocetyl nitrosoarene 7a, 7b and 7e, while 4c and 4d formed the hydrates
8c and 8d. (Scheme 5, Table 3).

Scheme 5. Formation of 2-trifluorocetyl nitrosoarenes 7a-e and the hydrates 8a-e from photolysis
of 4a-e in MeCN; X- ray crystal structure of 8d' (the dimer of the hydrate 8d)
Evaporation of acetonitrile from the photolysate of 4d yielded solid, which was found to be the
dimer 8d'of the trifluoroacetyl nitroso ketone 8d. This is soluble in DMSO also. The NMR spectra
recorded for this solid were similar to the intermediate observed in the DMSO experiments. Its
structure was also determined by X-ray single crystal analysis (Scheme 5). However, when the
CF
3
OH
NO
2
R
1
CF
3
NO
R
1
+
O
CF
3
HO
NO
R
1
OH
hν (300 nm)
CH
3
CN
R
1
= H, F, Cl, Br, OMe ; R
2
=H
Solid obtained after solvent
evaporation and crystallization
in DMSO
CF
3
N
R
1
N
F
3
C
R
1
HO
OH
OH
HO
O
O
R
1
= H, F, OMe ; R
2
=H R
1
= Cl , Br: R
2
= H
CHCl
3 CF
3
NO
R
1
O
4
7 8
R
2
R
2
R
2
8c’, 8d’
R
2
R
2

8d’
54

hydrate is left in CDCl3 or excess CHCl3, it gradually dissolved and formed the 2-triflluoroacteyl
nitrosoarene. This could be attributed to dehydration due to the residual acids in these solvents.

Table 3. 2-Trifluorocetyl nitrosoarenes 7a-e and their hydrates 8a-e from the irradiation of 4a-e in
MeCN
2.4. Transient absorption spectroscopy
To better understand the mechanism of the photoreaction, femtosecond UV-pump/Vis-probe
transient absorption spectroscopy was used to study the transient intermediates involved in the
reaction. The details of the transient absorption apparatus are described elsewhere [59]. Study was
CF
3
OH
NO
2
NO
O
CF
3
CF
3
OH
NO
2
F
CF
3
OH
NO
2
Cl
CF
3
OH
NO
2
Br
Substrate (4a-e)
Time (h)
Nitrosoarene (7a-e) Yield (%)
CF
3
OH
NO
2
MeO
Entry
a
b
c
d
e
CF
3
OH
NO
2
R
1
CF
3
NO
R
1
+
O
CF
3
HO
NO
R
1
OH
hν (300 nm)
CH
3
CN
R
1
= H, F, Cl, Br, OMe:
R
2
= H
Hydrate (8a-e)
NO
OH
CF
3
OH
NO
O
CF
3
NO
OH
CF
3
OH
NO
O
CF
3
NO
OH
CF
3
OH
NO
O
CF
3
NO
OH
CF
3
OH
NO
O
CF
3
NO
OH
CF
3
OH
F
Cl
Br
MeO
F
Cl
Br
MeO
4a-e
7a-e
8a-e
7a- 60*
8a- 0
7b- 27*
8b-0
7c -0
8c-36
7d-0
8d-50
7e-94
8e-0
4
4
4
4
3
* -
19
F NMR yield
R
2
R
2 R
2
55

conducted using 4a in 2-propanol and mixture of water and 2-propanol (Figure 5). At 300 fs, the
shortest delay resolved by our instrument, a broad spectrum is seen that is assigned to the S1 state
of the molecule. In the first ten picoseconds, this spectrum evolves. The evolved spectrum,
consisting of a narrow short wavelength feature (~430 nm) and a broad long wavelength feature,
is assigned as a mixed population of the o-quinonoid singlet and the T1 triplet states. These
assignments are made based on previous works by Yip and Sharma, [60, 61] who illustrated that
the short wavelength feature is associated with the o-quinonoid species and the long wavelength
feature is associated with the triplet state. Overlapping absorption of these two states was similarly
observed by Yip and Sharma.

Figure 5. Transient absorption spectra of 2,2,2-trifluoro-1-(2-nitrophenyl)ethanol 4a in 2-
propanol, 2-propanol with 1% water and 2-propanol with 10% water
2-Propanol 1% Water
10% Water
56

To probe the identities of these features experimentally, water was gradually added to the 2-
propanol solution to observe its effects on the spectral evolution. Addition of water led to an
increased prevalence of the short wavelength feature in the transient absorption spectrum. This is
consistent with the short wavelength feature being assigned the o-quinonoid species, since addition
of water could aid in the proton transfer process necessary for o-quinonoid generation. Oxygen
was also added to the solution to observe its effects on the spectral evolution. Over the temporal
range of the instrument employed (600 ps), there were no spectral changes observed by the addition
of oxygen. While I expect the contributing T1 state to be quenched by the presence of oxygen, it
is possible that such effects take place on longer timescales.
2.5. Steady-state photolysis in DMSO and analysis of the photolysate
On irradiation of 4a in DMSO-d6, an intermediate, which was characterized by the formation of a
peak (quartet) at -84.3 ppm in the
19
F NMR was detected. As the reaction progressed, the peak
corresponding to Cα (to CF3) in the
13
C spectrum moved from 65.1 ppm (J = 31.4 Hz) to 94.0 (J
= 32.4 Hz) ppm on irradiation. This intermediate finally gives rise to the trifluoroacetyl nitroso
ketone 7a.
On irradiation of 2,2,2-trifluoro-1-(5-methoxy-2-nitrophenyl)ethanol 4e in DMSO, a similar
transition was observed. The compound on irradiation formed an intermediate (evidenced by the
appearance of a signal at -84.4 ppm in the
19
F NMR spectrum), which on being left undisturbed
transforms into 6e (Figure 6). As the reaction progressed, monitoring the reaction with
13
C NMR
showed the transformation of quartet corresponding Cα (to CF3) in the alcohol 4e (65.2 ppm) to
the one corresponding to Cα in the intermediate (94.2 ppm) and finally to the one in isoxazoline
6e (103.2 ppm) (Scheme 6, for detailed procedure, see supplementary section).
57

This intermediate was eventually characterized as the hydrated trifluoroacetyl nitroso ketone 8e
obtained when the reactions were carried out in acetonitrile.

Figure 6.
19
F NMR taken at different intervals: A Solution of 4e in DMSO-d6 after irradiation for
2.5 h, showing the formation of intermediate; B irradiated mixture left undisturbed for 24 h
showing transition of the intermediate to 8e; C after 72 h, showing almost complete conversion of
the intermediate to the product 6e
-85.0 -84.5 -84.0 -83.5 -83.0 -82.5 -82.0 -81.5 -81.0 -80.5 -80.0 -79.5 -79.0 -78.5 -78.0
f1 (ppm)
A
B
C
5e
5e
5e
I n t e r m e d i a t e
I nt e r m e di a t e
6e
6e

CF
3
OH
NO
2
MeO

CF
3
HO
NO
MeO
OH

O
N
O
CF
3
OH
58

Figure 7.
13
C NMR taken at different intervals: (A) Solution of 4e in DMSO-d6 after irradiation
for 2.5 h, showing the formation of intermediate; (B) irradiated mixture left undisturbed for 24 h
showing transition of the intermediate to 8e; (C) after 72 h, showing almost complete
conversionof the intermediate to the product 6e

Scheme 6. Synthesis of isoxazoline 6e by the photolysis of 2,2,2-trifluoro-1-(5-methoxy-2-
nitrophenyl)-ethanol 4e in DMSO
- 10 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 1 1 0 1 2 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
A
B
C
CF
3
OH
NO
2
MeO
CF
3
HO
NO
MeO
OH
hν (300 nm)
DMSO
O
N
O
CF
3
OH
Intermediate 4e 8e 6e

O
N
O
CF
3
OH

CF
3
OH
NO
2
MeO

CF
3
HO
NO
MeO
OH
59

2.6. Plausible mechanism
Based on the laser flash photolysis studies, steady state analysis conducted and comparing the
results with previous observations, we suggest that the following plausible mechanism for the
transformations and the rearrangement involved. On irradiation, the nitrochromophore in the
trifluoromethylated o-nitrobenzyl alcohol 4 undergoes n-π
*
excitation to form the excited singlet
state initially. The excited singlet state rearranges to the o-quinoid intermediate 11 which leads to
the cyclic intermediate 12 (Scheme 7).
In 2-propanol, the cyclic intermediate 12 very likely opens to give the corresponding
trifluoroacetyl nitroso product 7, which itself being highly photoactive undergoes photoreductive
coupling to form the trifluoroacetyl azoxy products. It is also possible that in 2-propanol, part of 7
might also get reduced to the corresponding hydroxylamine followed by condensation with nitroso
product 7 to form trifluoroacetyl azoxy products. In 4e, the presence of methoxy group in the para
position enhances the rate of formation of cyclic intermediate 12e during the photoreaction and
incites the elimination of a molecule of CH3OH resulting in 6e. This process is highly favored in
DMSO.
It is quite intriguing to note that a mixture of the nitrosoketone product 7 and its hydrate 8 are
formed when the reaction is carried out in acetonitrile. As the formation of stable hydrates in the
case of aldehydes, ketones and imines containing several electronegative substituents such as
trichloromethy/trifluoromethyl is well known [62-64],

formation of the hydrates 8 is quite
reasonable.

60

Scheme 7. Plausible mechanism leading to photoproducts observed during the irradiation of 4a-i
in various solvents
C
N
hv
CF
3
OH
H
O
O
C
N
CF
3
OH
H
O
O
*
singlet* triplet*
C
N
CF
3
OH
OH
O
T
C
N
CF
3
OH
OH
O
C
N
CF
3
OH
OH
O
T
C
N
CF
3
OH
OH
O
N
O
OH
F
3
C OH
~H ~H
4a-h
10
11 12
9
N
N
O
(Photoreductive
coupling)
NO
CF
3
O
-H
2
O
CH
3
CN
NHOH
CF
3
O
F
3
C O
CF
3
O
2-Propanol
R
1 R
1
R
1 R
1
R
1
R
1
R
1
R
1
R
1
5
R
1
R
1
R
2 R
2
R
2
R
2
R
2
R
2
R
2
R
2
R
2
R
2
R
2
N
OH
F
3
C
OH
O
R
1
8 Nitrosoketone
hydrate
NO
R
1
O
CF
3
N
OH
F
3
C
OH
R
1
N
HO
CF
3
HO
R
1
O
O
R
2
R
2
Dimerization
CHCl
3
7 Nitrosoketone
8c’, 8d’
Solid obtained on removal of solvent
R
2
R
1
+
DMSO
N
O
F
3
C OH
O
4e,f,i
R
2
= H, OMe, CF
2
H
Photolysis of 4e,f,i (R
1
= OMe) in DMSO
R
2
N
OH
F
3
C
OH
O
O
Me
R
2
N
O
O
F
3
C OH
12e,f,i
Cyclic intermediate
C
N
CF
3
OH
H
O
O
O
8e,f,i, Nitrosoketone
hydrate
R
2
Me
O
Me
R
2
hv
(300 nm)
6e,f,i,
H
Isomerization
-CH
3
OH
61

In fact, the hydration ability of trifluoromethylated ketones has been exploited in the development
of many organic synthetic methodologies, recently for the development of histone deacetylase
(HDAC) inhibitors [65] However, as expected, on workup and drying the product, conversion to
the nitroso product occurs gradually. Addition of chloroform/CDCl3 pushes the equilibrium
towards the dehydrated trifluoroacetyl nitrosoarene due the residual acids present in
chloroform/CDCl3. Thus, the formation of the photoproducts could be rationalized based on these
observations.
2.7. Conclusion
Through this approach, the synthetic utility of α-trifluoromethylated o-nitrobenzyl alcohols as
efficient photosynthons toward the synthesis of new series of fluoroorganics with versatile
functional motifs such as trifluoromethylated azoxy arenes, trifluoromethylated isoxazolines and
trifluroacetyl nitroso arenes is revealed. Mechanistic studies by picosecond laser flash photolysis
and monitoring of the steady state photolysate by NMR spectroscopic analysis shed light on the
transient species and intermediates involved in the reaction. My work is the first report
underscoring the importance of re-evaluating the potential of perfluorinated o-nitrobenzylalchols
as photosynthons in addition to their photo-protecting ability. We also anticipate that further studies
in the area will provide key synthetic pathways for direct access to many biologically active small
fluoroorganic molecules of great importance in the pharmaceutical arena in the future.

62

2.8 Experimental Section
General Information
1
H,
13
C,
19
F spectra were recorded on Varian 600 MHz, 500 MHz, 400 MHz NMR spectrometers.
1
H NMR chemical shifts were determined relative to the signal of a residual protonated solvent,
CHCl3 in CDCl3 (δ 7.26) and DMSO in DMSO-d6 (2.50)
13
C NMR chemical shifts were
determined relative to the
13
C signal of solvent, CDCl3 (δ 77.2) or DMSO-d6 (39.5).
19
F NMR
chemical shifts were determined relative to CFCl3 as an internal standard (δ 0.0) when measuring
the alcohols and 2,2'-bis(trifluoroacetyl)azoxy-benzenes. PhCF3 (δ -63.7) was used in all other
19
F
NMR analysis. HRMS data were obtained from HRMS facility at University of Illinois at Urbana-
Champaign MS Lab and University of Southern California. Unless otherwise mentioned, all the
reagents and solvents were purchased from commercial sources. The UV-vis spectra were obtained
using Perkin-Elmer UV-Vis-NIR spectrometer.

Representative procedures
Synthesis of 2-nitrophenyl-α-trifluoromethyl carbinols (2a-2h)
The o-nitrobenzaldehyde (1.0 eq.) was dissolved in commercially available dry THF followed by
addition of (1.2 eq) of TMSCF3. This mixture was cooled in an ice bath and (0.01eq.) of 1 M TBAF
in THF was added dropwise to this mixture.
29
This was then allowed to warm to room temperature
and was stirred for 4-5 hrs. The disappearance of the starting material was monitored by TLC. The
silylated ether was hydrolyzed by stirring it overnight with 1.2 N HCl. The reaction mixture was
extracted thrice in diethyl ether. The combined ether extract was washed with water thrice. It was
then dried using Na2SO4. The diethyl ether was evaporated under reduced pressure to give the
63

crude alcohol which was purified by flash column chromatography using a hexane ethyl acetate
gradient.
Procedure for synthesis of 2,2'-bis(trifluoroacetyl)azoxy-benzenes
Procedure A: A Rayonet reactor equipped with 300nm lamps were used to carry out the reaction.
Quartz tubes containing 1.04 mmol of the fluorinated alcohol dissolved in 100mL isopropanol
were degassed with argon and irradiated. The isopropanol was removed under reduced pressure.
The reaction was repeated twice, and the reaction mixtures were combined. It was purified using
column chromatography. Silica gel was treated with hexane containing 1mL of triethylamine.
Elution was performed using increasing gradients of dichloromethane in hexane (10 - 60%) The
product obtained in the range of 30-50 % DCM and hexane mixture. The fraction containing the
azoxy benzene was further purified further by dissolving it in 4ml of dichloromethane followed by
addition of 10- 15 ml of hexane. It was allowed to recrystallize from this mixture.
Procedure B: We used an immersion well apparatus where a Hanovia Medium pressure mercury
lamp was placed in a water-cooled Pyrex jacket. 2.5mmol of the fluorinated alcohol was dissolved
in 250 mL isopropanol and placed in the reaction vessel surrounding the jacketed lamp. It was
degassed with Argon and irradiated. Isopropanol was removed under reduced pressure. The
product was isolated and purified as mentioned in procedure A.
Procedure for synthesis of trifluoromethylated benzisoxazolines
0.5mmol of the alcohols were dissolved in 10mL of DMSO (reagent grade). It was degassed in
argon and irradiated at 300 nm in a Rayonet reactor. The resulting solution was allowed to stand
undisturbed during which it underwent cyclization to give rise to the resultant trifluromethylated
64

isooxazoline. It was lyophilized and recrystallized. The spectra of the compounds were taken in
DMSO-d6.
Procedures for synthesis of trifluoroacetyl nitroso arene and hydrate of trifluoroacetyl
nitroso benzene.
In Rayonet reactor equipped with 300nm lamps quartz tubes containing 0.5 mmol of the
fluorinated alcohol dissolved in 50 mL acetonitrile was degassed with argon and irradiated. The
acetonitrile was removed under reduced pressure. In general, either the trifluroacetyl nitroso
benzene or its hydrate is formed. The trifluroacetyl nitroso benzene could not be purified and
therefore we used PhCF3 as an internal standard to determine the NMR yield of the product. The
trifluroacetyl nitroso benzene hydrate is purified by washing with small amounts of chloroform to
get a white precipitate which was found to be soluble only in DMSO.
Procedure for steady state photolysis in DMSO
0.7mmol of the alcohol was dissolved in 10g of DMSO-d6. this mixture was degassed with argon
for 20 min and then irradiated at 300 nm. After irradiation the mixture was transferred to an NMR
tube and the progress of the reaction was monitored.
Procedure for UV sample preparation
The trifluoromethyl carbinols were dissolved in isopropanol (65-70mM concentration) and the
UV-vis spectrum was determined. Isopropanol was used for blank measurements.
Procedure for Laser Flash Photolysis study
Transient Absorption Setup
Pump pulses were generated by pumping an OPA (OPerA Solo, Coherent) with the output
of a 1kHz Ti:sapphire amplifier (Legend Elite HE+, Coherent). UV pump pulses were generated
65

by two successive doubling stages of the OPA output. A white light continuum probe was prepared
by focusing the 800nm Ti:sapphire output onto a 3mm thick rotating CaF2 window after the seed
pulse was modulated at 500Hz using an optical chopper. The polarization of the 800nm Ti:sapphire
output was rotated to magic angle with respect to the pump prior to white light generation. The
pump beam was modulated at 250Hz.
A balanced detection scheme was employed to eliminate noise due to fluctuations in the
probe spectrum. The probe arm of the apparatus was split with a 50/50 beamsplitter into two arms:
sample and reference. The beam in the sample arm was focused into the sample and overlapped
with the focused pump beam. The reference arm was also focused onto the sample but in a location
that was not pumped. The probe beams were detected using a 320mm focal length spectrometer
with 150 g/mm gratings (Horiba iHR320) and a 1340 x 100 CCD array (Princeton Instruments
Pixis). Both probe beams were detected on the CCD by displacing their focal planes into the
spectrometer. The sample and reference beams were captured by the top half and bottom half of
the CCD, respectively. The signal resulting from the sample beam contains the transient absorption
and fluctuations due to the instability of the probe. The signal resulting from the reference beam
only contains the fluctuations. The reported transient absorption signals were calculated by
subtracting the reference signal from the sample signal. The focal spot diameters for the pump and
probe were 150 microns and 170 microns, respectively. Cross correlations of the pump and probe
were collected using the nonresonant response of each pure solvent.
Solutions of 115mM in isopropanol were prepared in each of the solvents studied via
transient absorption. The samples were flowed through a fused quartz flow cell with a 0.5mm path
length. The sample was pumped at ~290nm with pulse energies of 50-100 nJ. Samples were purged
with argon except in cases where oxygen was used to observe its impact on triplet states. Samples
66

were pumped at several different powers to check that the signals reported were linear with respect
to pump power.
Spectral data
2,2,2-trifluoro-1-(2-nitrophenyl)ethanol (4a): Yield : 95% Appearance : dark yellow oil

1
H NMR (400 MHz, Chloroform-d) δ 8.03 (dd, J = 8.2, 1.4 Hz, 1H),
7.96 (d, J = 7.9 Hz, 1H), 7.73 (td, J = 7.9, 1.4, Hz, 1H), 7.59 (ddd, J =
8.2, 7.4, 1.5 Hz, 1H), 6.17 (p, J = 6.0 Hz, 1H), 2.93 (d, J = 5.5 Hz, 1H);
19
F NMR (470 MHz, Chloroform-d) δ -78.0 (d, J = 6.3 Hz);
13
C NMR
(126 MHz, Chloroform-d) δ 148.7, 133.7, 130.4, 129.6,128.9, 125.1, 124.0 (q,
1
J C-F = 282.6 Hz),
67.0 (q,
2
J C-F = 32.8 Hz); HRMS (ESI, m/z) for (C8H6F3NO3): calculated 220.0221[M-H]
-
found 220.0179[M-H]
-

2,2,2-trifluoro-1-(5-fluoro-2-nitrophenyl)ethanol (4b): Yield: 64% , Appearance: light orange
crystals
1
H NMR (500 MHz, Chloroform-d) δ 8.13 (dd, J = 9.1, 4.9 Hz, 1H), 7.68
(dd,J=9.2, 2.8 1H), 7.28 – 7.23 (m, 1H), 6.29 (p, J = 5.7 Hz, 1H), 3.03 (d,
J = 5.4 Hz, 1H);
19
F NMR (470 MHz, Chloroform-d) δ -78.1 ,(d, J =
5.86Hz) -101.9 -102.0.(m);
13
C NMR (126 MHz, Chloroform-d) δ 165.2
(d,
1
J = 258.1 Hz), 144.5 , 132.7 (d,
3
J C-F= 8.6 Hz), 128.2 (d,
3
J C-F= 9.5 Hz), 123.7 (q,
1
J C-F =
284.2Hz), 117.4 (d,
2
J C-F= 23.2 Hz), 117.1 (d,
2
J C-F = 25.8 Hz). 66.8 (q,
2
J C-F =32.9 Hz); HRMS
(ESI, m/z) for (C
8
H
4
F
4
NO
3
): calculated 238.0127[M-H]
-
found 238.0129[M-H]
-

CF
3
OH
NO
2
CF
3
OH
NO
2
F
67

2,2,2-trifluoro-1-(5-chloro-2-nitrophenyl)ethanol (4c):. Yield: 48.5%, Appearance: cream
colored crystals
1
H NMR (400 MHz, Chloroform-d) δ 8.02 (d, J = 8.8 Hz, 1H), 7.97 –
7.95 (m, 1H), 7.55 (dd, J = 8.8, 2.3 Hz, 1H), 6.25 (p, J = 5.8 Hz, 1H), 2.95
(d, J = 5.3 Hz, 1H);
19
F NMR (470 MHz, Chloroform-d) δ -78.1 (d, J =
6.1 Hz);
13
C NMR (126 MHz, Chloroform-d) δ 146.7, 140.7, 130.5,
129.9, 129.9, 126.7, 123.7 (q,
1
J C-F 282.7 Hz), 66.7 (q,
2
J C-F = 33.0 Hz); HRMS (ESI, m/z) for
(C
8
H
5
ClF
3
NO
3
): calculated 253.9832[M-H]
-
found 253.9840[M-H]
-

2,2,2-trifluoro-1-(5-bromo-2-nitrophenyl)ethanol (4d) : Yield : 69.8% Appearance: yellow
crystals
1
H NMR (400 MHz, Chloroform-d) δ 8.12 (d, J = 2.3 Hz, 1H), 7.93 (d,
J = 8.7 Hz, 1H), 7.72 (dd, J = 8.7, 2.2 Hz, 1H), 6.24 (p, J = 5.8 Hz, 1H),
2.91 (d, J = 5.4 Hz, 1H);
19
F NMR (376 MHz, Chloroform-d) δ -78.0 (d,
J = 6.1 Hz);
13
C NMR (100 MHz, Chloroform-d) δ 147.2, 133.6, 132.8,
130.9, 129.0, 126.6. 123.7 (q,
1
J C-F = 282.8 Hz) 66.6 (q,
2
J C-F = 33.0 Hz); HRMS (ESI, m/z) for
(C
8
H
5
BrF
3
NO
3
): calculated 297.9326[M-H]
-
found 297.9333 [M-H]
-

2,2,2-trifluoro-1-(5-methoxy-2-nitrophenyl)ethanol (4e): Yield : 60.8%, Appearance: Light
yellow crystals
CF
3
OH
NO
2
Cl
CF
3
OH
NO
2
Br
68

1
H NMR (500 MHz, Chloroform-d) δ 8.13 (d, J = 9.1 Hz, 1H), 7.41 (s,
1H), 7.00 (d, J = 9.2, 2.0 Hz, 1H), 6.35 (pentet, J = 6.0 Hz, 1H), 3.94 (s,
3H), 3.02 (d, J = 5.5 Hz, 1H);
19
F NMR (470 MHz, Chloroform-d) δ -
77.8 (d, J = 6.2 Hz);
13
C NMR (126 MHz, Chloroform-d) δ 163.8 , 141.4
, 132.1 , 128.1 , 123.7 ( q,
1
J C-F = 282.36 Hz), 115.0 , 114.6 , 67.1 (q,
2
J C-F = 32.6 Hz), 56.2;
HRMS (ESI, m/z) for (C
9
H
7
F
3
NO
4
): calculated 250.0327[M-H]
-
found 250.0340[M-H]
-

1-(4,5-dimethoxy-2-nitrophenyl)-2,2,2-trifluoroethan-1-ol (4f): Yield: 75.4% , Appearance:
bright yellow crystals
1
H NMR (400 MHz, Chloroform-d) δ 7.65 (s, 1H), 7.34 (s, 1H), 6.33 (p,
J = 6.0 Hz, 1H), 4.01 (s, 3H), 3.97 (s, 3H), 2.89 (d, J = 5.2 Hz, 1H);
19
F
NMR (564 MHz, Chloroform-d) δ -77.9 (d, J = 6.1 Hz);
13
C NMR (151
MHz, Chloroform-d) δ 153.5, 149.4, 141.2, 124.1 (q,
1
J C-F = 282.8 Hz),
123.6, 110.5, 108.3, 66.9 (q,
2
J C-F = 32.6 Hz), 56.7, 56.6 ; HRMS for (C10H11F3NO5): (ESI M/z)
calculated [M+H] 282.0589; found (M+H)
•+
282.0592

2,2,2-trifluoro-1-(4-methoxy-2-nitrophenyl)ethanol (4g): Yield : 58% Appearance: dark yellow
oil
1
H NMR (400 MHz, Chloroform-d) δ 7.83 (d, J = 8.8 Hz, 1H), 7.51 (d, J
= 2.7 Hz, 1H), 7.23 (dd, J = 8.8, 2.7 Hz, 1H), 6.04 (q, J = 6.7, 6.1 Hz, 1H),
3.90 (s, 3H), 2.95 (s, 1H);
19
F NMR (470 MHz, Chloroform-d) δ -78.1 (d,
J = 6.1 Hz);
13
C NMR (126 MHz, Chloroform-d) δ 160.7, 149.5, 130.7, 124.1 (q,
1
J C-F =
CF
3
OH
NO
2
MeO
CF
3
OH
NO
2
MeO
MeO
CF
3
OH
NO
2
MeO
69

283.5Hz),120.7, 119.8, 110.1, 66.9 (q,
2
J C-F = 32.9 Hz), 56.1; HRMS (ESI, m/z) for (C
9
H
7
F
3
NO
4
):
calculated 250.0327[M-H]
-
found 250.0333[M-H]
-

2,2,2-trifluoro-1-(1-nitronaphthalen-2-yl)ethanol (4h): Yield: 56.7% , Appearance: yellow
crystals

1
H NMR (500 MHz, Chloroform-d) δ 8.08 (dt, J = 8.9, 0.7 Hz,
1H), 7.98 – 7.93 (m, 1H), 7.86 (dd, J = 8.8, 1.2 Hz, 1H), 7.81 – 7.76
(m, 1H), 7.71 – 7.65 (m, 2H), 5.45 (, J = 6.2, 4.7 Hz, 1H), 2.88 (d,
J = 4.9 Hz, 1H);
19
F NMR (470 MHz, Chloroform-d) δ -77.7 (d, J
= 6.0 Hz);
13
C NMR (126 MHz, Chloroform-d) δ 148.2, 134.3 , 131.5 , 129.3 , 128.6 , 128.3 ,
124.2 , 123.6 (q,
3
J C-F = 1.6 Hz), 123.5 , 123.3 (q,
1
J C-F = 280.4Hz), 122.3, 68.2 (q,
2
J C-F = 33.7
Hz); HRMS (ESI, m/z) for (C
12
H
7
F
3
NO
3
)

: calculated 270.0378 [M-H]
-
found 270.0370[M-H]
-

1-(4-(difluoromethoxy)-5-methoxy-2-nitrophenyl)-2,2,2-trifluoroethan-1-ol (4i): Yield: 57 %
, Appearance: yellow crystals

1
H NMR (500 MHz, Chloroform-d) δ 8.00 (s ,1H), 7.50 ( s, 1H) , 6.64
(t, J = 75Hz, 1H) 6.40 (p, J = 5.8 Hz, 1H), 3.07 (d, J = 5.0 Hz, 1H);
19
F
NMR (470 MHz, Chloroform-d) δ -78.0 (d, J = 6.3 Hz), -82.2 – -83.5
(m);
13
C NMR (126 MHz, Chloroform-d) δ 155.6, 140.6, 139.7, 129.1,
123.8 (q,
1
J C-F = 282.8 Hz).119.7, 115.4 (t,
1
J C-F = 264.1 Hz), 112.4, 66.7 (q,
2
J C-F = 32.7 Hz).57.0;
HRMS (EI, m/z) for (C10H8NO5F5): calculated 317.03226 (neutral mass); found 317.03190(M
•+
)
CF
3
OH
NO
2
CF
3
OH
NO
2
MeO
HF
2
CO
70

Spectral data of 2,2'-bis(trifluoroacetyl)azoxy-benzenes
(Z)-1,2-bis(2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5a) :
A: 4a was irradiated 5 hours following procedure A. Percentage Conversion: 40%
B: 4a was irradiated 4 hours following procedure B. Percentage Conversion: 20%
Appearance: light yellow crystals when recrystallized. Can also appear as a light orange semi-
solid.
1
H NMR (500 MHz, Chloroform-d) δ 8.39 – 8.35 (m, 1H),
7.87 (d, J = 7.8 Hz, 1H) , 7.81 – 7.73 (m, 4H), 7.57 – 7.51 (m,
2H);
19
F NMR (470 MHz, Chloroform-d) δ -73.1 , -76.4 ;
13
C
NMR (126 MHz, Chloroform-d) δ 183.8 (q,
2
J C-F = 37.8 Hz),
181.6 (q,
2
J C-F = 36.2 Hz) , 145.5, 142.7, 134.4, 133.1, 132.6, 129.6, 129.3, 129.0 (q,
3
J C-F = 2.8
Hz),128.2 , 126.8, 124.5, 123.4, 116.2 (q,
1
J C-F = 292.32) 115.9 (q,
1
J C-F = 291.06 Hz); HRMS
(ESI, m/z) for (C16H9N2O3F6):calculated 391.0517 (neutral mass); found 391.0509 9(M
•+
)

(Z)-1,2-bis(4-fluoro-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5b):
A: 4b was irradiated 5 hours following procedure A. Percentage Conversion: 25%
B: 4b was irradiated 7 hours following procedure B. Percentage Conversion: 16%
Appearance: Dark orange crystals
N
N
O
O F
3
C
CF
3
O
71

1
H NMR (500 MHz, Chloroform-d) δ 8.35 (dd, J = 9.2, 4.5
Hz, 1H), 8.00 (dd, J = 9.0, 5.0 Hz, 1H), 7.5 (d, J = 8.03Hz
1H), 7.48-7.41 (m, 2H), 7.22 (dd, J = 7.2, 2.7 Hz, 1H);
19
F
NMR (470 MHz, Chloroform-d) δ -73.7 , -76.4 , -103.2, -
107.2;
13
C NMR (126 MHz, Chloroform-d) δ 181.9 (q,
2
J C-F = 38.5Hz), 181.0 (q ,
2
J C-F =37.16
Hz), 164.8 (d,
1
J C-F = 259.9 Hz), 162.0 (d,
1
J C-F = 255.7 Hz), 141.4 , 138.1 (d,
4
J C-F = 3.8 Hz),
131.9 (d,
3
J C-F = 7.9 Hz), 129.7 (d,
3
J C-F = 7.1 Hz), 127.2 (d,
3
J C-F = 8.3 Hz), 125.9 (d,
3
J C-F=
9.4 Hz), 121.0 (d,
2
J C-F = 22.3 Hz), 119.4 (d,
2
J C-F = 23.2 Hz), 116.2 (q,
4
J C-F = 2.5 Hz), 116.0
(q =
4
J C-F 2.6 Hz), 115,9 (q,
1
J C-F 290.3 Hz), 115.9 (d,
2
J C-F = 25.9 Hz), 115.7 (q,
1
J C-F 290.3
Hz); HRMS (ESI, m/z) for (C16H7N2O3F8) :calculated 427.0329 ; found 427.0327 (M
•+
)

(Z)-1,2-bis(4-chloro-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5c):
A: 4c was irradiated 4 hours following procedure A. Percentage Conversion: 35%
B: 4c was irradiated 4 hours following procedure B. Percentage Conversion: 18%
Appearance: cream colored crystals
1
H NMR (500 MHz, Chloroform-d) δ 8.27 (d, J =
8.8,Hz,1H), 7.91 (d, J = 8.71 Hz, 1H), 7.76 (m, 1H),
7.71 (dd, J = 8.8, 2.4, 2H), 7.48 (d, J = 2.2 Hz, 1H);
19

F NMR (470 MHz, Chloroform-d) δ-73.6 ,-76.3;
13
C
NMR (126 MHz, Chloroform-d) δ182.3 (q,
2
J C-F = 38.5 Hz),181.1 (q ,
2
J C-F = 37.3Hz) , 143.7,
140.2, 140.1, 135.9, 134.0, 132.5, 132.5, 131.0, 129.2, 128.7 (q,
3
J C-F = 2.6 Hz), 128.4, 126.1,
N
N
O
O F
3
C
CF
3
O Cl
Cl
N
N
O
O F
3
C
CF
3
O F
F
72

124.6, 115.9 (
1
J C-F, J = 295.4 Hz) 115.7 ( q,
1
J C-F = 290.5 Hz); HRMS (ESI, m/z) for
(C16H7N2O3F6Cl2):calculated 458.9738 (neutral mass); found 458.9732 (M
•+
)

(Z)-1,2-bis(4-bromo-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5d):
A: 4d was irradiated 5 hours following procedure A. Percentage Conversion: 37%
B: 4d was irradiated 5 hours following procedure B. Percentage Conversion: 37%
Appearance: light yellow crystals
1
H NMR (500 MHz, Chloroform-d) δ 8.19 (d, J = 8.8
Hz, 1H), 7.91 – 7.81 (m, 4H), 7.64 (d, J = 2.1 Hz, 1H);
19
F NMR (470 MHz, Chloroform-d) δ -73.6 , -76.3 ;
13
C
NMR (126 MHz, Chloroform-d) δ 182.2 (q,
2
J C-F = 38.6
Hz), 181.1 (q,
2
J C-F = 37.3 Hz), 144.3 , 140.6 , 137.1 , 135.6 , 131.6 (q,
4
J C-F = 2.6 Hz), 131.3 ,
131.0 , 129.3 , 128.4 , 126.1 , 124.6 , 123.8 ,115.9 (q,
1
J C-F = 289.7Hz) 115.7(q,
1
J C-F, J =290
Hz); HRMS (ESI, m/z) for (C16H7N2O3F6Br2):calculated 546.8728 (neutral mass); found
546.8724 (M
•+
)

(Z)-1,2-bis(4-methoxy-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5e):
A: 4e was irradiated 4 hours following procedure A. Percentage Conversion: 2%
B: 4e was irradiated 4 hours following procedure B. Percentage Conversion: 4%
Appearance: bright yellow crystals
N
N
O
O F
3
C
CF
3
O Br
Br
73

1
H NMR (500 MHz, Chloroform-d) δ 8.25 (d, J = 8.7
Hz, 1H), 8.21 (d, J = 9.2, 1H), 7.19 – 7.11 (m, 3H),
6.90 (d, J = 2.8 Hz, 1H), 3.93 (s, 3H), 3.92 (s, 3H);
19
F NMR (470 MHz, Chloroform-d) δ -74.4 , -76.6 ;
13
C NMR (126 MHz, Chloroform-d) δ 183.5 ( q,
2
J C-F = 38.1 Hz )183.2 ( q,
2
J C-F = 37.2Hz),
162.9 , 160.3 , 138.5 , 134.7 , 131.3 , 131.2 , 127.1 , 124.6 , 117.8 , 117.1 , 116.1 (q,
1
J C-F =
291.6Hz), 116.0(q,
1
J C-F = 293.2Hz),113.9 ,113.0 , 56.4, 56.1; HRMS (ESI, m/z) for
(C
18
H
12
F
6
N
2
O5): calculated 451.0729 (M+H)
•+
found 451.0738 (M+H)
•+

(Z)-1,2-bis(4,5-dimethoxy-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5f)
A: 4f was irradiated 3.5 hours following procedure A. Percentage Conversion: 50.2%
Appearance: bright orange crystals.
The reaction mixture is concentrated so there was about 5-10 mL of isopropanol left. The
azoxybenzene recrystallized after 2 days.

1
H NMR (600 MHz, Chloroform-d) δ 7.82 (s, 1H),
7.79 (s, 1H), 7.27 (s, 1H), 6.88 (s, 1H), 4.03 (s, 3H),
4.00 (s, 3H), 3.98 (s, 6H);
19
F NMR (470 MHz,
Chloroform-d) δ -73.0, -76.2;
13
C NMR (151 MHz,
Chloroform-d) δ 183.4 (q,
2
J C-F = 37.4 Hz), 181.7
(q,
2
J C-F = 35.8 Hz),153.2, 152.6, 151.6, 149.3, 139.8, 138.0, 122.2, 121.2, 116.3 (q,
1
J C-F =
N
N
O
O F
3
C
CF
3
O MeO
OMe
N
N
O
O F
3
C
CF
3
O MeO
OMe
OMe
OMe
74

291.6 Hz) 116.1 (q,
1
J C-F = 290.4 Hz) 111.6, 109.7, 106.6, 105.6, 56.8, 56.7, 56.5, 56.5; HRMS
(ESI, m/z) for (C20H17N2O7F6): Calculated 511.0940 (M+H)
•+
;found 511.0954 (M+H)
•+

(Z)-1,2-bis(5-methoxy-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5g):
A: 4g was irradiated 4 hours following procedure A. Percentage Conversion: 16 %
Appearance: bright orange crystals.
1
H NMR (399 MHz, Chloroform-d) δ 7.97 (dd, J = 8.9, 1.7
Hz, 1H), 7.85 (d, J = 2.5 Hz, 1H), 7.62 (d, J = 8.7 Hz, 1H),
7.20 (dd, J = 8.6, 2.5 Hz, 1H), 7.04 (d, J = 2.5 Hz, 1H), 6.98
(dd, J = 8.9, 2.6 Hz, 1H), 4.00 (s, 3H), 3.95 (s, 3H);
19
F NMR
(470 MHz, Chloroform-d) δ -71.6, -74.8;
13
C NMR (126
MHz, Chloroform-d) δ 181.7 (q,
2
J C-F = 36.9 Hz), 178.7 (q,
2
J C-F = 35.2 Hz).

165.2, 163.6, 148.6,
147.4, 132.9, 132.9, 130.8, 130.8, 119.8, 118.0, 117.0, 116.5 (q,
1
J C-F = 292.0 Hz), 116.1 (q,
1
J C-
F = 290.9 Hz) 113.8, 109.7, 108.6, 56.4, 56.1; HRMS (ESI, m/z) for (C
18
H
11
F
6
N2O
5
): Calculated
449.0572[M-H]
-
found 449.0584[M-H]
-

(Z)-1,2-bis(2-(2,2,2-trifluoroacetyl)naphthalen-1-yl)diazene 1-oxide (5h):
A: 4h was irradiated 2 hours following procedure A. Percentage Conversion: 23%
B: 4h was irradiated 7 hours following procedure A. Percentage Conversion: 4%
Appearance: orange crystals
N
N
O
O F
3
C
CF
3
O
OMe
OMe
75

1
H NMR (500 MHz, Chloroform-d) δ 8.67 (d, J = 8.3 Hz,
1H),8.23 – 8.19 (m, 2H), 8.04 (d, J = 8.7 Hz, 2H), 7.96 (d, J =
8.3 Hz, 1H), 7.85 – 7.76 (m, 4H), 7.68 (t, J = 7.5 Hz, 1H), 7.58
(t, J = 7.3 Hz, 1H);
19
F NMR (470 MHz, Chloroform-d) δ -
72.34, -73.78 .;
13
C NMR (126 MHz, Chloroform-d) δ 182.0
(q,
2
J C-F =36.1Hz ), 181.2 (q,
2
J C-F = 37.2Hz ), 145.1 , 138.0 , 136.5 , 135.9 , 132.2 , 130.2 ,
130.1 , 129.8 , 129.3 , 128.4 , 128.4 , 128.3 , 128.2 , 126.3 , 124.7 , 124.6 , 124.2 , 122.7 (q, J C-F
= 2.5 Hz), 122.5 , 121.5 (q, J C-F = 2.7 Hz), 116.6 (q,
1
J C-F = 292.2 Hz), 116.0 (q,
1
J C-F = 289.6
Hz); HRMS (ESI, m/z) for (C24H13N2O3F6):calculated 491.0830 (neutral mass); found
491.0829(M
•+
)

Spectral data of benzisoxazolines
3-hydroxy-3-(trifluoromethyl)benzo[c]isoxazol-5(3H)-one (6e): It was synthesized using the
general procedure by irradiating 4e for 4.5 hours and leaving it undisturbed for 5 days. Appearance:
light yellow crystals, yield 37 %

1
H NMR (500 MHz, DMSO-d6) δ 10.05 (s, 1H), 7.86 (d, J = 9.9 Hz,
1H), 6.91 (d, J = 1.5 Hz, 1H), 6.68 (dd, J = 10.0, 1.6 Hz, 1H);
19
F NMR
(470 MHz, DMSO-d6) δ -84.6;
13
C NMR (126 MHz, DMSO-d6) δ 185.0, 152.3, 144.2, 133.1,
128.1, 120.9 (q,
1
J C-F = 285.1 Hz) 103.2 (q,
2
J C-F = 34.8Hz); HRMS (EI, m/z) for (C8H4NO3F3):
calculated 219.01433 (neutral mass); found 219.0401(M
•+
)
N
N
O
O F
3
C
CF
3
O
O
N
O
CF
3
OH
76

3-hydroxy-6-methoxy-3-(trifluoromethyl)benzo[c]isoxazol-5(3H)-one (6f): It was synthesized
using the general procedure by irradiating 4f for 4 hours and leaving it undisturbed for 2 days. It
formed light yellow crystals yield 12 %
1
H NMR (500 MHz, DMSO-d6) δ 9.89 (s, 1H), 7.01 (s, 1H), 6.91
(s, 1H), 3.84 (s, 3H);
19
F NMR (470 MHz, DMSO-d6) δ -84.7.
13
C
NMR (126 MHz, DMSO-d6) δ 178.5, 154.6, 152.8, 144.0, 126.8,
121.1 (q,
1
J C-F = 285.3 Hz).102.3 (q,
2
J C-F = 34.6 Hz), 98.4, 56.4; HRMS (ESI, m/z) for
(C
9
H
5
F
3
NO
4
): calculated 248.0170 [M-H]
-
found 248.0194[M-H]
-

6-(difluoromethoxy)-3-hydroxy-3-(trifluoromethyl)benzo[c]isoxazol-5(3H)-one (6i): It was
synthesized using the general procedure by irradiating 4i for 5 hours 15 mins and leaving it
undisturbed for 7 days. After removing the DMSO completely the residue was dissolved in diethyl
ether and allowed to stand for a few minutes. A small amount precipitate is formed (precipitate is
small amount of the nitroketone). The solution was decanted into another centrifuge tube. The
ether was evaporated, and chloroform was added. It recrystallizes to form the final product.
Appearance: light yellow crystals; yield 22%.
1
H NMR (500 MHz, DMSO-d6) δ 10.12 (s, 1H), 7.55 (s, 1H), 7.52
– 7.16 (m, 1H), 7.06 (s, 1H);
19
F NMR (470 MHz, DMSO-d6) δ -
84.4, -86.3 – -87.7 (m);
13
C NMR (126 MHz, DMSO-d6) δ 177.2,
152.1, 147.4, 143.5, 127.3, 120.9 (q,
1
J C-F = 285.3 Hz) 115.6 (t,
1
J C-F = 259.9 Hz),108.6, 103.3
(q,
2
J C-F = 34.9 Hz); HRMS (ESI, m/z) for (C9H3F5NO4): calculated 283.9982 [M-H]
-
found
284.0017[M-H]
-

Spectral data of trifluoroacetyl nitsoarenes and their hydrates
O
N
O
CF
3
OH
HF
2
CO
O
N
O
CF
3
OH
MeO
77

1-(2-nitrosophenyl)-2,2,2-trifluoroethan-1-one (7a): The general
procedure was followed irradiating 1a for 4 hours. 0.5mmol of the alcohol
4a was dissolved in acetonitrile. Yield (
19
F NMR) 0.30mmol 60%:
1
H
NMR (500 MHz, Chloroform-d) δ 8.79 (d, J = 7.9 Hz, 1H), 8.01 (t, J = 7.7 Hz, 1H), 7.89 (t, J =
7.5 Hz, 1H), 7.46 (d, J = 7.5 Hz, 1H);
19
F NMR (470 MHz, Chloroform-d) δ -76.6;
13
C NMR (126
MHz, Chloroform-d) δ 186.6 (q,
2
J C-F = 38.2 Hz),163.1, 136.3, 133.6, 129.7, 127.9, 121.9, 115.3
(q,
1
J C-F = 290.6 Hz)
2,2,2-trifluoro-1-(5-fluoro-2-nitrosophenyl)ethenone (7b): The general
procedure was followed irradiating 4b for 4 hours. Yield (
19
F NMR)
(27%)
1
H NMR (500 MHz, Chloroform-d) δ, 8.90 (dd, J = 8.7, 5.1 Hz, 1H), 7.15 (ddd, J = 7.3, 2.6, 0.8
Hz, 1H), 7.15 (dd, J = 7.3, 2.6 Hz, 1H).

There is a triplet of doublets that appears 7.64-7.68ppm
however since it overlaps with the starting material exact measurement could not be made;
19
F
NMR (470 MHz, Chloroform-d 3) δ -77.2, -96.46--96.50(m).

1-(4-chloro-2-nitrosophenyl)-2,2,2-trifluoroethane-1,1-diol (8c): The general procedure was
followed irradiating 4c for 4 hours. Yield (36%)
1
H NMR (500 MHz, DMSO-d6) δ 8.38 (s, 2H), 8.00 (d, J = 2.3 Hz, 1H),
7.61 (dd, J = 8.5, 2.3 Hz, 1H), 6.05 (d, J = 8.5 Hz, 1H);
19
F NMR (470
MHz, DMSO-d6) δ -84.3;
13
C NMR (126 MHz, DMSO-d6) δ 162.3,
139.8, 139.6, 134.5, 130.3, 130.1, 123.4 (q,
1
J C-F = 289.3 Hz), 109.5, 93.6 (q,
2
J C-F = 33.3 Hz)

NO
O
CF
3
NO
OH
CF
3
OH
Cl
NO
O
CF
3
F
78

1-(5-chloro-2-nitrosophenyl)-2,2,2-trifluoroethanone (7c): The hydrate
of the nitroso arene (8c) was left in chloroform and capped. It eventually
gets converted to 5b over 2-3 days. While 4b is insoluble in chloroform 5b
is soluble.
1
H NMR (500 MHz, Chloroform-d) δ 8.75 (d, J = 8.4, 1H), 7.97 (dd, J = 8.2, 2.1 Hz,
1H), 7.42 (d, J = 2.0 Hz, 1H);
19
F NMR (470 MHz, Chloroform-d) δ -76.6;
13
C NMR (126 MHz,
Chloroform-d) δ 185.2 (q,
2
J C-F = 38.9 Hz),161.1, 144.0, 133.5, 130.7, 128.3, 123.4, 115.2 (q,
1
J
C-F = 290.4 Hz).

2,2,2-trifluoro-1-(5-bromo-2-nitrosophenyl)ethenone (8d):

The general procedure was
followed irradiating 4d for 4 hours. The crystals of its dimer were grown in DMSO using the
lyophilizer. Yield 50%
1
H NMR (600 MHz, DMSO-d6) δ 8.36 (s, 2H), 8.15 (d, J = 2.1 Hz,
1H), 7.74 (dd, J = 8.5, 2.2 Hz, 1H), 5.93 (d, J = 8.5 Hz, 1H):
19
F NMR
(470 MHz, DMSO-d6) δ -84.29;
13
C NMR (151 MHz, DMSO-d6) δ
162.6, 139.6, 133.4, 133.0, 123.4 (q,
1
J C-F = 289.0 Hz), 109.4, 93.6 (q,
2
J C-F = 33.1 Hz).

2,2,2-trifluoro-1-(5-methoxy-2-nitrosophenyl)ethenone (7e): The
general procedure was followed irradiating 4e for 3 hours.. Yield (
19
F
NMR): (94%)
1
H NMR (600 MHz, DMSO-d6) δ 9.33 (d, J = 8.9 Hz, 1H), 7.66 (dd, J =
8.9, 2.6 Hz, 1H), 7.28 (d, J = 2.6 Hz, 1H), 4.05 (s, 4H);
19
F NMR (564 MHz, DMSO-d6) δ -78.4;

NO
O
CF
3
Cl
NO
OH
CF
3
OH
Br
NO
O
CF
3
MeO
79

13
C NMR (151 MHz, DMSO-d6) δ 184.8 (q,
3
J C-F = 37.3 Hz),167.7, 161.1, 138.7, 122.1,121.0 (q,
1
J C-F = 285.0 Hz)117.3, 115.2, 57.5

2.9. References
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[2] Cameron, J. F.; Fréchet, J. M. J. Photogeneration of Organic Bases from O-Nitrobenzyl-
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[5] Watanabe, S.; Sueyoshi T.; Ichihara, M.; Uehara, C.; Iwamura, M. Reductive ring opening
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[7] Mathew,T.; Ajayaghosh, A.; Das, S. Kamat, P.V. George, M.V. A new photodegradable
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studies. Photochem. Photobiol. A. Chem. 1993, 71, 181-189.
80

[8] Chaulk, S. G.; MacMillan, A. M. Caged RNA: Photo-control of a ribozyme reaction,
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[9] Albert, T.J.; Norton, J.; Ott, M.; Richmond, T. Light-directed 5’->3’ synthesis of complex
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of dendrimers with α-carboxy-2-nitrobenzyl caged compounds at their periphery, J. Am.
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88

2.10 Appendix
2,2,2-trifluoro-1-(2-nitrophenyl)ethanol (4a)

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
Fluorine_01

-78.00
-77.98
-78.15 -78.05 -77.95 -77.85
f1 (ppm)
-78.00
-77.98
CF
3
OH
NO
2
UV-Vis Spectrum
19
F NMR Spectrum
89

-1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
1.10
1.04
1.05
1.07
1.05
1.00
2.92
2.94
6.14
6.16
6.17
6.17
6.17
6.19
6.20
7.57
7.57
7.58
7.59
7.59
7.59
7.60
7.61
7.71
7.72
7.72
7.73
7.73
7.73
7.74
7.74
7.75
7.75
7.75
7.76
7.95
7.97
8.02
8.02
8.02
8.02
8.04
8.04
8.04
8.04
7.6 7.7 7.8 7.9 8.0 8.1
f1 (ppm)
1.05
1.07
1.05
1.00
7.57
7.58
7.59
7.59
7.59
7.60
7.61
7.72
7.73
7.73
7.74
7.74
7.95
7.97
8.02
8.02
8.02
8.02
8.04
8.04
8.04
8.04
-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
66.65
66.91
67.17
67.43
120.59
122.84
125.09
125.15
127.34
128.91
129.56
129.57
129.58
130.39
133.75
148.71
120 125 130 135 140 145 150
f1 (ppm)
122.84
125.09
125.15
127.34
128.91
129.56
129.57
129.58
130.39
133.75
148.71
1
H NMR Spectrum
13
C NMR Spectrum
90

2,2,2-trifluoro-1-(5-fluoro-2-nitrophenyl)ethanol (4b)

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
-78.11
-78.09
-78.20 -78.10 -78.00
f1 (ppm)
-78.11
-78.09
19
F N M R ( 470 M H z , C D C l 3 )
CF
3
OH
NO
2
F
UV-Vis Spectrum
19
F NMR Spectrum
91

-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
1.11
1.07
1.85
1.02
1.00
3.03
3.04
6.27
6.28
6.29
6.30
6.32
7.23
7.24
7.25
7.25
7.26
7.27
7.27
7.67
7.67
7.69
7.69
8.12
8.13
8.14
8.15
7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 8.0 8.1 8.2
f1 (ppm)
1.85
1.02
1.00
7.23
7.24
7.25
7.25
7.26
7.27
7.27
7.67
7.67
7.69
7.69
8.12
8.13
8.14
8.15 1
H N M R ( 500 M H z , C D C l 3 )
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210
f1 (ppm)
66.39
66.65
66.91
67.17
116.96
117.17
117.31
117.49
120.32
122.57
124.82
127.07
128.15
128.22
132.64
132.71
144.49
164.20
166.25
62 63 64 65 66 67 68 69 70
f1 (ppm)
66.39
66.65
66.91
67.17
13
C N M R ( 126 M H z , C D C l 3 ) .
1
H NMR Spectrum
13
C NMR Spectrum
92

2,2,2-trifluoro-1-(5-chloro-2-nitrophenyl)ethanol (4c)

CF
3
OH
NO
2
Cl
UV-Vis Spectrum
19
F NMR Spectrum
93

-0.5 0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 10.5 11.5 12.5
f1 (ppm)
1.03
1.13
1.35
1.71
1.66
2.96
2.97
6.24
6.25
6.26
6.27
6.29
7.55
7.55
7.57
7.57
7.97
7.97
8.02
8.04
8.04
1
H N M R ( 500 M H z , c dc l 3 )
-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
66.36
66.62
66.88
67.14
120.31
122.56
124.81
126.72
127.06
129.87
130.54
130.89
140.69
146.66 115 120 125 130
f1 (ppm)
120.31
122.56
124.81
126.72
127.06
129.87
130.54
130.89
13
C N M R ( 126 M H z , c dc l 3 )
1
H NMR Spectrum
13
C NMR Spectrum
94

2,2,2-trifluoro-1-(5-bromo-2-nitrophenyl)ethanol (4d)

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
-78.05
-78.03
-78.4 -78.2 -78.0 -77.8 -77.6
f1 (ppm)
-78.05
-78.03
19
F N M R ( 376 M H z , c dc l 3 )
UV-Vis Spectrum
19
F NMR Spectrum
CF
3
OH
NO
2
Br
95

- 0 . 5 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 4 . 0 4 . 5 5 . 0 5 . 5 6 . 0 6 . 5 7 . 0 7 . 5 8 . 0 8 . 5 9 . 0 9 . 5 1 0 . 0 1 0 . 5 1 1 . 0 1 1 . 5 1 2 . 0
f 1 ( p p m )
1 . 0 7
1 . 0 4
1 . 0 4
1 . 0 2
1 . 0 0
2 . 5 8
2 . 5 9
5 . 8 8
5 . 9 0
5 . 9 1
5 . 9 2
5 . 9 4
7 . 3 8
7 . 3 8
7 . 4 0
7 . 4 0
7 . 5 9
7 . 6 1
7 . 7 9
7 . 7 9
1
H N M R ( 400 M H z , c dc l 3 )
-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220
f1 (ppm)
66.11
66.44
66.76
67.09
119.49
122.31
125.12
126.65
127.94
129.01
130.86
132.82
133.57
147.17
13
C N M R ( 100 M H z , c d c l 3 )
1
H NMR Spectrum
13
C NMR Spectrum
96

2,2,2-trifluoro-1-(5-methoxy-2-nitrophenyl)ethanol (4e)

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
-77.81
-77.79
-77.85 -77.75
f1 (ppm)
-77.81
-77.79
19
F N M R ( 470 M H z , C D C l 3 ) .
CF
3
OH
NO
2
MeO
UV-Vis Spectrum
19
F NMR Spectrum
97

-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
1.01
3.26
1.02
1.03
1.03
1.00
3.02
3.03
3.94
6.33
6.34
6.35
6.36
6.37
6.99
6.99
7.00
7.01
7.41
8.12
8.14
6.9 7.1 7.3 7.5 7.7 7.9 8.1 8.3
f1 (ppm)
1.03
1.03
1.00
6.99
6.99
7.00
7.01
7.41
8.12
8.14
1
H N M R ( 500 M H z , C D C l 3 )
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190
f1 (ppm)
56.22
66.77
67.02
67.28
67.54
114.60
114.97
120.60
122.85
125.10
127.35
128.12
132.08
141.41
163.78
C F C l 3
116 118 120 122 124 126 128 130 132
f1 (ppm)
120.60
122.85
125.10
127.35
128.12
132.08
13
C N M R ( 126 M H z , C D C l 3 ) .
1
H NMR Spectrum
13
C NMR Spectrum
98

19
F NMR Spectrum
1-(4,5-dimethoxy-2-nitrophenyl)-2,2,2-trifluoroethan-1-ol (4f)

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
-77.93
-77.92
-78.2 -78.1 -78.0 -77.9 -77.8 -77.7
f1 (ppm)
-77.93
-77.92
CF
3
OH
NO
2
MeO
MeO
UV-Vis Spectrum
99

-1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0
f1 (ppm)
1.05
3.70
3.62
1.19
1.15
1.00
2.88
2.88
2.90
2.90
3.97
4.01
6.30
6.32
6.33
6.35
6.36
7.34
7.65
1
H N M R ( 400 M H z , c dc l 3 )
-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
56.60
56.72
66.62
66.84
67.05
67.27
108.32
110.53
121.28
123.15
123.64
125.03
126.90
141.24
149.42
153.50
13
C N M R ( 151 M H z , c d c l 3 )
1
H NMR Spectrum
13
C NMR Spectrum
100

2,2,2-trifluoro-1-(4-methoxy-2-nitrophenyl)ethanol (4g)

- 2 0 0 - 1 9 0 - 1 8 0 - 1 7 0 - 1 6 0 - 1 5 0 - 1 4 0 - 1 3 0 - 1 2 0 - 1 1 0 - 1 0 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0 3 0
f 1 ( p p m )
- 7 8 . 1 6
- 7 8 . 1 5
- 7 8 . 3 5 - 7 8 . 2 5 - 7 8 . 1 5 - 7 8 . 0 5 - 7 7 . 9 5
f 1 ( p p m )
- 7 8 . 1 6
- 7 8 . 1 5
CF
3
OH
NO
2
MeO
UV-Vis Spectrum
19
F NMR Spectrum
101

-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
0.95
2.87
0.96
0.89
0.93
1.00
2.95
3.90
6.01
6.03
6.04
6.06
7.21
7.22
7.23
7.24
7.51
7.52
7.82
7.84
7.0 7.2 7.4 7.6 7.8 8.0
f1 (ppm)
0
500
1000
1500
0.89
0.93
1.00
7.21
7.22
7.23
7.24
7.51
7.52
7.82
7.84
- 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 10 0 110 12 0 13 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
5 6 . 1 3
6 6 . 5 2
6 6 . 7 8
6 7 . 0 5
6 7 . 3 1
1 1 0 . 1 5
1 1 9 . 8 3
1 2 0 . 6 9
1 2 0 . 7 2
1 2 2 . 9 7
1 2 5 . 2 2
1 2 7 . 4 7
1 3 0 . 6 9
1 4 9 . 5 4
1 6 0 . 6 7
1 2 1 1 2 2 1 2 3 1 2 4 1 2 5 1 2 6 1 2 7 1 2 8
f 1 ( p p m )
0
5 0
1 0 0
1 5 0
1 2 0 . 6 9
1 2 0 . 7 2
1 2 2 . 9 7
1 2 5 . 2 2
1 2 7 . 4 7
6 6 6 7 6 8 6 9
f 1 ( p p m )
0
1 0 0 0
2 0 0 0
6 6 . 5 2
6 6 . 7 8
6 7 . 0 5
6 7 . 3 1
13
C N M R ( 12 6 M H z , c d c l 3 ) δ
13
C NMR Spectrum
1
H NMR Spectrum
102

2,2,2-trifluoro-1-(1-nitronaphthalen-2-yl)ethanol (4h)

CF
3
OH
NO
2 UV-Vis Spectrum
19
F NMR Spectrum
-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
-77.71
-77.70
-77.9 -77.7
f1 (ppm)
-77.71
-77.70
1 9
F N M R ( 47 0 M H z , C D C l 3 )
103

1
H NMR Spectrum

-2.0 -1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
f1 (ppm)
2.87
2.88
5.43
5.44
5.45
5.46
5.48
7.65
7.66
7.67
7.67
7.67
7.68
7.69
7.69
7.69
7.70
7.71
7.78
7.78
7.78
7.79
7.80
7.85
7.87
7.95
7.95
7.96
7.97
7.97
8.07
8.09
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220
f1 (ppm)
67.62
67.89
68.16
68.43
120.39
122.35
122.64
123.52
123.64
124.24
124.89
127.14
128.27
128.65
129.33
131.55
134.34
148.18
C F C l 3
13
C N M R ( 126 M H z , C D C l 3 )
13
C NMR Spectrum
104

1-(4-(difluoromethoxy)-5-methoxy-2-nitrophenyl)-2,2,2-trifluoroethan-1-ol (4i)

- 2 0 0 - 1 9 0 - 1 8 0 - 1 7 0 - 1 6 0 - 1 5 0 - 1 4 0 - 1 3 0 - 1 2 0 - 1 1 0 - 1 0 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0 3 0
f 1 ( p p m )
- 8 3 . 3 4
- 8 3 . 1 8
- 8 2 . 9 9
- 8 2 . 8 3
- 8 2 . 8 1
- 8 2 . 6 6
- 8 2 . 4 7
- 8 2 . 3 1
- 7 7 . 9 7
- 7 7 . 9 6
- 8 5 - 8 4 - 8 3 - 8 2 - 8 1 - 8 0
f 1 ( p p m )
0
5 0 0 0
1 0 0 0 0
1 5 0 0 0
- 8 3 . 3 4
- 8 3 . 1 8
- 8 2 . 9 9
- 8 2 . 8 3
- 8 2 . 8 1
- 8 2 . 6 6
- 8 2 . 4 7
- 8 2 . 3 1
1 9
F N M R ( 47 0 M H z , c d c l 3 )
CF
3
OH
NO
2
MeO
HF
2
CO
19
F NMR Spectrum
105

- 2 - 1 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4
f 1 ( p p m )
1 . 1 5
3 . 6 3
1 . 2 1
1 . 3 2
1 . 2 0
1 . 0 0
3 . 0 6
3 . 0 7
4 . 0 3
6 . 3 7
6 . 3 9
6 . 4 0
6 . 4 1
6 . 4 2
6 . 4 9
6 . 6 4
6 . 7 8
7 . 2 6
7 . 5 0
8 . 0 0
- 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 10 0 11 0 12 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
5 6 . 9 6
6 6 . 3 5
6 6 . 6 2
6 6 . 8 8
6 7 . 1 4
1 1 2 . 4 1
1 1 3 . 3 4
1 1 5 . 4 4
1 1 7 . 5 4
1 1 9 . 7 5
1 2 0 . 4 6
1 2 2 . 7 1
1 2 4 . 9 6
1 2 7 . 2 1
1 2 9 . 1 4
1 3 9 . 6 8
1 4 0 . 6 5
1 5 5 . 5 9
13
C N M R ( 12 6 M H z , c dc l 3 )
1
H NMR Spectrum
13
C NMR Spectrum
106

19
F NMR Spectrum
(Z)-1,2-bis(2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5a)

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
1.04
1.00
-76.38
-73.14
19
F N M R ( 470 M H z , C D C l 3 )
-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
1.99
4.09
1.00
1.00
7.53
7.54
7.54
7.55
7.56
7.75
7.76
7.77
7.77
7.78
7.79
7.80
7.86
7.88
8.35
8.36
8.37
8.38
8.38
8.39
7.5 7.6 7.7 7.8 7.9 8.0 8.1 8.2 8.3 8.4 8.5 8.6
f1 (ppm)
1.99
4.09
1.00
1.00
7.53
7.54
7.54
7.55
7.75
7.76
7.77
7.77
7.78
7.79
7.80
7.86
7.88
8.35
8.36
8.37
8.38
8.38
8.39
N
N
O
O F
3
C
CF
3
O
1
H NMR Spectrum
107

-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
f1 (ppm)
112.48
112.69
114.79
115.03
117.10
117.35
119.41
119.67
123.39
124.45
126.82
128.36
129.02
129.04
129.06
129.08
129.28
129.56
132.56
133.12
134.42
142.66
145.54
181.16
181.45
181.73
183.31
183.61
183.91
184.21
176 178 180 182 184 186 188 190 192
f1 (ppm)
181.16
181.45
181.73
183.31
183.61
183.91
184.21
110 112 114 116 118 120
f1 (ppm)
112.48
112.69
114.79
115.03
117.10
117.35
119.41
119.67
1 3
C N M R ( 12 6 M H z , C D C l 3 )
13
C NMR Spectrum
13
C NMR Spectrum
108

(Z)-1,2-bis(4-fluoro-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5b)

F
-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
-107.26
-107.25
-107.25
-107.24
-107.23
-107.22
-103.20
-103.19
-103.18
-103.18
-103.17
-103.16
-76.38
-73.72
-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
0.92
2.02
0.96
1.00
1.00
7.21
7.21
7.22
7.23
7.41
7.41
7.42
7.43
7.43
7.44
7.44
7.45
7.45
7.45
7.46
7.47
7.49
7.50
7.51
7.98
7.99
8.00
8.01
8.34
8.35
8.36
8.37
7.0 7.2 7.4 7.6 7.8 8.0 8.2 8.4 8.6
f1 (ppm)
0.92
2.02
0.96
1.00
1.00
7.21
7.21
7.22
7.23
7.42
7.43
7.43
7.44
7.44
7.45
7.45
7.45
7.49
7.50
7.51
7.98
7.99
8.00
8.01
8.34
8.35
8.36
8.37
1
H N M R ( 5 00 M H z , C D C l 3 )
N
N
O
O F
3
C
CF
3
O F
F
19
F NMR Spectrum
1
H NMR Spectrum
109

13
C NMR Spectrum

-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
1 3
C N M R ( 126 M H z , C D C l 3 )
100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
f1 (ppm)
114.60
114.77
115.76
115.96
116.01
116.03
116.05
116.07
116.21
116.24
116.26
116.28
116.91
117.08
119.31
119.50
120.93
121.11
125.82
125.89
127.18
127.25
129.72
129.78
131.86
131.92
138.05
138.08
141.40
160.87
162.91
163.76
165.83
180.59
180.87
180.89
181.17
181.47
181.63
181.93
181.95
182.25
182.55
178 179 180 181 182 183 184
f1 (ppm)
180.59
180.87
180.89
181.17
181.47
181.63
181.93
181.95
182.25
182.55
110 112 114 116 118 120 122
f1 (ppm)
112.29
114.60
114.77
115.76
115.96
116.01
116.03
116.05
116.07
116.21
116.24
116.26
116.28
116.91
117.08
119.22
119.31
119.40
119.50
120.93
121.11
13
C N M R ( 126 M H z , C D C l 3 )
13
C NMR Spectrum
110

(Z)-1,2-bis(4-chloro-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5c)

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
1.02
1.00
-76.35
-73.63
1 9
F N M R ( 47 0 M H z , C D C l 3 )
-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
0.93
2.02
0.99
1.04
1.00
7.26
7.48
7.49
7.70
7.71
7.72
7.72
7.76
7.90
7.92
8.26
8.28
7.4 7.5 7.6 7.7 7.8 7.9 8.0 8.1 8.2 8.3 8.4 8.5
f1 (ppm)
0.93
2.02
0.99
1.04
1.00
7.48
7.49
7.70
7.71
7.72
7.72
7.76
7.90
7.92
8.26
8.28
1
H N M R ( 50 0 M H z , C D C l 3 )
N
N
O
O F
3
C
CF
3
O Cl
Cl
19
F NMR Spectrum
1
H NMR Spectrum
111

-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
1 3
C N M R ( 126 M H z , C D C l 3 )
95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185 190
f1 (ppm)
112.26
112.42
114.57
114.73
116.88
117.05
119.19
119.37
124.59
126.12
128.40
128.71
128.74
128.76
128.78
129.23
130.97
132.52
134.05
135.89
140.13
140.22
143.69
180.69
180.99
181.28
181.58
181.80
182.11
182.42
182.72
177 178 179 180 181 182 183 184 185
f1 (ppm)
180.69
180.99
181.28
181.58
181.80
182.11
182.42
182.72
111 112 113 114 115 116 117 118 119 120
f1 (ppm)
112.26
112.42
114.57
114.73
116.88
117.05
119.19
119.37
13
C N M R ( 126 M H z , C D C l 3 )
13
C NMR Spectrum
13
C NMR Spectrum
112

19
F NMR Spectrum
(Z)-1,2-bis(4-bromo-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5d)

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
-76.34
-73.61
19
F N M R ( 470 M H z , C D C l 3 )
-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
0.89
4.08
1.00
7.26
7.63
7.64
7.82
7.82
7.82
7.83
7.84
7.84
7.86
7.86
7.86
7.87
7.87
7.87
7.88
7.88
7.88
7.88
7.88
7.89
7.89
7.90
7.90
7.90
7.90
7.90
7.90
8.18
8.20
7.5 7.6 7.7 7.8 7.9 8.0 8.1 8.2
f1 (ppm)
0.89
4.08
1.00
7.63
7.64
7.82
7.83
7.84
7.84
7.86
7.86
7.86
7.87
7.88
7.88
7.88
7.89
7.89
7.90
7.90
7.90
7.90
8.18
8.20
1
H N M R ( 5 00 M H z ,
C D C l 3 )
N
N
O
O F
3
C
CF
3
O Br
Br
1
H NMR Spectrum
113

13
C NMR Spectrum

-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
76.91 CDCl3
77.16 CDCl3
77.41 CDCl3
1 3
C N M R ( 126 M H z , C D C l 3 ) .
100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
f1 (ppm)
112.25
112.40
114.56
114.72
116.87
117.04
119.18
119.35
123.76
124.61
126.15
128.37
129.35
131.00
131.28
131.57
131.59
131.61
131.63
135.60
137.09
140.59
144.26
180.62
180.91
181.21
181.51
181.72
182.02
182.33
182.64
178 179 180 181 182 183 184
f1 (ppm)
180.62
180.91
181.21
181.51
181.72
182.02
182.33
182.64
108 110 112 114 116 118 120
f1 (ppm)
112.25
112.40
114.56
114.72
116.87
117.04
119.18
119.35
13
C N M R ( 126 M H z , C D C l 3 )
13
C NMR Spectrum
114

19
F NMR Spectrum
(Z)-1,2-bis(4-methoxy-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5e)

-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
1.03
1.00
-76.64
-74.43
19
F N M R ( 470 M H z , C D C l 3 )
-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
3.02
3.06
0.93
3.12
1.01
1.00
3.92
3.93
6.90
7.12
7.13
7.14
7.15
7.16
7.18
7.19
7.26
8.20
8.21
8.24
8.26
6.6 6.8 7.0 7.2 7.4 7.6 7.8 8.0 8.2 8.4
f1 (ppm)
0.93
3.12
1.01
1.00
6.90
7.12
7.13
7.14
7.15
7.16
7.18
7.19
7.26
8.20
8.21
8.24
8.26
3.85 3.90 3.95 4.00 4.05
f1 (ppm)
3.02
3.06
3.92
3.93
1
H N M R ( 5 00 M H z , C D C l 3 )
N
N
O
O F
3
C
CF
3
O MeO
OMe
1
H NMR Spectrum
115

-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
13
C N M R ( 126 M H z , C D C l 3 )
105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
f1 (ppm)
112.55
112.61
113.06
113.92
113.93
113.95
114.87
114.93
117.10
117.17
117.25
117.76
119.48
119.56
124.61
127.11
131.24
131.32
134.74
138.51
160.33
162.95
182.72
183.01
183.31
183.61
183.92
55 56 57 58
f1 (ppm)
56.11
56.40
181.5 182.5 183.5 184.5
f1 (ppm)
182.72
183.01
183.31
183.61
183.92
108 110 112 114 116 118 120
f1 (ppm)
112.55
112.61
113.06
113.92
113.93
113.95
114.87
114.93
117.10
117.17
117.25
117.76
119.48
119.56
13
C N M R ( 126 M H z , C D C l 3 ) .
13
C NMR Spectrum
13
C NMR Spectrum
116

(Z)-1,2-bis(4,5-dimethoxy-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5f)

- 2 0 0 - 1 9 0 - 1 8 0 - 1 7 0 - 1 6 0 - 15 0 - 1 4 0 - 13 0 - 12 0 - 1 10 - 1 0 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0 3 0
f 1 ( p p m )
1 . 1 0
1 . 0 0
- 7 6 . 1 6
- 7 2 . 9 6
-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
6.49
3.62
3.14
1.08
0.50
1.18
1.06
0.98
3.98
4.00
4.03
6.88
7.26
7.27
7.79
7.82
3.85 3.90 3.95 4.00 4.05 4.10
f1 (ppm)
6.49
3.62
3.14
3.98
4.00
4.03
6.6 6.8 7.0 7.2 7.4 7.6 7.8
f1 (ppm)
1.08
0.50
1.18
1.06
0.98
6.88
7.26
7.27
7.79
7.82
1
H N M R ( 6 00 M H z , c d c l 3 )
N
N
O
O F
3
C
CF
3
O MeO
OMe
OMe
OMe
19
F NMR Spectrum
1
H NMR Spectrum
117

(Z)-1,2-bis(5-methoxy-2-(2,2,2-trifluoroacetyl)phenyl)diazene 1-oxide (5g)

-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
56.48
56.51
56.73
56.85
105.58
106.65
109.74
111.59
113.22
113.43
115.15
115.36
117.07
117.29
119.00
119.22
121.22
122.22
138.07
139.82
149.30
151.57
152.61
153.24
181.30
181.54
181.78
182.02
183.07
183.32
183.57
183.82
181.0 182.0 183.0 184.0
f1 (ppm)
181.30
181.54
181.78
182.02
183.07
183.32
183.57
183.82
106 108 110 112 114 116 118 120 122
f1 (ppm)
105.58
106.65
109.74
111.59
113.22
113.43
115.15
115.36
117.07
117.29
119.00
119.22
121.22
122.22
13
C N M R ( 151 M H z , c d c l 3 )
-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
-74.76
-71.61
1 9
F N M R ( 4 70 M H z , c dc l 3 )
N
N
O
O F
3
C
CF
3
O
OMe
OMe
19
F NMR Spectrum
13
C NMR Spectrum
118

-1 0 1 2 3 4 5 6 7 8 9 10 11 12 13
f1 (ppm)
3.01
2.89
1.08
0.91
1.02
1.02
0.98
1.00
3.95
4.00
6.97
6.97
6.99
6.99
7.04
7.05
7.19
7.20
7.21
7.22
7.61
7.63
7.84
7.85
7.96
7.97
7.98
7.99
6.4 6.6 6.8 7.0 7.2 7.4 7.6 7.8 8.0 8.2 8.4
f1 (ppm)
1.08
0.91
1.02
1.02
0.98
1.00
6.97
6.97
6.99
6.99
7.04
7.05
7.19
7.20
7.21
7.22
7.61
7.63
7.84
7.85
7.96
7.97
7.98
7.99
1
H N M R ( 3 99 M H z , c d c l 3 )
-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
56.14
56.45
108.62
109.68
112.66
113.02
113.76
114.98
115.35
117.01
117.29
117.67
117.98
119.61
119.79
119.99
130.85
132.89
147.42
148.65
163.65
165.19
178.27
178.55
178.83
179.11
181.25
181.54
181.84
182.13
1 3
C N M R ( 1 26 M H z , c dc l 3 )
1
H NMR Spectrum
13
C NMR Spectrum
119

(Z)-1,2-bis(2-(2,2,2-trifluoroacetyl)naphthalen-1-yl)diazene 1-oxide (5h)

105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
f1 (ppm)
108.62
109.68
112.66
113.02
113.76
114.98
115.35
117.01
117.29
117.67
117.98
119.61
119.79
119.99
130.85
132.89
147.42
148.65
163.65
165.19
178.27
178.55
178.83
179.11
181.25
181.54
181.84
182.13
54.5 55.5 56.5 57.5
f1 (ppm)
0
500
1000
1500 56.14
56.45
13
C N M R ( 126 M H z , c dc l 3 )
-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
1.06
1.00
-73.78
-72.34
1 9
F N M R ( 47 0 M H z , C D C l 3 )
N
N
O
O F
3
C
CF
3
O
19
F NMR Spectrum
13
C NMR Spectrum
120

-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
f1 (ppm)
1.06
1.01
4.06
1.04
2.01
2.04
1.00
7.26
7.26
7.56
7.57
7.58
7.59
7.67
7.68
7.70
7.77
7.77
7.77
7.78
7.78
7.78
7.79
7.80
7.80
7.80
7.81
7.81
7.81
7.81
7.82
7.82
7.83
7.83
7.83
7.84
7.84
7.84
7.85
7.95
7.97
8.03
8.05
8.19
8.21
8.22
8.22
8.23
8.66
8.68
7.5 8.0 8.5
f1 (ppm)
1.06
1.01
4.06
1.04
2.01
2.04
1.00
7.58
7.68
7.78
7.78
7.80
7.80
7.81
7.82
7.82
7.83
7.84
7.95
7.97
8.03
8.05
8.19
8.21
8.22
8.23
8.66
8.68
-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
1 3
C N M R ( 126 M H z , C D C l 3 )
1
H NMR Spectrum
13
C NMR Spectrum
121

3-hydroxy-3-(trifluoromethyl)benzo[c]isoxazol-5(3H)-one (6e)

105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
f1 (ppm)
CARBON_01
naph NNO
112.58
113.17
114.90
115.49
117.21
117.81
119.53
120.13
121.44
121.46
121.48
121.50
122.50
122.66
122.68
122.70
122.72
124.23
124.63
124.68
126.30
128.20
128.27
128.37
128.39
129.32
129.80
130.08
130.21
132.16
135.95
136.55
138.00
145.10
180.73
181.03
181.32
181.53
181.62
181.81
182.10
182.39
179 180 181 182 183 184
f1 (ppm)
0
100
200
300
400
500
600
700
180.73
181.03
181.32
181.53
181.62
181.81
182.10
182.39
110 112 114 116 118 120
f1 (ppm)
0
100
200
300
400
500
600
700
112.58
113.17
114.90
115.49
117.21
117.81
119.53
120.13
-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
-84.59
O
N
O
CF
3
OH
19
F NMR Spectrum
13
C NMR Spectrum
122

- 2 - 1 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 13 1 4
f 1 ( p p m )
1 . 0 2
0 . 9 0
1 . 0 0
1 . 2 1
6 . 6 6
6 . 6 7
6 . 6 7
6 . 6 7
6 . 6 8
6 . 6 9
6 . 6 9
6 . 6 9
6 . 9 1
6 . 9 1
7 . 8 5
7 . 8 7
1 0 . 0 5
1
H N M R ( 500 M H z , dm s o )
- 10 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 11 0 12 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
1 0 2 . 8 3
1 0 3 . 1 1
1 0 3 . 3 8
1 0 3 . 6 6
1 1 7 . 5 5
1 1 9 . 8 2
1 2 2 . 0 9
1 2 4 . 3 6
1 2 8 . 1 2
1 3 3 . 1 5
1 4 4 . 2 4
1 5 2 . 2 6
1 8 5 . 0 2
13
C N M R ( 126 M H z , dm s o)
1
H NMR Spectrum
13
C NMR Spectrum
123

3-hydroxy-6-methoxy-3-(trifluoromethyl)benzo[c]isoxazol-5(3H)-one (6f)

- 2 0 0 - 1 9 0 - 1 8 0 - 1 7 0 - 1 6 0 - 1 5 0 - 1 4 0 - 1 3 0 - 1 2 0 - 1 1 0 - 1 0 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0
f 1 ( p p m )
- 8 4 . 6 9
- 6 3 . 7 2
1 9
F N M R ( 4 70 M H z , dm s o)
- 2 - 1 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4
f 1 ( p p m )
2 . 9 8
0 . 8 9
1 . 0 0
0 . 9 7
3 . 8 4
6 . 9 1
7 . 0 1
9 . 8 9
H 2 O
1
H N M R ( 500 M H z , d m s o)
O
N
O
CF
3
OH
MeO
19
F NMR Spectrum
1
H NMR Spectrum
124

6-(difluoromethoxy)-3-hydroxy-3-(trifluoromethyl)benzo[c]isoxazol-5(3H)-one (6i)

- 10 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 10 0 1 1 0 1 2 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
5 6 . 4 3
9 8 . 4 1
1 0 1 . 8 8
1 0 2 . 1 6
1 0 2 . 4 3
1 0 2 . 7 1
1 1 7 . 7 1
1 1 9 . 9 8
1 2 2 . 2 5
1 2 4 . 5 2
1 2 6 . 7 8
1 4 3 . 9 7
1 5 2 . 8 5
1 5 4 . 6 5
1 7 8 . 4 7
1 0 0 1 0 1 1 0 2 1 0 3 1 0 4 1 0 5
f 1 ( p p m )
0
2 0
4 0
6 0
8 0
1 0 0
1 0 1 . 8 8
1 0 2 . 1 6
1 0 2 . 4 3
1 0 2 . 7 1
1 1 6 1 1 8 1 2 0 1 2 2 1 2 4
f 1 ( p p m )
0
2 0
4 0
6 0
8 0
1 0 0
1 1 7 . 7 1
1 1 9 . 9 8
1 2 2 . 2 5
1 2 4 . 5 2
- 2 0 0 - 19 0 - 18 0 - 17 0 - 1 6 0 - 1 5 0 - 1 4 0 - 13 0 - 1 2 0 - 110 - 1 0 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0
f 1 ( p p m )
- 8 7 . 6 5
- 8 7 . 4 9
- 8 7 . 2 8
- 8 7 . 1 3
- 8 6 . 9 3
- 8 6 . 7 8
- 8 6 . 5 7
- 8 6 . 4 2
- 8 4 . 4 0
19
F N M R ( 470 M H z , dm s o ) \
O
N
O
CF
3
OH
HF
2
CO
19
F NMR Spectrum
13
C NMR Spectrum
125

- 2 - 1 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4
f 1 ( p p m )
0 . 9 1
1 . 2 5
0 . 9 6
1 . 0 0
7 . 0 6
7 . 1 8
7 . 3 2
7 . 4 7
7 . 5 5
1 0 . 1 2
e t h e r
1
H N M R ( 500 M H z , d m s o)
- 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 10 0 1 10 1 2 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
1 0 2 . 8 8
1 0 3 . 1 6
1 0 3 . 4 4
1 0 3 . 7 1
1 0 8 . 5 8
1 1 3 . 6 2
1 1 5 . 6 8
1 1 7 . 5 1
1 1 7 . 7 5
1 1 9 . 7 8
1 2 2 . 0 5
1 2 4 . 3 3
1 2 7 . 3 5
1 4 3 . 4 9
1 4 7 . 3 6
1 5 2 . 1 6
1 7 7 . 2 4
13
C N M R ( 12 6 M H z , dm s o)
1
H NMR Spectrum
13
C NMR Spectrum
126

1-(2-nitrosophenyl)-2,2,2-trifluoroethan-1-one (7a)

- 2 0 0 - 19 0 - 18 0 - 1 7 0 - 1 6 0 - 15 0 - 1 4 0 - 1 3 0 - 1 2 0 - 1 10 - 1 0 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0 3 0
f 1 ( p p m )
- 7 6 . 6 5
- 6 3 . 2 0
19
F N M R ( 470 M H z , c dc l 3 ) δ
- 2 - 1 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4
f 1 ( p p m )
7 . 4 5
7 . 4 5
7 . 4 7
7 . 4 7
7 . 4 8
7 . 8 8
7 . 8 8
7 . 8 8
7 . 8 9
7 . 8 9
7 . 8 9
7 . 9 1
7 . 9 1
7 . 9 1
8 . 0 0
8 . 0 0
8 . 0 0
8 . 0 1
8 . 0 1
8 . 0 2
8 . 0 3
8 . 0 3
8 . 0 3
8 . 7 8
8 . 8 0
7 . 8 0 7 . 8 5 7 . 9 0 7 . 9 5 8 . 0 0 8 . 0 5 8 . 1 0
f 1 ( p p m )
0
5 0
1 0 0
1 5 0
2 0 0
7 . 8 8
7 . 8 8
7 . 8 9
7 . 8 9
7 . 8 9
7 . 9 1
7 . 9 1
7 . 9 1
8 . 0 0
8 . 0 0
8 . 0 0
8 . 0 1
8 . 0 1
8 . 0 2
8 . 0 3
8 . 0 3
8 . 0 3
8 . 7 8 . 8
f 1 ( p p m )
0
1 0 0
2 0 0
8 . 7 8
8 . 8 0
7 . 4 0 7 . 4 5 7 . 5 0 7 . 5 5
f 1 ( p p m )
0
1 0 0
2 0 0
7 . 4 5
7 . 4 5
7 . 4 7
7 . 4 7
7 . 4 8
NO
O
CF
3
19
F NMR Spectrum
1
H NMR Spectrum
127

13
C NMR Spectrum

- 10 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 1 1 0 1 2 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
1 1 1 . 8 6
1 1 4 . 1 7
1 1 6 . 4 8
1 1 8 . 7 9
1 2 1 . 8 8
1 2 7 . 9 1
1 2 9 . 6 9
1 3 3 . 6 5
1 3 6 . 3 5
1 6 3 . 1 0
1 8 6 . 1 8
1 8 6 . 4 8
1 8 6 . 7 8
1 8 7 . 0 9
13
C N M R ( 126 M H z , c d c l 3 )
7 . 0 7 . 1 7 . 2 7 . 3 7 . 4 7 . 5 7 . 6 7 . 7 7 . 8 7 . 9 8 . 0 8 . 1 8 . 2 8 . 3 8 . 4 8 . 5 8 . 6 8 . 7 8 . 8 8 . 9 9 . 0 9 . 1
f 2 ( p p m )
1 2 0
1 2 5
1 3 0
1 3 5
1 4 0
1 4 5
f 1 ( p p m )
{ 7 . 8 9 , 1 3 6 . 3 4 }
{ 8 . 0 1 , 1 3 3 . 6 7 }
{ 8 . 7 8 , 1 2 9 . 7 5 }
{ 8 . 7 9 , 1 2 9 . 7 4 }
{ 7 . 4 6 , 1 2 7 . 9 9 }
1 3
C N M R ( 126 M H z , c dc l 3 )
1
H N M R ( 500 M H z , c dc l 3 )
HSQC Spectrum
128

2,2,2-trifluoro-1-(5-fluoro-2-nitrosophenyl)ethenone (7b)

7 . 2 7 . 3 7 . 4 7 . 5 7 . 6 7 . 7 7 . 8 7 . 9 8 . 0 8 . 1 8 . 2 8 . 3 8 . 4 8 . 5 8 . 6 8 . 7 8 . 8 8 . 9
f 2 ( p p m )
1 2 0
1 2 5
1 3 0
1 3 5
1 4 0
1 4 5
1 5 0
1 5 5
1 6 0
1 6 5
1 7 0
1 7 5
1 8 0
1 8 5
1 9 0
f 1 ( p p m )
{ 7 . 4 7 , 1 8 6 . 5 1 }
{ 8 . 0 2 , 1 6 2 . 9 8 } { 7 . 4 7 , 1 6 2 . 9 7 }
{ 8 . 8 0 , 1 3 6 . 2 4 }
{ 7 . 4 7 , 1 3 3 . 5 5 }
{ 7 . 9 0 , 1 2 9 . 6 4 }
{ 7 . 9 0 , 1 2 1 . 7 1 }
1 3
C N M R ( 1 26 M H z , c dc l 3 )
1
H N M R ( 50 0 M H z , c dc l 3 )
-200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20
f1 (ppm)
0.28
1.00
-96.50
-77.19
-63.72
HMBC Spectrum
19
F NMR Spectrum
NO
O
CF
3
F
129

1-(4-chloro-2-nitrosophenyl)-2,2,2-trifluoroethane-1,1-diol (8c)

- 2 0 0 - 19 0 - 1 8 0 - 17 0 - 1 6 0 - 15 0 - 14 0 - 13 0 - 1 2 0 - 1 10 - 1 0 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0
f 1 ( p p m )
- 8 4 . 2 8
- 6 3 . 7 2
19
F N M R ( 470 M H z , dm s o )
- 2 - 1 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4
f 1 ( p p m )
1 . 0 0
1 . 0 3
0 . 9 8
2 . 0 4
6 . 0 4
6 . 0 6
7 . 5 9
7 . 6 0
7 . 6 1
7 . 6 2
8 . 0 0
8 . 0 0
8 . 3 8
C H 3 C N
H 2 O
7 . 5 7 . 6 7 . 7 7 . 8 7 . 9 8 . 0
f 1 ( p p m )
0
1 0 0
2 0 0
1 . 0 3
0 . 9 8
7 . 5 9
7 . 6 0
7 . 6 1
7 . 6 2
8 . 0 0
8 . 0 0
NO
OH
CF
3
OH
Cl
19
F NMR Spectrum
1
H NMR Spectrum
130

1-(5-chloro-2-nitrosophenyl)-2,2,2-trifluoroethanone (7c)

- 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 1 1 0 1 2 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
9 3 . 2 3
9 3 . 4 9
9 3 . 7 6
9 4 . 0 2
1 0 9 . 4 6
1 1 9 . 9 1
1 2 2 . 2 1
1 2 4 . 5 1
1 2 6 . 8 2
1 3 0 . 0 6
1 3 0 . 3 3
1 3 4 . 4 8
1 3 9 . 5 6
1 3 9 . 8 0
1 6 2 . 3 2
C H 3 C N
- 2 0 0 - 19 0 - 18 0 - 1 7 0 - 16 0 - 15 0 - 1 4 0 - 1 3 0 - 12 0 - 1 10 - 1 0 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0 3 0
f 1 ( p p m )
- 7 6 . 6 2
- 6 3 . 2 1
19
F N M R ( 470 M H z , c dc l 3 )
NO
O
CF
3
Cl
19
F NMR Spectrum
13
C NMR Spectrum
131

- 2 - 1 0 1 2 3 4 5 6 7 8 9 1 0 11 12 1 3 14
f 1 ( p p m )
7 . 4 2
7 . 4 2
7 . 9 6
7 . 9 6
7 . 9 7
7 . 9 8
8 . 7 4
8 . 7 6
1
H N M R ( 500 M H z , c d c l 3 )
0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 10 0 1 1 0 1 2 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0
f 1 ( p p m )
1 1 1 . 6 9
1 1 4 . 0 0
1 1 6 . 3 1
1 1 8 . 6 3
1 2 3 . 3 7
1 2 8 . 2 6
1 3 0 . 7 2
1 3 3 . 5 4
1 4 3 . 9 9
1 6 1 . 1 1
1 8 4 . 7 2
1 8 5 . 0 3
1 8 5 . 3 4
1 8 5 . 6 5
1
H NMR Spectrum
13
C NMR Spectrum
132

HMBC Spectrum

2,2,2-trifluoro-1-(5-bromo-2-nitrosophenyl)ethenone (8d)

7 . 2 7 . 3 7 . 4 7 . 5 7 . 6 7 . 7 7 . 8 7 . 9 8 . 0 8 . 1 8 . 2 8 . 3 8 . 4 8 . 5 8 . 6 8 . 7 8 . 8 8 . 9 9 . 0 9 . 1
f 2 ( p p m )
1 2 0
1 3 0
1 4 0
1 5 0
1 6 0
1 7 0
1 8 0
1 9 0
2 0 0
f 1 ( p p m )
{ 7 . 4 3 , 1 8 5 . 1 5 }
{ 7 . 4 3 , 1 6 1 . 0 2 } { 7 . 9 8 , 1 6 1 . 0 2 }
{ 7 . 4 3 , 1 4 3 . 9 2 } { 7 . 9 8 , 1 4 3 . 9 2 } { 8 . 7 6 , 1 4 3 . 9 1 }
{ 7 . 4 3 , 1 3 3 . 4 6 }
{ 7 . 9 8 , 1 2 8 . 1 4 }
{ 8 . 7 7 , 1 2 3 . 2 3 }
1 3
C N M R ( 126 M H z , c dc l 3 )
1
H N M R ( 500 M H z , c dc l 3 )
- 2 0 0 - 19 0 - 18 0 - 17 0 - 1 6 0 - 15 0 - 14 0 - 13 0 - 1 2 0 - 11 0 - 1 0 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0
f 1 ( p p m )
- 8 4 . 2 9
19
F N M R ( 470 M H z , dm s o )
NO
OH
CF
3
OH
Br
19
F NMR Spectrum
133

- 1 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4
f 1 ( p p m )
1 . 0 0
1 . 0 0
1 . 1 3
2 . 2 3
5 . 9 2
5 . 9 4
7 . 7 3
7 . 7 3
7 . 7 4
7 . 7 5
8 . 1 5
8 . 1 5
8 . 3 6
H 2 O
C H 3 C N
6 . 0 6 . 5 7 . 0 7 . 5 8 . 0
f 1 ( p p m )
1 . 0 0
1 . 0 0
1 . 1 3
5 . 9 2
5 . 9 4
7 . 7 3
7 . 7 3
7 . 7 4
7 . 7 5
8 . 1 5
8 . 1 5
- 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 1 1 0 1 2 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
9 3 . 2 5
9 3 . 4 7
9 3 . 6 9
9 3 . 9 1
1 0 9 . 4 1
1 2 0 . 5 2
1 2 2 . 4 4
1 2 4 . 3 5
1 2 6 . 2 7
1 2 8 . 9 9
1 3 2 . 9 7
1 3 3 . 3 6
1 3 9 . 6 2
1 6 2 . 5 9
1
H NMR Spectrum
13
C NMR Spectrum
134

4 . 6 4 . 8 5 . 0 5 . 2 5 . 4 5 . 6 5 . 8 6 . 0 6 . 2 6 . 4 6 . 6 6 . 8 7 . 0 7 . 2 7 . 4 7 . 6 7 . 8 8 . 0 8 . 2 8 . 4 8 . 6 8 . 8 9 . 0 9 . 2 9 . 4 9 . 6
f 2 ( p p m )
4 . 0
4 . 5
5 . 0
5 . 5
6 . 0
6 . 5
7 . 0
7 . 5
8 . 0
8 . 5
9 . 0
f 1 ( p p m )
{ 8 . 3 6 , 8 . 3 6 }
{ 8 . 1 5 , 8 . 1 3 }
{ 7 . 7 3 , 7 . 7 4 }
{ 5 . 9 3 , 5 . 9 3 }
1
H N M R ( 600 M H z , d m s o)
1
5 . 2 5 . 4 5 . 6 5 . 8 6 . 0 6 . 2 6 . 4 6 . 6 6 . 8 7 . 0 7 . 2 7 . 4 7 . 6 7 . 8 8 . 0 8 . 2 8 . 4 8 . 6 8 . 8 9 . 0 9 . 2 9 . 4 9 . 6 9 . 8
f 2 ( p p m )
9 5
1 0 0
1 0 5
1 1 0
1 1 5
1 2 0
1 2 5
1 3 0
1 3 5
1 4 0
1 4 5
f 1 ( p p m )
{ 7 . 7 4 , 1 3 3 . 1 1 }
{ 8 . 1 5 , 1 3 2 . 6 6 }
{ 5 . 9 4 , 1 0 9 . 1 5 }
COSY Spectrum
HSQC Spectrum
135

2,2,2-trifluoro-1-(5-methoxy-2-nitrosophenyl)ethenone (7e)

- 2 0 0 - 19 0 - 18 0 - 17 0 - 16 0 - 15 0 - 1 4 0 - 13 0 - 1 2 0 - 1 10 - 10 0 - 9 0 - 8 0 - 7 0 - 6 0 - 5 0 - 4 0 - 3 0 - 2 0 - 1 0 0 1 0 2 0
f 1 ( p p m )
0 . 1 3
1 . 0 0 - 7 8 . 3 7
19
F N M R ( 564 M H z , dm s o ) .
- 1 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4
f 1 ( p p m )
3 . 2 4
1 . 0 4
1 . 1 2
1 . 0 0
4 . 0 5
7 . 2 8
7 . 2 8
7 . 6 5
7 . 6 5
7 . 6 6
7 . 6 7
9 . 3 2
9 . 3 3
7 . 0 7 . 5 8 . 0 8 . 5 9 . 0 9 . 5
f 1 ( p p m )
1 . 0 4
1 . 1 2
1 . 0 0
7 . 2 8
7 . 2 8
7 . 6 5
7 . 6 5
7 . 6 6
7 . 6 7
9 . 3 2
9 . 3 3
1
H N M R ( 600 M H z , d m s o)
NO
O
CF
3
MeO
19
F NMR Spectrum
1
H NMR Spectrum
136

- 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 10 0 1 1 0 12 0 13 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
5 7 . 5 4
1 1 5 . 2 5
1 1 7 . 2 8
1 1 8 . 1 4
1 2 0 . 0 2
1 2 1 . 9 1
1 2 2 . 1 4
1 2 3 . 8 0
1 3 8 . 7 1
1 6 1 . 0 6
1 6 7 . 7 1
1 8 4 . 4 2
1 8 4 . 6 6
1 8 4 . 9 1
1 8 5 . 1 6
1 1 5 12 0 12 5 13 0
f 1 ( p p m )
1 1 5 . 2 5
1 1 7 . 2 8
1 1 8 . 1 4
1 2 0 . 0 2
1 2 1 . 9 1
1 2 2 . 1 4
1 2 3 . 8 0
13
C N M R ( 15 1 M H z , dm s o)
6 . 6 6 . 8 7 . 0 7 . 2 7 . 4 7 . 6 7 . 8 8 . 0 8 . 2 8 . 4 8 . 6 8 . 8 9 . 0 9 . 2 9 . 4 9 . 6 9 . 8
f 2 ( p p m )
1 0 0
1 1 0
1 2 0
1 3 0
1 4 0
1 5 0
1 6 0
1 7 0
1 8 0
1 9 0
f 1 ( p p m )
{ 7 . 2 8 , 1 8 4 . 7 0 }
{ 9 . 3 3 , 1 6 7 . 6 4 }
{ 7 . 2 8 , 1 6 0 . 9 8 } { 7 . 6 6 , 1 6 0 . 9 8 }
{ 9 . 3 4 , 1 2 2 . 0 3 }
{ 7 . 2 8 , 1 1 7 . 2 1 }
{ 7 . 6 6 , 1 1 5 . 1 5 }
1 3
C N M R ( 151 M H z , dm s o)
1
H N M R ( 600 M H z , d m s o)
gH M B C A D
13
C NMR Spectrum
HMBC Spectrum
137

1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 4 . 0 4 . 5 5 . 0 5 . 5 6 . 0 6 . 5 7 . 0 7 . 5 8 . 0 8 . 5 9 . 0 9 . 5 1 0 . 0
f 2 ( p p m )
6 0
7 0
8 0
9 0
1 0 0
1 1 0
1 2 0
1 3 0
1 4 0
1 5 0
1 6 0
f 1 ( p p m )
{ 9 . 3 2 , 1 3 8 . 7 0 }
{ 7 . 6 6 , 1 1 7 . 2 4 }
{ 7 . 2 8 , 1 1 5 . 2 6 }
1 3
C N M R ( 151 M H z , dm s o)
1
H N M R ( 600 M H z , d m s o)
G H S Q C
HSQC Spectrum
138

NMR Study of 4e

19
F NMR spectra A) Irradiation at 2hrs 50mins B) The reaction mixture is left undisturbed for
24hrs C) On leaving the intermediate undisturbed for 36hrs shows formation of product.
-85.0 -84.5 -84.0 -83.5 -83.0 -82.5 -82.0 -81.5 -81.0 -80.5 -80.0 -79.5 -79.0 -78.5 -78.0
f1 (ppm)
1
2
3
4 e
4 e
3 e
6 e
A
B
C
I N T - 1
I n t e r m e d i a t e
139

13
C NMR spectra A) Irradiation at 2hrs 50mins B) The reaction mixture is left undisturbed for
24hrs C) On leaving the intermediate undisturbed for 36hrs shows formation of product

- 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 1 1 0 1 2 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
1
2
3
1 e
i n t e r m e d i a t e
i n t e r m e d i a t e
6 e
6 e 4 e
A
B
C
140

`
19
F NMR spectrum of 4e (-79.08 ppm) and intermediate (-84.43ppm) (standard- trifluorotoluene)

19
F NMR spectrum after 2hrs 30 min of irradiation of 4e in DMSO-d6
-110 -105 -100 -95 -90 -85 -80 -75 -70 -65 -60 -55 -50 -45 -40
f1 (ppm)
A (d)
-79.08
B (s)
-84.43
C (s)
-63.73
1.57
1.00
31.87
-84.43
-79.09
-79.07
-63.73
-63.71
19
F N M R ( 376 M H z , dm s o)
-98 -96 -94 -92 -90 -88 -86 -84 -82 -80 -78 -76 -74 -72 -70
f1 (ppm)
1.65
1.00
-84.45
-79.09
-79.08
i n t e r m e d i a t e
4 e
141

19
F NMR spectrum after 3hrs 50 mins of irradiation

19
F NMR spectrum after leaving the reaction mixture undisturbed for 12hrs
-86.5 -85.5 -84.5 -83.5 -82.5 -81.5 -80.5 -79.5 -78.5 -77.5 -76.5
f1 (ppm)
-84.60
-84.41
-78.41
-88.5 -87.5 -86.5 -85.5 -84.5 -83.5 -82.5 -81.5 -80.5 -79.5 -78.5 -77.5
f1 (ppm)
A (d)
-79.08
B (s)
-84.42
C (s)
-84.61
2.29
2.76
1.00
142

19
F NMR spectrum after leaving the reaction mixture undisturbed for 36hrs

1
H NMR spectrum assignments to intermediate
-92 -91 -90 -89 -88 -87 -86 -85 -84 -83 -82 -81 -80 -79 -78 -77 -76 -75 -74 -73 -72 -71
f1 (ppm)
-84.61
-79.09
-79.07
4 e
6 e
- 2 - 1 0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4
f 1 ( p p m )
2 . 4 0
3 . 8 3
1 . 0 0
1 . 2 4
1 . 3 7
0 . 9 6
0 . 9 5
1 . 3 3
0 . 8 5
2 . 6 4
4 e i n t
i n t
4 e
i n t
4 e
4 e
i n t
i n t
4 e
8 . 0 0 8 . 0 5 8 . 1 0 8 . 1 5 8 . 2 0
f 1 ( p p m )
0 . 8 5
2 . 6 4
7 . 0 7 . 1 7 . 2 7 . 3 7 . 4 7 . 5
f 1 ( p p m )
1 . 3 7
0 . 9 6
0 . 9 5
1 . 3 3
6 . 0 5 6 . 1 0 6 . 1 5 6 . 2 0 6 . 2 5
f 1 ( p p m )
1 . 0 0
1 . 2 4
i n t -
i n t e r m e d i a t e
143

13
C NMR spectrum after 2hr 30 min of irradiation

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220
f1 (ppm)
A (q)
94.21
B (q)
65.24
1.20
1.00
4 e
i n t e r m e d i a t e
13
C N M R ( 151 M H z , d m s o)
144

13
C NMR spectrum after leaving the reaction mixture undisturbed for 12hrs

13
C NMR spectrum after leaving the reaction undisturbed for 36hrs
-10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230
f1 (ppm)
CARBON_01
A (q)
103.29
B (q)
94.24
1.20
1.00 6 e
I n t e r m e d i a t e
- 1 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 1 1 0 1 2 0 1 3 0 1 4 0 1 5 0 1 6 0 1 7 0 1 8 0 1 9 0 2 0 0 2 1 0 2 2 0 2 3 0
f 1 ( p p m )
C A R B O N _ 0 1
f i n a l f o r m a t i o n o f p r o d u c t
6 e
145

NMR Study of 4a

19
F NMR spectrum of 4a and intermediate using trifluorotoluene as standard (after 3hrs 30mins)

- 9 1 - 9 0 - 8 9 - 8 8 - 8 7 - 8 6 - 8 5 - 8 4 - 8 3 - 8 2 - 8 1 - 8 0 - 7 9 - 7 8 - 7 7 - 7 6 - 7 5 - 7 4 - 7 3 - 7 2 - 7 1 - 7 0 - 6 9 - 6 8 - 6 7 - 6 6 - 6 5 - 6 4 - 6 3 - 6 2 - 6 1 - 6 0 - 5 9
f 1 ( p p m )
A ( d )
- 7 9 . 1 6
B ( s )
- 8 4 . 3 5
1 . 1 9
1 . 0 0
- 8 4 . 3 5
- 7 9 . 1 7
- 7 9 . 1 5
- 6 3 . 7 2
146

19
F NMR spectrum after 3hrs 30mins of irradiation of 4a in DMSO-d6

13
C NMR spectrum of 4a after 3hrs 30mins irradiation in DMSO-d6
5 . 1 5 . 2 5 . 3 5 . 4 5 . 5 5 . 6 5 . 7 5 . 8 5 . 9 6 . 0 6 . 1 6 . 2 6 . 3 6 . 4 6 . 5 6 . 6 6 . 7 6 . 8 6 . 9 7 . 0 7 . 1 7 . 2 7 . 3 7 . 4 7 . 5 7 . 6 7 . 7 7 . 8 7 . 9 8 . 0 8 . 1 8 . 2 8 . 3
f 1 ( p p m )
1 . 0 0
0 . 6 5
1 . 0 2
0 . 8 1
0 . 9 4
1 . 7 2
0 . 9 0
1 . 4 6
1 . 5 2
I N T
I N T
4 a
4 a
4 a
4 a + I N T
I N T
4 a
4
a
- 1 0 0 10 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 10 0 110 12 0 13 0 1 4 0 15 0 1 6 0 17 0 1 8 0 1 9 0 2 0 0 2 10 2 2 0 2 3 0
f 1 ( p p m )
A ( q )
9 3 . 9 8
B ( q )
6 5 . 2 1
2 . 6 9
1 . 0 0
6 4 . 9 0
6 5 . 1 1
6 5 . 3 1
6 5 . 5 2
9 3 . 6 6
9 3 . 8 7
9 4 . 0 9
9 4 . 3 1
147

Transmission Absorption Spectra of 4a - Oxygen Quenching Experiments

Argon
Oxygen
148

Crystal Structure Report for 5a

A clear light yellow prism-like specimen of C16H8F6N2O3, approximate dimensions 0.240 mm
x 0.352 mm x 0.572 mm, was used for the X-ray crystallographic analysis. The X-ray intensity
data were measured on a Bruker APEX DUO system equipped with a TRIUMPH curved-crystal
monochromator and a MoKα fine-focus tube (λ = 0.71073 Å).
Table 1: Data Collection details for 5a
Axis dx/mm 2 θ/ ° ω/ ° φ/ ° χ/ ° Width/ ° Frames Time/s Wavelength/Å Voltage/kV Current/mA Temperature/K
Omega 50.389 30.00 30.00 0.00 54.73 0.50 360 1.00 0.71073 50 30.0 101
Omega 50.389 30.00 30.00 72.00 54.73 0.50 360 1.00 0.71073 50 30.0 101
Omega 50.389 30.00 30.00 144.00 54.73 0.50 360 1.00 0.71073 50 30.0 101
Omega 50.389 30.00 30.00 216.00 54.73 0.50 360 1.00 0.71073 50 30.0 100
Omega 50.389 30.00 30.00 288.00 54.73 0.50 360 1.00 0.71073 50 30.0 100
Phi 50.389 30.00 0.00 0.00 54.73 0.50 720 1.00 0.71073 50 30.0 100

149

A total of 2520 frames were collected. The total exposure time was 0.70 hours. The frames were
integrated with the Bruker SAINT software package using a SAINT V8.34A (Bruker AXS, 2013)
algorithm. The integration of the data using an orthorhombic unit cell yielded a total
of 49111 reflections to a maximum θ angle of 31.48° (0.68 Å resolution), of which 4847 were
independent (average redundancy 10.132, completeness = 97.3%, Rint = 4.09%, Rsig = 2.19%)
and 3981 (82.13%) were greater than 2σ(F
2
). The final cell constants
of a = 16.3899(14) Å, b = 8.4422(8) Å, c = 21.6823(19) Å, volume = 3000.1(5) Å
3
, are based
upon the refinement of the XYZ-centroids of 9976 reflections above 20 σ(I) with 4.504° < 2θ
< 62.47°. Data were corrected for absorption effects using the multi-scan method (SADABS). The
ratio of minimum to maximum apparent transmission was 0.915. The calculated minimum and
maximum transmission coefficients (based on crystal size) are 0.9090 and 0.9610.

The structure was solved and refined using the Bruker SHELXTL Software Package, using the
space group P b c a, with Z = 8 for the formula unit, C16H8F6N2O3. The final anisotropic full-
matrix least-squares refinement on F
2
with 244 variables converged at R1 = 3.51%, for the
observed data and wR2 = 9.61% for all data. The goodness-of-fit was 1.037. The largest peak in
the final difference electron density synthesis was 0.498 e
-
/Å
3
and the largest hole was -0.381 e
-
/Å
3
with an RMS deviation of 0.057 e
-
/Å
3
. On the basis of the final model, the calculated density
was 1.728 g/cm
3
and F(000), 1568 e
-
.
Table 2: Sample and crystal data for 5a
Identification code Kavita091314
Chemical formula C 16H 8F 6N 2O 3
Formula weight 390.24 g/mol
150

Temperature 100(2) K
Wavelength 0.71073 Å
Crystal size 0.240 x 0.352 x 0.572 mm
Crystal habit clear light yellow prism
Crystal system orthorhombic
Space group P b c a
Unit cell dimensions a = 16.3899(14) Å α = 90 °
b = 8.4422(8) Å β = 90 °
c = 21.6823(19) Å γ = 90 °
Volume 3000.1(5) Å
3

Z 8
Density (calculated) 1.728 g/cm
3

Absorption coefficient 0.169 mm
-1

F(000) 1568

Table 3: Data collection and structure refinement for 5a
Diffractometer Bruker APEX DUO
Radiation source fine-focus tube, MoK α
Theta range for data collection 1.88 to 31.48 °
Index ranges -23<=h<=23, -12<=k<=12, -31<=l<=31
Reflections collected 49111
Independent reflections 4847 [R(int) = 0.0409]
Coverage of independent
reflections
97.3%
Absorption correction multi-scan
Max. and min. transmission 0.9610 and 0.9090
151

Structure solution technique direct methods
Structure solution program SHELXTL XT 2014/3 (Bruker AXS)
Refinement method Full-matrix least-squares on F
2

Refinement program SHELXTL XL 2014/3 (Bruker AXS)
Function minimized Σ w(F o
2
- F c
2
)
2

Data / restraints / parameters 4847 / 0 / 244
Goodness-of-fit on F
2
1.037
Δ/ σ
max 0.001
Final R indices
3981 data; I>2 σ
(I)
R1 = 0.0351, wR2 =
0.0890
all data
R1 = 0.0469, wR2 =
0.0961
Weighting scheme
w=1/[ σ
2
(F o
2
)+(0.0467P)
2
+1.2582P]
where P=(F o
2
+2F c
2
)/3
Largest diff. peak and hole 0.498 and -0.381 eÅ
-3

R.M.S. deviation from mean 0.057 eÅ
-3

Table 4: Atomic coordinates and equivalent isotropic
atomic displacement parameters (Å
2
) for 5a
U(eq) is defined as one third of the trace of the orthogonalized
Uij tensor.
x/a y/b z/c U(eq)
C1 0.61350(6) 0.55629(12) 0.34303(5) 0.01329(19)
C2 0.57753(6) 0.50495(12) 0.28840(5) 0.01352(19)
C3 0.62455(7) 0.41628(13) 0.24741(5) 0.0164(2)
C4 0.70522(7) 0.38001(14) 0.26146(5) 0.0192(2)
C5 0.74004(7) 0.43350(14) 0.31626(5) 0.0199(2)
152

x/a y/b z/c U(eq)
C6 0.69425(7) 0.52298(13) 0.35760(5) 0.0166(2)
C7 0.49071(6) 0.53517(13) 0.27062(5) 0.01492(19)
C8 0.42103(6) 0.46563(13) 0.31056(5) 0.0159(2)
C9 0.53472(6) 0.73429(12) 0.48302(5) 0.01325(18)
C10 0.57038(6) 0.83913(12) 0.52592(5) 0.01237(18)
C11 0.52239(6) 0.89797(13) 0.57422(5) 0.01424(19)
C12 0.44093(6) 0.85408(13) 0.57981(5) 0.0158(2)
C13 0.40647(6) 0.75064(13) 0.53723(5) 0.0163(2)
C14 0.45304(6) 0.69057(13) 0.48894(5) 0.0157(2)
C15 0.65643(6) 0.88658(12) 0.51748(5) 0.01406(19)
C16 0.70336(7) 0.95512(14) 0.57385(5) 0.0179(2)
F1 0.39271(4) 0.33607(9) 0.28183(4) 0.02505(17)
F2 0.35912(4) 0.56655(9) 0.31586(3) 0.02233(15)
F3 0.44442(4) 0.42182(8) 0.36712(3) 0.02037(15)
F4 0.78218(4) 0.97166(11) 0.56036(4) 0.02968(19)
F5 0.69717(5) 0.86074(10) 0.62294(3) 0.02469(16)
F6 0.67519(5) 0.09830(9) 0.59002(4) 0.02536(16)
N1 0.56452(5) 0.65327(10) 0.38451(4) 0.01310(17)
N2 0.58609(6) 0.65269(11) 0.44064(4) 0.01482(17)
O1 0.47095(5) 0.59173(12) 0.22195(4) 0.02345(19)
O2 0.50501(5) 0.72760(10) 0.36025(4) 0.01771(16)
O3 0.69417(5) 0.87444(11) 0.46965(4) 0.02064(17)

153

Table 5: Bond lengths (Å) for 5a.
C1-C6 1.3894(14) C1-C2 1.3922(14)
C1-N1 1.4573(13) C2-C3 1.3942(14)
C2-C7 1.4961(14) C3-C4 1.3909(15)
C3-H3 0.95 C4-C5 1.3934(16)
C4-H4 0.95 C5-C6 1.3919(15)
C5-H5 0.95 C6-H6 0.95
C7-O1 1.2028(13) C7-C8 1.5489(15)
C8-F2 1.3299(12) C8-F3 1.3371(12)
C8-F1 1.3417(13) C9-C14 1.3946(14)
C9-C10 1.4108(14) C9-N2 1.4239(13)
C10-C11 1.4007(14) C10-C15 1.4777(14)
C11-C12 1.3908(14) C11-H11 0.95
C12-C13 1.3907(15) C12-H12 0.95
C13-C14 1.3914(15) C13-H13 0.95
C14-H14 0.95 C15-O3 1.2119(13)
C15-C16 1.5557(15) C16-F4 1.3319(12)
C16-F5 1.3335(14) C16-F6 1.3406(14)
N1-N2 1.2674(12) N1-O2 1.2735(11)

Table 6: Bond angles (°) for 5a
C6-C1-C2 122.26(9) C6-C1-N1 119.87(9)
C2-C1-N1 117.82(9) C1-C2-C3 118.38(9)
C1-C2-C7 124.67(9) C3-C2-C7 116.94(9)
C4-C3-C2 120.27(10) C4-C3-H3 119.9
C2-C3-H3 119.9 C3-C4-C5 120.31(10)
154

C3-C4-H4 119.8 C5-C4-H4 119.8
C6-C5-C4 120.28(10) C6-C5-H5 119.9
C4-C5-H5 119.9 C1-C6-C5 118.49(10)
C1-C6-H6 120.8 C5-C6-H6 120.8
O1-C7-C2 123.36(10) O1-C7-C8 116.26(10)
C2-C7-C8 119.52(9) F2-C8-F3 108.47(9)
F2-C8-F1 107.36(9) F3-C8-F1 107.43(9)
F2-C8-C7 111.60(9) F3-C8-C7 113.96(9)
F1-C8-C7 107.73(9) C14-C9-C10 120.20(9)
C14-C9-N2 119.93(9) C10-C9-N2 118.95(9)
C11-C10-C9 118.88(9) C11-C10-C15 122.17(9)
C9-C10-C15 118.93(9) C12-C11-C10 120.64(10)
C12-C11-H11 119.7 C10-C11-H11 119.7
C13-C12-C11 119.95(10) C13-C12-H12 120.0
C11-C12-H12 120.0 C12-C13-C14 120.37(10)
C12-C13-H13 119.8 C14-C13-H13 119.8
C13-C14-C9 119.96(10) C13-C14-H14 120.0
C9-C14-H14 120.0 O3-C15-C10 124.77(10)
O3-C15-C16 116.84(9) C10-C15-C16 118.39(9)
F4-C16-F5 108.16(9) F4-C16-F6 107.28(10)
F5-C16-F6 107.68(9) F4-C16-C15 110.24(9)
F5-C16-C15 111.55(9) F6-C16-C15 111.75(9)
N2-N1-O2 127.75(9) N2-N1-C1 115.91(9)
O2-N1-C1 116.34(8) N1-N2-C9 116.93(9)

155

Table 7: Anisotropic atomic displacement parameters (Å
2
) for 5a
The anisotropic atomic displacement factor exponent takes the form: -2π
2
[ h
2
a
*2
U11 + ... + 2 h k
a
*
b
*
U12 ]
U 11 U 22 U 33 U 23 U 13 U 12
C1 0.0135(4) 0.0133(4) 0.0130(4) -0.0007(3) 0.0020(3) 0.0006(3)
C2 0.0128(4) 0.0141(4) 0.0136(4) 0.0002(3) 0.0011(3) -0.0008(3)
C3 0.0161(4) 0.0177(5) 0.0155(5) -0.0033(4) 0.0019(4) -0.0021(4)
C4 0.0150(5) 0.0212(5) 0.0215(5) -0.0051(4) 0.0044(4) 0.0002(4)
C5 0.0129(4) 0.0228(5) 0.0240(5) -0.0037(4) 0.0004(4) 0.0020(4)
C6 0.0148(4) 0.0190(5) 0.0160(5) -0.0017(4) -0.0012(4) -0.0002(4)
C7 0.0146(4) 0.0170(5) 0.0131(4) -0.0021(4) -0.0003(3) 0.0002(4)
C8 0.0128(4) 0.0168(5) 0.0181(5) 0.0012(4) -0.0014(4) 0.0014(4)
C9 0.0136(4) 0.0152(4) 0.0109(4) 0.0004(3) -0.0002(3) 0.0013(3)
C10 0.0117(4) 0.0146(4) 0.0108(4) 0.0011(3) -0.0008(3) 0.0007(3)
C11 0.0147(4) 0.0168(5) 0.0112(4) -0.0005(4) -0.0014(3) 0.0022(4)
C12 0.0146(4) 0.0203(5) 0.0126(4) 0.0006(4) 0.0013(3) 0.0028(4)
C13 0.0126(4) 0.0203(5) 0.0161(5) 0.0028(4) 0.0003(4) 0.0000(4)
C14 0.0145(4) 0.0173(5) 0.0152(5) -0.0007(4) -0.0017(4) -0.0016(4)
C15 0.0128(4) 0.0151(4) 0.0143(4) -0.0001(4) -0.0013(3) 0.0003(3)
C16 0.0127(4) 0.0234(5) 0.0176(5) -0.0021(4) -0.0019(4) -0.0002(4)
F1 0.0184(3) 0.0220(4) 0.0347(4) -0.0049(3) -0.0039(3) -0.0041(3)
F2 0.0158(3) 0.0244(3) 0.0268(4) 0.0042(3) 0.0037(3) 0.0073(3)
F3 0.0190(3) 0.0237(3) 0.0185(3) 0.0077(3) 0.0009(2) -0.0002(3)
F4 0.0119(3) 0.0497(5) 0.0274(4) -0.0080(4) -0.0013(3) -0.0060(3)
F5 0.0250(4) 0.0322(4) 0.0169(3) 0.0033(3) -0.0065(3) 0.0008(3)
F6 0.0256(4) 0.0216(3) 0.0289(4) -0.0088(3) -0.0052(3) -0.0012(3)
156

U 11 U 22 U 33 U 23 U 13 U 12
N1 0.0125(4) 0.0133(4) 0.0135(4) -0.0003(3) -0.0002(3) -0.0001(3)
N2 0.0144(4) 0.0172(4) 0.0128(4) -0.0020(3) -0.0004(3) 0.0001(3)
O1 0.0208(4) 0.0357(5) 0.0139(4) 0.0038(3) -0.0023(3) 0.0029(4)
O2 0.0178(4) 0.0195(4) 0.0158(4) 0.0013(3) -0.0023(3) 0.0070(3)
O3 0.0166(4) 0.0280(4) 0.0172(4) -0.0024(3) 0.0032(3) -0.0031(3)

Table 8: Hydrogen atomic coordinates and
isotropic atomic displacement parameters
(Å
2
) for 5a
x/a y/b z/c U(eq)
H3 0.6014 0.3805 0.2097 0.02
H4 0.7367 0.3185 0.2336 0.023
H5 0.7953 0.4088 0.3255 0.024
H6 0.7177 0.5604 0.3949 0.02
H11 0.5457 0.9685 0.6034 0.017
H12 0.4089 0.8947 0.6127 0.019
H13 0.3508 0.7208 0.5411 0.02
H14 0.4292 0.6198 0.4600 0.019

157

Crystal Structure Report for 5f

A orange prism-like specimen of C20H16F6N2O7, approximate dimensions 0.120 mm x 0.190 mm
x 0.250 mm, was used for the X-ray crystallographic analysis. The X-ray intensity data were
measured on a Bruker APEX DUO system equipped with a TRIUMPH curved-crystal
monochromator and a MoKα fine-focus tube (λ = 0.71073 Å).
Table 1: Data collection details for 5f
Axis dx/mm 2 θ/ ° ω/ ° φ/ ° χ/ ° Width/ ° Frames Time/s Wavelength/Å Voltage/kV Current/mA Temperature/K
Omega 50.534 30.00 30.00 0.00 54.75 -0.50 360 10.00 0.71073 50 30.0 100
Omega 50.534 30.00 30.00 72.00 54.75 -0.50 319 10.00 0.71073 50 30.0 100
Omega 50.534 30.00 30.00 0.00 54.75 -0.50 360 20.00 0.71073 50 30.0 100
Omega 50.534 30.00 30.00 72.00 54.75 -0.50 360 20.00 0.71073 50 30.0 100
Omega 50.534 30.00 30.00 144.00 54.75 -0.50 360 20.00 0.71073 50 30.0 100
158

Axis dx/mm 2 θ/ ° ω/ ° φ/ ° χ/ ° Width/ ° Frames Time/s Wavelength/Å Voltage/kV Current/mA Temperature/K
Omega 50.534 30.00 30.00 216.00 54.75 -0.50 360 20.00 0.71073 50 30.0 100
Omega 50.534 30.00 30.00 288.00 54.75 -0.50 360 20.00 0.71073 50 30.0 100
Phi 50.534 30.00 0.00 0.00 54.75 -0.50 720 20.00 0.71073 50 30.0 100

A total of 3199 frames were collected. The total exposure time was 15.89 hours. The frames were
integrated with the Bruker SAINT software package using a SAINT V8.38A (Bruker AXS, 2013)
algorithm. The integration of the data using a triclinic unit cell yielded a total of 11348 reflections
to a maximum θ angle of 28.27° (0.75 Å resolution), of which 2714 were independent (average
redundancy 4.181, completeness = 99.8%, Rint = 3.96%, Rsig = 3.94%) and 1823 (67.17%) were
greater than 2σ(F
2
). The final cell constants of a = 4.766(2) Å, b = 9.398(5) Å, c = 12.710(6) Å, α
= 104.348(8)°, β = 97.123(8)°, γ = 91.867(8)°, volume = 546.1(5) Å
3
, are based upon the
refinement of the XYZ-centroids of 4283 reflections above 20 σ(I) with 4.483° < 2θ
< 61.21°. Data were corrected for absorption effects using the multi-scan method (SADABS). The
ratio of minimum to maximum apparent transmission was 0.851. The calculated minimum and
maximum transmission coefficients (based on crystal size) are 0.9640 and 0.9820.

The structure was solved and refined using the Bruker SHELXTL Software Package, using the
space group P -1, with Z = 1 for the formula unit, C20H16F6N2O7. The final anisotropic full-matrix
least-squares refinement on F
2
with 320 variables converged at R1 = 7.64%, for the observed data
and wR2 = 22.22% for all data. The goodness-of-fit was 1.136. The largest peak in the final
difference electron density synthesis was 0.539 e
-
/Å
3
and the largest hole was -0.246 e
-
/Å
3
with an
RMS deviation of 0.062 e
-
/Å
3
. On the basis of the final model, the calculated density
was 1.552 g/cm
3
and F(000), 260 e
-
.
159

Table 2: Sample and crystal data for 5f
Identification code Kavita110216b
Chemical formula C 20H 16F 6N 2O 7
Formula weight 510.35 g/mol
Temperature 100(2) K
Wavelength 0.71073 Å
Crystal size 0.120 x 0.190 x 0.250 mm
Crystal habit orange prism
Crystal system triclinic
Space group P -1
Unit cell dimensions a = 4.766(2) Å α = 104.348(8) °
b = 9.398(5) Å β = 97.123(8) °
c = 12.710(6) Å γ = 91.867(8) °
Volume 546.1(5) Å
3

Z 1
Density (calculated) 1.552 g/cm
3

Absorption coefficient 0.149 mm
-1

F(000) 260

Table 3: Data collection and structure refinement for 5f
Diffractometer Bruker APEX DUO
Radiation source fine-focus tube, MoK α
Theta range for data collection 1.67 to 28.27 °
Index ranges -6<=h<=6, -12<=k<=12, -16<=l<=16
Reflections collected 11348
160

Independent reflections 2714 [R(int) = 0.0396]
Coverage of independent
reflections
99.8%
Absorption correction multi-scan
Max. and min. transmission 0.9820 and 0.9640
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 2016/6 (Bruker AXS, 2016)
Function minimized Σ w(F o
2
- F c
2
)
2

Data / restraints / parameters 2714 / 288 / 320
Goodness-of-fit on F
2
1.136
Δ/σmax 0.001
Final R indices
1823 data; I>2 σ
(I)
R1 = 0.0764, wR2 =
0.2042
all data
R1 = 0.1144, wR2 =
0.2222
Weighting scheme
w=1/[ σ
2
(F o
2
)+(0.0794P)
2
+0.6628P]
where P=(F o
2
+2F c
2
)/3
Largest diff. peak and hole 0.539 and -0.246 eÅ
-3

R.M.S. deviation from mean 0.062 eÅ
-3

Table 4: Atomic coordinates and equivalent
isotropic atomic displacement parameters (Å
2
) for
5f
U(eq) is defined as one third of the trace of the
orthogonalized Uij tensor.
161

x/a y/b z/c U(eq)
C1 0.631(2) 0.5755(12) 0.3613(7) 0.0206(17)
C2 0.6040(12) 0.5622(7) 0.2485(5) 0.0268(11)
C3 0.7742(12) 0.6557(7) 0.2085(5) 0.0317(12)
C4 0.9740(15) 0.7579(9) 0.2809(7) 0.0272(14)
C5 0.0068(17) 0.7671(9) 0.3938(7) 0.0217(15)
C6 0.8353(11) 0.6777(6) 0.4346(5) 0.0200(10)
C7 0.4108(15) 0.4508(9) 0.1648(6) 0.0318(14)
C8 0.4825(17) 0.2863(8) 0.1430(5) 0.0396(15)
C9 0.101(2) 0.8643(12) 0.1367(7) 0.062(3)
C10 0.254(2) 0.8816(15) 0.5709(9) 0.029(2)
C11 0.3199(10) 0.4172(5) 0.5568(4) 0.0196(9)
C12 0.388(2) 0.4498(13) 0.6742(7) 0.0237(18)
C13 0.2514(13) 0.3678(7) 0.7307(5) 0.0284(11)
C14 0.0431(15) 0.2564(8) 0.6758(8) 0.0264(14)
C15 0.9684(19) 0.2300(10) 0.5633(6) 0.0236(16)
C16 0.1054(11) 0.3090(6) 0.5043(5) 0.0223(10)
C17 0.6060(12) 0.5691(6) 0.7336(4) 0.0285(11)
C18 0.6062(19) 0.6271(14) 0.8580(6) 0.049(2)
C19 0.997(2) 0.1757(10) 0.8409(6) 0.054(2)
C20 0.672(2) 0.0918(15) 0.4017(9) 0.031(2)
F1 0.6695(10) 0.2553(4) 0.2187(3) 0.0543(11)
F2 0.2466(19) 0.1989(7) 0.1288(6) 0.0559(17)
F3 0.5954(10) 0.2519(5) 0.0479(3) 0.0583(12)
F4 0.707(3) 0.5297(17) 0.9121(12) 0.089(4)
F5 0.7743(19) 0.7517(10) 0.8982(6) 0.085(3)
162

x/a y/b z/c U(eq)
F6 0.3550(10) 0.6560(6) 0.8880(4) 0.0742(16)
N1 0.4428(8) 0.4866(5) 0.4014(3) 0.0204(8)
N2 0.520(6) 0.491(4) 0.493(2) 0.018(3)
O1 0.236(3) 0.4788(12) 0.0967(12) 0.0395(18)
O2 0.146(2) 0.8544(11) 0.2491(7) 0.0383(17)
O3 0.214(4) 0.871(2) 0.4550(10) 0.029(2)
O4 0.247(2) 0.4059(11) 0.3287(7) 0.0342(16)
O5 0.775(3) 0.6320(14) 0.6967(9) 0.061(3)
O6 0.9032(18) 0.1686(10) 0.7269(7) 0.0357(16)
O7 0.762(4) 0.124(3) 0.5189(10) 0.027(2)

Table 5: Bond lengths (Å) for 5f
C1-C2 1.397(9) C1-C6 1.418(10)
C1-N1 1.427(10) C2-C3 1.402(8)
C2-C7 1.490(10) C3-C4 1.400(9)
C3-H3 0.95 C4-O2 1.368(8)
C4-C5 1.405(10) C5-O3 1.380(16)
C5-C6 1.385(9) C6-H6 0.95
C7-O1 1.209(14) C7-C8 1.559(10)
C8-F1 1.323(8) C8-F2 1.336(10)
C8-F3 1.354(8) C9-O2 1.444(10)
C9-H9A 0.98 C9-H9B 0.98
C9-H9C 0.98 C10-O3 1.439(12)
C10-H10A 0.98 C10-H10B 0.98
C10-H10C 0.98 C11-C16 1.397(7)
163

C11-C12 1.439(8) C11-N2 1.57(3)
C12-C13 1.375(12) C12-C17 1.489(11)
C13-C14 1.402(10) C13-H13 0.95
C14-O6 1.373(8) C14-C15 1.387(9)
C15-O7 1.344(18) C15-C16 1.380(10)
C16-H16 0.95 C17-O5 1.193(15)
C17-C18 1.539(9) C18-F6 1.317(11)
C18-F4 1.342(19) C18-F5 1.347(12)
C19-O6 1.447(10) C19-H19A 0.98
C19-H19B 0.98 C19-H19C 0.98
C20-O7 1.450(12) C20-H20A 0.98
C20-H20B 0.98 C20-H20C 0.98
N1-N2 1.16(3) N1-O4 1.301(9)

Table 6: Bond angles (°) for 5f
C2-C1-C6 120.7(8) C2-C1-N1 118.6(7)
C6-C1-N1 120.7(6) C1-C2-C3 119.2(7)
C1-C2-C7 124.5(6) C3-C2-C7 116.2(5)
C4-C3-C2 120.1(6) C4-C3-H3 120.0
C2-C3-H3 120.0 O2-C4-C3 123.9(8)
O2-C4-C5 115.7(7) C3-C4-C5 120.4(7)
O3-C5-C6 125.9(10) O3-C5-C4 114.1(9)
C6-C5-C4 120.0(7) C5-C6-C1 119.5(7)
C5-C6-H6 120.3 C1-C6-H6 120.3
O1-C7-C2 124.8(8) O1-C7-C8 115.2(8)
C2-C7-C8 118.3(5) F1-C8-F2 109.4(6)
164

F1-C8-F3 106.8(7) F2-C8-F3 107.2(6)
F1-C8-C7 115.1(5) F2-C8-C7 110.5(7)
F3-C8-C7 107.5(6) O2-C9-H9A 109.5
O2-C9-H9B 109.5 H9A-C9-H9B 109.5
O2-C9-H9C 109.5 H9A-C9-H9C 109.5
H9B-C9-H9C 109.5 O3-C10-H10A 109.5
O3-C10-H10B 109.5 H10A-C10-H10B 109.5
O3-C10-H10C 109.5 H10A-C10-H10C 109.5
H10B-C10-H10C 109.5 C16-C11-C12 119.0(6)
C16-C11-N2 122.9(12) C12-C11-N2 117.5(13)
C13-C12-C11 119.0(7) C13-C12-C17 120.4(7)
C11-C12-C17 120.6(8) C12-C13-C14 120.9(7)
C12-C13-H13 119.6 C14-C13-H13 119.6
O6-C14-C15 116.3(7) O6-C14-C13 123.8(8)
C15-C14-C13 119.9(7) O7-C15-C16 124.3(9)
O7-C15-C14 115.3(9) C16-C15-C14 120.4(7)
C15-C16-C11 120.6(6) C15-C16-H16 119.7
C11-C16-H16 119.7 O5-C17-C12 128.4(7)
O5-C17-C18 114.4(7) C12-C17-C18 117.1(6)
F6-C18-F4 105.8(9) F6-C18-F5 106.8(10)
F4-C18-F5 106.5(9) F6-C18-C17 114.7(6)
F4-C18-C17 111.3(11) F5-C18-C17 111.2(7)
O6-C19-H19A 109.5 O6-C19-H19B 109.5
H19A-C19-H19B 109.5 O6-C19-H19C 109.5
H19A-C19-H19C 109.5 H19B-C19-H19C 109.5
O7-C20-H20A 109.5 O7-C20-H20B 109.5
165

H20A-C20-H20B 109.5 O7-C20-H20C 109.5
H20A-C20-H20C 109.5 H20B-C20-H20C 109.5
N2-N1-O4 133.0(18) N2-N1-C1 110.5(17)
O4-N1-C1 115.9(6) N1-N2-C11 118.(3)
C4-O2-C9 118.9(8) C5-O3-C10 115.3(14)
C14-O6-C19 119.2(8) C15-O7-C20 118.0(13)

Table 7: Torsion angles (°) for 5f
C6-C1-C2-C3 -2.6(13) N1-C1-C2-C3 175.8(7)
C6-C1-C2-C7 175.3(7) N1-C1-C2-C7 -6.3(13)
C1-C2-C3-C4 1.9(10) C7-C2-C3-C4 -176.2(6)
C2-C3-C4-O2 -179.1(8) C2-C3-C4-C5 0.4(10)
O2-C4-C5-O3 -1.5(16) C3-C4-C5-O3 179.0(13)
O2-C4-C5-C6 177.6(8) C3-C4-C5-C6 -1.9(11)
O3-C5-C6-C1 -179.9(15) C4-C5-C6-C1 1.1(11)
C2-C1-C6-C5 1.2(13) N1-C1-C6-C5 -177.3(8)
C1-C2-C7-O1 125.9(12) C3-C2-C7-O1 -56.1(12)
C1-C2-C7-C8 -69.9(10) C3-C2-C7-C8 108.1(7)
O1-C7-C8-F1 -178.7(10) C2-C7-C8-F1 15.6(10)
O1-C7-C8-F2 -54.2(11) C2-C7-C8-F2 140.1(6)
O1-C7-C8-F3 62.6(11) C2-C7-C8-F3 -103.1(6)
C16-C11-C12-C13 3.7(13) N2-C11-C12-C13 -168.3(15)
C16-C11-C12-C17 -177.2(7) N2-C11-C12-C17 10.8(18)
C11-C12-C13-C14 -1.7(14) C17-C12-C13-C14 179.2(8)
C12-C13-C14-O6 178.6(9) C12-C13-C14-C15 -1.4(11)
O6-C14-C15-O7 1.7(16) C13-C14-C15-O7 -178.3(13)
166

O6-C14-C15-C16 -177.5(7) C13-C14-C15-C16 2.5(12)
O7-C15-C16-C11 -179.5(14) C14-C15-C16-C11 -0.4(11)
C12-C11-C16-C15 -2.7(10) N2-C11-C16-C15 168.9(15)
C13-C12-C17-O5 165.8(12) C11-C12-C17-O5 -13.2(18)
C13-C12-C17-C18 -18.2(14) C11-C12-C17-C18 162.8(9)
O5-C17-C18-F6 129.7(12) C12-C17-C18-F6 -46.9(14)
O5-C17-C18-F4 -110.2(13) C12-C17-C18-F4 73.2(11)
O5-C17-C18-F5 8.3(15) C12-C17-C18-F5 -168.2(10)
C2-C1-N1-N2 168.0(17) C6-C1-N1-N2 -13.5(19)
C2-C1-N1-O4 -4.3(13) C6-C1-N1-O4 174.2(9)
O4-N1-N2-C11 -17.(4) C1-N1-N2-C11 172.0(17)
C16-C11-N2-N1 21.(3) C12-C11-N2-N1 -167.1(19)
C3-C4-O2-C9 7.0(14) C5-C4-O2-C9 -172.5(9)
C6-C5-O3-C10 1.(3) C4-C5-O3-C10 -179.5(13)
C15-C14-O6-C19 171.3(8) C13-C14-O6-C19 -8.6(12)
C16-C15-O7-C20 -1.(3) C14-C15-O7-C20 179.3(13)

Table 8: Anisotropic atomic displacement parameters (Å
2
) for 5f
The anisotropic atomic displacement factor exponent takes the form: -2π
2
[ h
2
a
*2
U11 +
... + 2 h k a
*
b
*
U12 ]
U 11 U 22 U 33 U 23 U 13 U 12
C1 0.020(3) 0.026(4) 0.019(4) 0.009(3) 0.010(3) 0.002(2)
C2 0.025(3) 0.036(3) 0.023(3) 0.014(2) 0.007(2) -0.004(2)
C3 0.033(3) 0.040(3) 0.025(3) 0.015(2) 0.003(2) -0.005(2)
C4 0.026(3) 0.035(4) 0.026(4) 0.015(3) 0.008(3) -0.002(2)
C5 0.021(3) 0.022(3) 0.023(4) 0.009(4) 0.003(3) -0.003(2)
167

U 11 U 22 U 33 U 23 U 13 U 12
C6 0.021(2) 0.022(3) 0.019(3) 0.009(2) 0.004(2) 0.0021(19)
C7 0.027(3) 0.042(4) 0.027(3) 0.010(3) 0.002(2) -0.001(3)
C8 0.052(4) 0.036(3) 0.026(3) 0.005(3) -0.007(3) 0.001(3)
C9 0.087(7) 0.078(6) 0.027(4) 0.022(4) 0.015(4) -0.018(5)
C10 0.027(5) 0.030(5) 0.031(5) 0.008(4) 0.003(3) -0.001(4)
C11 0.021(2) 0.022(2) 0.018(2) 0.0069(18) 0.0061(17) 0.0041(18)
C12 0.027(3) 0.029(4) 0.015(3) 0.006(3) 0.007(3) 0.001(3)
C13 0.034(3) 0.034(3) 0.022(3) 0.012(2) 0.011(2) 0.003(2)
C14 0.032(3) 0.030(3) 0.023(4) 0.013(3) 0.014(3) 0.003(2)
C15 0.021(3) 0.029(3) 0.023(3) 0.009(3) 0.006(3) 0.006(2)
C16 0.021(2) 0.028(3) 0.019(3) 0.008(2) 0.000(2) 0.0009(19)
C17 0.032(3) 0.035(3) 0.019(2) 0.008(2) -0.0006(19) 0.000(2)
C18 0.040(4) 0.074(6) 0.024(3) -0.002(4) -0.001(3) -0.018(4)
C19 0.083(6) 0.059(5) 0.024(4) 0.016(3) 0.015(4) -0.010(4)
C20 0.029(5) 0.038(6) 0.027(5) 0.011(4) 0.004(3) -0.005(4)
F1 0.075(3) 0.045(2) 0.0358(19) 0.0060(16) -0.0126(18) 0.013(2)
F2 0.072(3) 0.049(3) 0.042(4) 0.008(2) 0.000(3) -0.017(2)
F3 0.069(3) 0.069(3) 0.0268(18) -0.0033(19) 0.0028(18) 0.008(2)
F4 0.082(8) 0.154(8) 0.040(4) 0.051(5) -0.012(5) -0.019(5)
F5 0.077(4) 0.122(7) 0.033(3) -0.013(3) 0.006(3) -0.064(5)
F6 0.060(3) 0.077(3) 0.065(3) -0.029(3) 0.033(2) -0.024(2)
N1 0.0176(19) 0.026(2) 0.0174(19) 0.0060(16) 0.0019(14) -0.0028(16)
N2 0.018(7) 0.022(7) 0.016(5) 0.001(5) 0.009(3) 0.005(5)
O1 0.027(3) 0.054(4) 0.038(4) 0.019(3) -0.010(3) -0.003(2)
O2 0.044(4) 0.045(4) 0.031(4) 0.017(3) 0.013(3) -0.012(3)
168

U 11 U 22 U 33 U 23 U 13 U 12
O3 0.033(4) 0.029(3) 0.028(5) 0.013(5) 0.004(4) -0.008(3)
O4 0.040(3) 0.037(4) 0.024(4) 0.008(3) 0.004(2) -0.010(3)
O5 0.086(5) 0.059(7) 0.030(5) 0.001(4) 0.007(4) -0.037(4)
O6 0.043(4) 0.042(4) 0.029(3) 0.016(3) 0.016(3) -0.003(3)
O7 0.025(4) 0.035(4) 0.026(5) 0.017(4) 0.009(4) -0.003(3)

Table 9: Hydrogen atomic coordinates and
isotropic atomic displacement parameters
(Å
2
) for 5f
x/a y/b z/c U(eq)
H3 0.7540 0.6496 0.1322 0.038
H6 0.8545 0.6848 0.5110 0.024
H9A 1.0988 0.7657 0.0875 0.093
H9B 1.2552 0.9270 0.1239 0.093
H9C 0.9199 0.9069 0.1225 0.093
H10A 1.2939 0.7850 0.5833 0.044
H10B 1.0819 0.9148 0.6017 0.044
H10C 1.4139 0.9525 0.6066 0.044
H13 0.2988 0.3868 0.8079 0.034
H16 0.0532 0.2896 0.4272 0.027
H19A 0.1823 0.1336 0.8475 0.081
H19B -0.1404 0.1196 0.8687 0.081
H19C 0.0140 0.2785 0.8837 0.081
H20A -0.1668 0.0615 0.3625 0.046
H20B -0.4005 0.1802 0.3831 0.046
169

x/a y/b z/c U(eq)
H20C -0.4783 0.0123 0.3804 0.046

Crystal Structure Report for 5h

A clear orange prism-like specimen of C24H12F6N2O3, approximate dimensions 0.102 mm
x 0.133 mm x 0.471 mm, was used for the X-ray crystallographic analysis. The X-ray intensity
data were measured on a Bruker APEX DUO system equipped with a TRIUMPH curved-crystal
monochromator and a MoKα fine-focus tube (λ = 0.71073 Å)
Table 1: Data collection details for 5h
Axis dx/mm 2 θ/ ° ω/ ° φ/ ° χ/ ° Width/ ° Frames Time/s Wavelength/Å Voltage/kV Current/mA Temperature/K
Omega 50.355 30.00 30.00 0.00 54.73 0.50 360 10.00 0.71073 50 30.0 100
Omega 50.355 30.00 30.00 72.00 54.73 0.50 360 10.00 0.71073 50 30.0 100
170

Axis dx/mm 2 θ/ ° ω/ ° φ/ ° χ/ ° Width/ ° Frames Time/s Wavelength/Å Voltage/kV Current/mA Temperature/K
Omega 50.355 30.00 30.00 144.00 54.73 0.50 360 10.00 0.71073 50 30.0 100
Omega 50.355 30.00 30.00 216.00 54.73 0.50 360 10.00 0.71073 50 30.0 100
Omega 50.355 30.00 30.00 288.00 54.73 0.50 360 10.00 0.71073 50 30.0 100
Phi 50.355 30.00 0.00 0.00 54.73 0.50 720 10.00 0.71073 50 30.0 100

A total of 2520 frames were collected. The total exposure time was 7.00 hours. The frames were
integrated with the Bruker SAINT software package using a SAINT V8.34A (Bruker AXS, 2013)
algorithm. The integration of the data using a triclinic unit cell yielded a total of 25775 reflections
to a maximum θ angle of 30.52° (0.70 Å resolution), of which 6216 were independent (average
redundancy 4.147, completeness = 98.8%, Rint = 3.27%, Rsig = 2.93%) and 4814 (77.45%) were
greater than 2σ(F
2
). The final cell constants
of a = 7.9032(8) Å, b = 8.8144(10) Å, c = 14.8800(16) Å, α = 93.280(2)°, β = 95.688(2)°, γ
= 90.365(2)°, volume = 1029.70(19) Å
3
, are based upon the refinement of the XYZ-centroids
of 9951 reflections above 20 σ(I) with 4.634° < 2θ < 61.07°.Data were corrected for absorption
effects using the multi-scan method (SADABS). The ratio of minimum to maximum apparent
transmission was 0.869. The calculated minimum and maximum transmission coefficients (based
on crystal size) are 0.9360 and 0.9860.

The structure was solved and refined using the Bruker SHELXTL Software Package, using the
space group P -1, with Z = 2 for the formula unit, C24H12F6N2O3. The final anisotropic full-matrix
least-squares refinement on F
2
with 316 variables converged at R1 = 4.58%, for the observed data
and wR2 = 12.91% for all data. The goodness-of-fit was 1.040. The largest peak in the final
difference electron density synthesis was 0.668 e
-
/Å
3
and the largest hole was -0.358 e
-
/Å
3
with an
171

RMS deviation of 0.061 e
-
/Å
3
. On the basis of the final model, the calculated density
was 1.582 g/cm
3
and F(000), 496 e
-
.
Table 2: Sample and crystal data for 5h
Identification code Kavita012715
Chemical formula C 24H 12F 6N 2O 3
Formula weight 490.36 g/mol
Temperature 100(2) K
Wavelength 0.71073 Å
Crystal size 0.102 x 0.133 x 0.471 mm
Crystal habit clear orange prism
Crystal system triclinic
Space group P -1
Unit cell dimensions a = 7.9032(8) Å α = 93.280(2) °
b = 8.8144(10) Å β = 95.688(2) °
c = 14.8800(16) Å γ = 90.365(2) °
Volume 1029.70(19) Å
3

Z 2
Density (calculated) 1.582 g/cm
3

Absorption coefficient 0.142 mm
-1

F(000) 496

Table 3: Data collection and structure refinement for 5h
Diffractometer Bruker APEX DUO
Radiation source fine-focus tube, MoK α
Theta range for data collection 2.31 to 30.52 °
172

Index ranges -11<=h<=11, -12<=k<=12, -21<=l<=20
Reflections collected 25775
Independent reflections 6216 [R(int) = 0.0327]
Coverage of independent
reflections
98.8%
Absorption correction multi-scan
Max. and min. transmission 0.9860 and 0.9360
Structure solution technique direct methods
Structure solution program SHELXTL XT 2013/1 (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 6216 / 0 / 316
Goodness-of-fit on F
2
1.040
Final R indices
4814 data; I>2 σ
(I)
R1 = 0.0458, wR2 =
0.1186
all data
R1 = 0.0631, wR2 =
0.1291
Weighting scheme
w=1/[ σ
2
(F o
2
)+(0.0622P)
2
+0.5308P]
where P=(F o
2
+2F c
2
)/3
Largest diff. peak and hole 0.668 and -0.358 eÅ
-3

R.M.S. deviation from mean 0.061 eÅ
-3

Table 4: Atomic coordinates and equivalent
isotropic atomic displacement parameters (Å
2
) for
5h
U(eq) is defined as one third of the trace of the orthogonalized
Uij tensor.
173

x/a y/b z/c U(eq)
C1 0.53012(17) 0.53261(15) 0.19004(9) 0.0152(2)
C2 0.44140(17) 0.43939(15) 0.11975(9) 0.0159(2)
C3 0.26714(18) 0.45889(16) 0.08836(10) 0.0205(3)
C4 0.1920(2) 0.36443(17) 0.01891(11) 0.0238(3)
C5 0.2845(2) 0.24893(17) 0.97757(10) 0.0233(3)
C6 0.4509(2) 0.22621(17) 0.00738(10) 0.0205(3)
C7 0.53364(18) 0.31981(15) 0.07951(9) 0.0167(3)
C8 0.70552(19) 0.29625(17) 0.11198(10) 0.0215(3)
C9 0.78488(18) 0.38559(17) 0.18194(10) 0.0214(3)
C10 0.69758(17) 0.50788(16) 0.22230(9) 0.0167(3)
C11 0.78521(17) 0.61145(17) 0.29505(10) 0.0198(3)
C12 0.9146(2) 0.53956(19) 0.36516(11) 0.0257(3)
C13 0.32515(16) 0.77352(15) 0.35295(9) 0.0144(2)
C14 0.37389(17) 0.79053(15) 0.44833(9) 0.0160(3)
C15 0.49367(18) 0.69390(16) 0.49327(10) 0.0194(3)
C16 0.5346(2) 0.71280(18) 0.58526(10) 0.0237(3)
C17 0.4593(2) 0.8292(2) 0.63635(10) 0.0266(3)
C18 0.3465(2) 0.92601(18) 0.59482(10) 0.0240(3)
C19 0.30070(18) 0.90988(16) 0.49966(10) 0.0187(3)
C20 0.18530(19) 0.01014(17) 0.45555(10) 0.0211(3)
C21 0.13883(18) 0.99098(16) 0.36436(10) 0.0199(3)
C22 0.20707(17) 0.87106(15) 0.31235(9) 0.0158(2)
C23 0.13452(17) 0.84393(16) 0.21638(10) 0.0171(3)
C24 0.14134(19) 0.97731(17) 0.15348(10) 0.0226(3)
F1 0.05730(12) 0.49562(12) 0.33059(8) 0.0349(2)
174

x/a y/b z/c U(eq)
F2 0.84635(15) 0.41673(15) 0.39616(8) 0.0467(3)
F3 0.95858(15) 0.63866(14) 0.43416(8) 0.0422(3)
F4 0.14292(13) 0.92722(11) 0.06758(6) 0.0300(2)
F5 0.99952(14) 0.06014(12) 0.15874(8) 0.0366(3)
F6 0.27369(13) 0.07041(11) 0.17531(7) 0.0306(2)
N1 0.43768(14) 0.66092(13) 0.22885(8) 0.0154(2)
N2 0.40146(14) 0.64777(13) 0.30934(8) 0.0160(2)
O1 0.40717(13) 0.77133(11) 0.17933(7) 0.0192(2)
O2 0.75857(14) 0.74555(13) 0.30523(9) 0.0283(3)
O3 0.05323(13) 0.73188(12) 0.18730(7) 0.0215(2)

Table 5: Bond lengths (Å) for 5h
C1-C10 1.3853(18) C1-C2 1.4177(19)
C1-N1 1.4717(17) C2-C7 1.4230(19)
C2-C3 1.4245(19) C3-C4 1.374(2)
C3-H3 0.95 C4-C5 1.406(2)
C4-H4 0.95 C5-C6 1.366(2)
C5-H5 0.95 C6-C7 1.419(2)
C6-H6 0.95 C7-C8 1.417(2)
C8-C9 1.367(2) C8-H8 0.95
C9-C10 1.4198(19) C9-H9 0.95
C10-C11 1.488(2) C11-O2 1.2056(19)
C11-C12 1.552(2) C12-F3 1.3269(19)
C12-F2 1.3323(19) C12-F1 1.336(2)
C13-C22 1.3903(19) C13-N2 1.4203(17)
175

C13-C14 1.4323(18) C14-C15 1.421(2)
C14-C19 1.4242(19) C15-C16 1.375(2)
C15-H15 0.95 C16-C17 1.411(2)
C16-H16 0.95 C17-C18 1.366(2)
C17-H17 0.95 C18-C19 1.425(2)
C18-H18 0.95 C19-C20 1.415(2)
C20-C21 1.371(2) C20-H20 0.95
C21-C22 1.4155(19) C21-H21 0.95
C22-C23 1.4907(19) C23-O3 1.2097(18)
C23-C24 1.548(2) C24-F6 1.3282(18)
C24-F4 1.3296(18) C24-F5 1.3479(18)
N1-O1 1.2642(15) N1-N2 1.2701(16)

Table 6: Bond angles (°) for 5h
C10-C1-C2 122.83(12) C10-C1-N1 119.75(12)
C2-C1-N1 117.42(11) C1-C2-C7 117.23(12)
C1-C2-C3 123.67(12) C7-C2-C3 119.10(12)
C4-C3-C2 119.71(13) C4-C3-H3 120.1
C2-C3-H3 120.1 C3-C4-C5 121.14(14)
C3-C4-H4 119.4 C5-C4-H4 119.4
C6-C5-C4 120.31(14) C6-C5-H5 119.8
C4-C5-H5 119.8 C5-C6-C7 120.63(13)
C5-C6-H6 119.7 C7-C6-H6 119.7
C8-C7-C6 121.26(13) C8-C7-C2 119.66(12)
C6-C7-C2 119.07(12) C9-C8-C7 121.30(13)
C9-C8-H8 119.4 C7-C8-H8 119.4
176

C8-C9-C10 120.44(13) C8-C9-H9 119.8
C10-C9-H9 119.8 C1-C10-C9 118.48(12)
C1-C10-C11 120.42(12) C9-C10-C11 121.06(12)
O2-C11-C10 124.81(13) O2-C11-C12 117.83(13)
C10-C11-C12 117.30(13) F3-C12-F2 108.97(14)
F3-C12-F1 107.35(12) F2-C12-F1 107.01(14)
F3-C12-C11 110.28(14) F2-C12-C11 110.11(12)
F1-C12-C11 112.98(13) C22-C13-N2 126.12(12)
C22-C13-C14 120.12(12) N2-C13-C14 113.68(11)
C15-C14-C19 118.92(12) C15-C14-C13 122.45(12)
C19-C14-C13 118.62(13) C16-C15-C14 120.46(14)
C16-C15-H15 119.8 C14-C15-H15 119.8
C15-C16-C17 120.54(15) C15-C16-H16 119.7
C17-C16-H16 119.7 C18-C17-C16 120.38(14)
C18-C17-H17 119.8 C16-C17-H17 119.8
C17-C18-C19 120.72(14) C17-C18-H18 119.6
C19-C18-H18 119.6 C20-C19-C14 119.68(13)
C20-C19-C18 121.38(13) C14-C19-C18 118.94(14)
C21-C20-C19 120.81(13) C21-C20-H20 119.6
C19-C20-H20 119.6 C20-C21-C22 120.45(13)
C20-C21-H21 119.8 C22-C21-H21 119.8
C13-C22-C21 120.26(13) C13-C22-C23 121.71(12)
C21-C22-C23 117.71(12) O3-C23-C22 124.29(13)
O3-C23-C24 117.57(13) C22-C23-C24 117.53(12)
F6-C24-F4 108.53(13) F6-C24-F5 107.42(13)
F4-C24-F5 107.08(12) F6-C24-C23 113.70(12)
177

F4-C24-C23 111.32(12) F5-C24-C23 108.51(13)
O1-N1-N2 128.00(12) O1-N1-C1 116.62(11)
N2-N1-C1 115.36(11) N1-N2-C13 117.80(11)

Table 7: Torsion angles (°) for 5h.
C10-C1-C2-C7 -2.5(2) N1-C1-C2-C7 177.12(12)
C10-C1-C2-C3 177.15(14) N1-C1-C2-C3 -3.2(2)
C1-C2-C3-C4 179.07(14) C7-C2-C3-C4 -1.3(2)
C2-C3-C4-C5 -0.4(2) C3-C4-C5-C6 1.5(2)
C4-C5-C6-C7 -0.9(2) C5-C6-C7-C8 179.12(14)
C5-C6-C7-C2 -0.9(2) C1-C2-C7-C8 1.61(19)
C3-C2-C7-C8 -178.06(14) C1-C2-C7-C6 -178.42(13)
C3-C2-C7-C6 1.9(2) C6-C7-C8-C9 -179.47(14)
C2-C7-C8-C9 0.5(2) C7-C8-C9-C10 -1.8(2)
C2-C1-C10-C9 1.2(2) N1-C1-C10-C9 -178.38(12)
C2-C1-C10-C11 178.79(13) N1-C1-C10-C11 -0.8(2)
C8-C9-C10-C1 1.0(2) C8-C9-C10-C11 -176.55(14)
C1-C10-C11-O2 -32.5(2) C9-C10-C11-O2 144.97(16)
C1-C10-C11-C12 144.72(14) C9-C10-C11-C12 -37.80(19)
O2-C11-C12-F3 8.7(2) C10-C11-C12-F3 -168.70(13)
O2-C11-C12-F2 129.03(16) C10-C11-C12-F2 -48.41(19)
O2-C11-C12-F1 -111.40(16) C10-C11-C12-F1 71.17(17)
C22-C13-C14-C15 179.89(12) N2-C13-C14-C15 2.78(18)
C22-C13-C14-C19 -0.80(19) N2-C13-C14-C19 -177.91(11)
C19-C14-C15-C16 1.8(2) C13-C14-C15-C16 -178.90(13)
C14-C15-C16-C17 -0.5(2) C15-C16-C17-C18 -1.0(2)
178

C16-C17-C18-C19 1.1(2) C15-C14-C19-C20 178.01(13)
C13-C14-C19-C20 -1.33(19) C15-C14-C19-C18 -1.66(19)
C13-C14-C19-C18 179.01(12) C17-C18-C19-C20 -179.41(14)
C17-C18-C19-C14 0.2(2) C14-C19-C20-C21 2.1(2)
C18-C19-C20-C21 -178.27(13) C19-C20-C21-C22 -0.7(2)
N2-C13-C22-C21 178.95(13) C14-C13-C22-C21 2.2(2)
N2-C13-C22-C23 5.6(2) C14-C13-C22-C23 -171.11(12)
C20-C21-C22-C13 -1.5(2) C20-C21-C22-C23 172.08(13)
C13-C22-C23-O3 60.62(19) C21-C22-C23-O3 -112.87(16)
C13-C22-C23-C24 -128.61(14) C21-C22-C23-C24 57.89(17)
O3-C23-C24-F6 -158.09(13) C22-C23-C24-F6 30.51(18)
O3-C23-C24-F4 -35.14(18) C22-C23-C24-F4 153.46(12)
O3-C23-C24-F5 82.45(16) C22-C23-C24-F5 -88.95(15)
C10-C1-N1-O1 108.53(14) C2-C1-N1-O1 -71.12(16)
C10-C1-N1-N2 -70.07(16) C2-C1-N1-N2 110.28(14)
O1-N1-N2-C13 -3.63(19) C1-N1-N2-C13 174.78(11)
C22-C13-N2-N1 36.83(19) C14-C13-N2-N1 -146.26(12)

Table 8: Anisotropic atomic displacement parameters (Å
2
) for 5h
The anisotropic atomic displacement factor exponent takes the form: -2 π
2
[ h
2
a
*2
U11 + ...
+ 2 h k a
*
b
*
U12 ]
U 11 U 22 U 33 U 23 U 13 U 12
C1 0.0135(6) 0.0162(6) 0.0158(6) -0.0010(4) 0.0021(5) 0.0023(4)
C2 0.0147(6) 0.0160(6) 0.0166(6) 0.0008(5) 0.0001(5) 0.0024(5)
C3 0.0164(6) 0.0202(7) 0.0236(7) -0.0021(5) -0.0022(5) 0.0036(5)
C4 0.0194(7) 0.0234(7) 0.0268(7) -0.0005(6) -0.0066(6) 0.0013(5)
179

U 11 U 22 U 33 U 23 U 13 U 12
C5 0.0284(8) 0.0215(7) 0.0186(7) -0.0003(5) -0.0041(6) -0.0012(6)
C6 0.0259(7) 0.0194(7) 0.0159(6) -0.0013(5) 0.0023(5) 0.0021(5)
C7 0.0186(6) 0.0174(6) 0.0140(6) 0.0014(5) 0.0015(5) 0.0031(5)
C8 0.0184(6) 0.0228(7) 0.0231(7) -0.0025(5) 0.0023(5) 0.0079(5)
C9 0.0146(6) 0.0247(7) 0.0241(7) 0.0002(5) -0.0014(5) 0.0070(5)
C10 0.0141(6) 0.0202(6) 0.0154(6) 0.0002(5) -0.0001(5) 0.0013(5)
C11 0.0113(6) 0.0271(7) 0.0208(7) -0.0004(5) 0.0015(5) -0.0019(5)
C12 0.0205(7) 0.0293(8) 0.0258(8) 0.0043(6) -0.0062(6) -0.0081(6)
C13 0.0117(5) 0.0154(6) 0.0157(6) -0.0018(4) 0.0020(4) -0.0019(4)
C14 0.0146(6) 0.0174(6) 0.0158(6) -0.0016(5) 0.0023(5) -0.0061(5)
C15 0.0186(6) 0.0198(6) 0.0191(6) 0.0006(5) -0.0006(5) -0.0057(5)
C16 0.0244(7) 0.0270(8) 0.0188(7) 0.0038(6) -0.0031(5) -0.0094(6)
C17 0.0303(8) 0.0337(8) 0.0151(6) -0.0020(6) 0.0011(6) -0.0159(6)
C18 0.0273(7) 0.0261(7) 0.0187(7) -0.0062(5) 0.0076(6) -0.0121(6)
C19 0.0182(6) 0.0185(6) 0.0195(6) -0.0037(5) 0.0062(5) -0.0082(5)
C20 0.0197(6) 0.0192(7) 0.0251(7) -0.0056(5) 0.0097(5) -0.0039(5)
C21 0.0164(6) 0.0172(6) 0.0265(7) -0.0016(5) 0.0054(5) 0.0007(5)
C22 0.0125(6) 0.0168(6) 0.0181(6) -0.0012(5) 0.0023(5) -0.0015(5)
C23 0.0108(5) 0.0202(6) 0.0202(6) -0.0007(5) 0.0013(5) 0.0045(5)
C24 0.0210(7) 0.0234(7) 0.0222(7) 0.0017(5) -0.0042(5) 0.0055(5)
F1 0.0191(5) 0.0353(6) 0.0484(6) 0.0083(5) -0.0093(4) 0.0037(4)
F2 0.0430(6) 0.0575(8) 0.0376(6) 0.0265(5) -0.0180(5) -0.0289(6)
F3 0.0387(6) 0.0499(7) 0.0326(6) -0.0070(5) -0.0178(5) -0.0049(5)
F4 0.0383(6) 0.0323(5) 0.0184(4) 0.0033(4) -0.0043(4) 0.0055(4)
F5 0.0343(6) 0.0338(5) 0.0411(6) 0.0053(4) -0.0027(5) 0.0203(4)
180

U 11 U 22 U 33 U 23 U 13 U 12
F6 0.0350(5) 0.0258(5) 0.0297(5) 0.0087(4) -0.0066(4) -0.0067(4)
N1 0.0114(5) 0.0173(5) 0.0170(5) 0.0010(4) -0.0006(4) 0.0011(4)
N2 0.0133(5) 0.0192(5) 0.0151(5) -0.0015(4) 0.0006(4) -0.0001(4)
O1 0.0214(5) 0.0176(5) 0.0196(5) 0.0055(4) 0.0043(4) 0.0048(4)
O2 0.0176(5) 0.0272(6) 0.0382(7) -0.0095(5) 0.0001(4) 0.0009(4)
O3 0.0146(5) 0.0242(5) 0.0244(5) -0.0037(4) -0.0016(4) 0.0000(4)

Table 9: Hydrogen atomic coordinates and
isotropic atomic displacement parameters
(Å
2
) for 5h
x/a y/b z/c U(eq)
H3 0.2031 0.5369 0.1153 0.025
H4 0.0756 0.3774 -0.0015 0.029
H5 0.2310 0.1864 -0.0713 0.028
H6 0.5119 0.1470 -0.0205 0.025
H8 0.7668 0.2168 0.0846 0.026
H9 0.8992 0.3657 0.2037 0.026
H15 0.5459 0.6157 0.4595 0.023
H16 0.6141 0.6470 0.6147 0.028
H17 0.4872 0.8402 0.7000 0.032
H18 0.2981 1.0050 0.6298 0.029
H20 0.1395 1.0917 0.4895 0.025
H21 0.0603 1.0587 0.3359 0.024

181

Crystal Structure Report for 6e

A clear orange prism-like specimen of C8H4F3NO3, approximate dimensions 0.127 mm
x 0.161 mm x 0.338 mm, was used for the X-ray crystallographic analysis. The X-ray intensity
data were measured on a Bruker APEX DUO system equipped with a TRIUMPH curved-crystal
monochromator and a MoKα fine-focus tube (λ = 0.71073 Å).
Table 1: Data collection details for 6e
Axis dx/mm 2 θ/ ° ω/ ° φ/ ° χ/ ° Width/ ° Frames Time/s Wavelength/Å Voltage/kV Current/mA Temperature/K
Omega 50.446 30.00 30.00 0.00 54.73 0.50 360 10.00 0.71073 50 30.0 100
Omega 50.446 30.00 30.00 72.00 54.73 0.50 360 10.00 0.71073 50 30.0 100
Omega 50.446 30.00 30.00 144.00 54.73 0.50 360 10.00 0.71073 50 30.0 100
Omega 50.446 30.00 30.00 216.00 54.73 0.50 360 10.00 0.71073 50 30.0 100
Omega 50.446 30.00 30.00 288.00 54.73 0.50 360 10.00 0.71073 50 30.0 100
Phi 50.446 30.00 0.00 0.00 54.73 0.50 720 10.00 0.71073 50 30.0 100

A total of 2520 frames were collected. The total exposure time was 7.00 hours. The frames were
integrated with the Bruker SAINT software package using a SAINT V8.34A (Bruker AXS, 2013)
algorithm. The integration of the data using a monoclinic unit cell yielded a total
182

of 19479 reflections to a maximum θ angle of 30.65° (0.70 Å resolution), of which 2527 were
independent (average redundancy 7.708, completeness = 99.1%, Rint = 3.65%, Rsig = 2.12%)
and 2114 (83.66%) were greater than 2σ(F
2
). The final cell constants
of a = 6.4041(11) Å, b = 16.548(3) Å, c = 8.0820(14) Å, β = 105.719(2)°, volume = 824.5(2) Å
3
,
are based upon the refinement of the XYZ-centroids of 98 reflections above 20 σ(I) with 5.810° <
2θ < 53.05°. Data were corrected for absorption effects using the multi-scan method (SADABS).
The ratio of minimum to maximum apparent transmission was 0.858. The calculated minimum
and maximum transmission coefficients (based on crystal size) are 0.9420 and 0.9780.

The structure was solved and refined using the Bruker SHELXTL Software Package, using the
space group P 1 21/c 1, with Z = 4 for the formula unit, C8H4F3NO3. The final anisotropic full-
matrix least-squares refinement on F
2
with 139 variables converged at R1 = 3.75%, for the
observed data and wR2 = 10.35% for all data. The goodness-of-fit was 1.030. The largest peak in
the final difference electron density synthesis was 0.557 e
-
/Å
3
and the largest hole was -0.248 e
-
/Å
3
with an RMS deviation of 0.062 e
-
/Å
3
. On the basis of the final model, the calculated density
was 1.765 g/cm
3
and F(000), 440 e
-
.
Table 2: Sample and crystal data for 6e
Identification code Kavita051016
Chemical formula C 8H 4F 3NO 3
Formula weight 219.12 g/mol
Temperature 100(2) K
Wavelength 0.71073 Å
Crystal size 0.127 x 0.161 x 0.338 mm
183

Crystal habit clear orange prism
Crystal system monoclinic
Space group P 1 21/c 1
Unit cell dimensions a = 6.4041(11) Å α = 90 °
b = 16.548(3) Å β = 105.719(2) °
c = 8.0820(14) Å γ = 90 °
Volume 824.5(2) Å
3

Z 4
Density (calculated) 1.765 g/cm
3

Absorption coefficient 0.178 mm
-1

F(000) 440

Table 3: Data collection and structure refinement for 6e
Diffractometer Bruker APEX DUO
Radiation source fine-focus tube, MoK α
Theta range for data collection 2.46 to 30.65 °
Index ranges -8<=h<=9, -23<=k<=23, -11<=l<=11
Reflections collected 19479
Independent reflections 2527 [R(int) = 0.0365]
Coverage of independent
reflections
99.1%
Absorption correction multi-scan
Max. and min. transmission 0.9780 and 0.9420
Structure solution technique direct methods
Structure solution program SHELXTL XT 2013/1 (Bruker AXS, 2014)
Refinement method Full-matrix least-squares on F
2

184

Refinement program SHELXTL XL 2014/7 (Bruker AXS, 2014)
Function minimized Σ w(F o
2
- F c
2
)
2

Data / restraints / parameters 2527 / 0 / 139
Goodness-of-fit on F
2
1.030
Final R indices
2114 data; I>2 σ
(I)
R1 = 0.0375, wR2 =
0.0967
all data
R1 = 0.0472, wR2 =
0.1035
Weighting scheme
w=1/[ σ
2
(F o
2
)+(0.0579P)
2
+0.3014P]
where P=(F o
2
+2F c
2
)/3
Largest diff. peak and hole 0.557 and -0.248 eÅ
-3

R.M.S. deviation from mean 0.062 eÅ
-3

Table 4: Atomic coordinates and equivalent
isotropic atomic displacement parameters (Å
2
) for
6e
U(eq) is defined as one third of the trace of the orthogonalized
Uij tensor.
x/a y/b z/c U(eq)
C1 0.64806(17) 0.39665(6) 0.67385(13) 0.0128(2)
C2 0.76050(18) 0.43304(7) 0.57684(13) 0.0148(2)
C3 0.67309(18) 0.42840(6) 0.38784(13) 0.0136(2)
C4 0.47192(18) 0.38204(7) 0.31506(14) 0.0158(2)
C5 0.36228(18) 0.34617(7) 0.41579(14) 0.0161(2)
C6 0.44796(17) 0.35367(6) 0.59971(14) 0.0139(2)
C7 0.68106(17) 0.39086(6) 0.86513(13) 0.0130(2)
C8 0.87494(19) 0.33676(7) 0.95286(14) 0.0175(2)
N1 0.35822(16) 0.32520(6) 0.71450(13) 0.0178(2)
185

x/a y/b z/c U(eq)
O1 0.48890(13) 0.34569(5) 0.87856(10) 0.01791(18)
O2 0.69447(14) 0.46519(5) 0.94113(10) 0.01714(18)
O3 0.76742(14) 0.46356(5) 0.29363(10) 0.01853(18)
F1 0.88861(13) 0.32745(5) 0.11992(9) 0.0272(2)
F2 0.06001(12) 0.36928(5) 0.94041(10) 0.02771(19)
F3 0.85718(14) 0.26327(5) 0.88176(10) 0.0282(2)

Table 5: Bond lengths (Å) for 6e
C1-C2 1.3422(15) C1-C6 1.4460(15)
C1-C7 1.5056(14) C2-C3 1.4796(14)
C2-H2 0.95 C3-O3 1.2380(13)
C3-C4 1.4777(15) C4-C5 1.3483(16)
C4-H4 0.95 C5-C6 1.4436(15)
C5-H5 0.95 C6-N1 1.3046(15)
C7-O2 1.3671(13) C7-O1 1.4688(13)
C7-C8 1.5391(16) C8-F2 1.3300(14)
C8-F3 1.3367(14) C8-F1 1.3381(13)
N1-O1 1.4043(12) O2-H2O 0.822(18)

Table 6: Bond angles (°) for 6e
C2-C1-C6 122.28(10) C2-C1-C7 132.84(10)
C6-C1-C7 104.85(9) C1-C2-C3 117.84(10)
C1-C2-H2 121.1 C3-C2-H2 121.1
O3-C3-C4 121.15(10) O3-C3-C2 119.96(10)
186

C4-C3-C2 118.89(9) C5-C4-C3 121.92(10)
C5-C4-H4 119.0 C3-C4-H4 119.0
C4-C5-C6 117.97(10) C4-C5-H5 121.0
C6-C5-H5 121.0 N1-C6-C5 125.69(10)
N1-C6-C1 113.24(10) C5-C6-C1 121.06(10)
O2-C7-O1 112.12(9) O2-C7-C1 112.23(9)
O1-C7-C1 102.76(8) O2-C7-C8 111.82(9)
O1-C7-C8 104.92(9) C1-C7-C8 112.42(9)
F2-C8-F3 108.02(10) F2-C8-F1 107.88(10)
F3-C8-F1 107.68(10) F2-C8-C7 110.73(10)
F3-C8-C7 111.54(9) F1-C8-C7 110.85(9)
C6-N1-O1 108.64(9) N1-O1-C7 110.49(8)
C7-O2-H2O 110.3(12)

Table 7: Torsion angles (°) for 6e
C6-C1-C2-C3 0.19(16) C7-C1-C2-C3 -177.69(11)
C1-C2-C3-O3 177.40(11) C1-C2-C3-C4 -2.03(15)
O3-C3-C4-C5 -177.22(11) C2-C3-C4-C5 2.20(16)
C3-C4-C5-C6 -0.43(17) C4-C5-C6-N1 177.45(11)
C4-C5-C6-C1 -1.48(16) C2-C1-C6-N1 -177.42(11)
C7-C1-C6-N1 0.97(12) C2-C1-C6-C5 1.64(17)
C7-C1-C6-C5 -179.97(10) C2-C1-C7-O2 56.28(16)
C6-C1-C7-O2 -121.87(10) C2-C1-C7-O1 176.92(12)
C6-C1-C7-O1 -1.23(10) C2-C1-C7-C8 -70.81(16)
C6-C1-C7-C8 111.04(10) O2-C7-C8-F2 -61.79(12)
O1-C7-C8-F2 176.44(8) C1-C7-C8-F2 65.51(12)
187

O2-C7-C8-F3 177.87(9) O1-C7-C8-F3 56.11(11)
C1-C7-C8-F3 -54.82(13) O2-C7-C8-F1 57.90(12)
O1-C7-C8-F1 -63.86(11) C1-C7-C8-F1 -174.79(9)
C5-C6-N1-O1 -179.24(10) C1-C6-N1-O1 -0.24(13)
C6-N1-O1-C7 -0.64(12) O2-C7-O1-N1 121.89(9)
C1-C7-O1-N1 1.17(11) C8-C7-O1-N1 -116.54(9)

Table 8: Anisotropic atomic displacement parameters (Å
2
) for
6e
The anisotropic atomic displacement factor exponent takes the
form: -2π
2
[ h
2
a
*2
U11 + ... + 2 h k a
*
b
*
U12 ]
U 11 U 22 U 33 U 23 U 13 U 12
C1 0.0143(5) 0.0138(4) 0.0100(4) -0.0011(3) 0.0029(3) -0.0002(4)
C2 0.0158(5) 0.0177(5) 0.0106(4) -0.0016(4) 0.0029(4) -0.0026(4)
C3 0.0168(5) 0.0137(4) 0.0105(4) -0.0008(3) 0.0040(4) 0.0003(4)
C4 0.0183(5) 0.0158(5) 0.0115(4) -0.0017(4) 0.0008(4) -0.0011(4)
C5 0.0163(5) 0.0155(5) 0.0142(5) -0.0014(4) 0.0003(4) -0.0021(4)
C6 0.0142(5) 0.0133(4) 0.0140(5) -0.0006(4) 0.0033(4) -0.0005(4)
C7 0.0147(4) 0.0148(5) 0.0102(4) -0.0001(3) 0.0042(3) -0.0013(4)
C8 0.0193(5) 0.0204(5) 0.0125(5) -0.0006(4) 0.0037(4) 0.0027(4)
N1 0.0168(4) 0.0209(5) 0.0149(4) 0.0002(3) 0.0030(3) -0.0035(4)
O1 0.0171(4) 0.0253(4) 0.0118(4) 0.0011(3) 0.0048(3) -0.0046(3)
O2 0.0262(4) 0.0157(4) 0.0102(3) -0.0011(3) 0.0059(3) 0.0004(3)
O3 0.0227(4) 0.0219(4) 0.0120(4) 0.0000(3) 0.0063(3) -0.0045(3)
F1 0.0344(4) 0.0341(4) 0.0122(3) 0.0060(3) 0.0048(3) 0.0129(3)
F2 0.0143(3) 0.0405(5) 0.0272(4) -0.0001(3) 0.0036(3) 0.0006(3)
188

U 11 U 22 U 33 U 23 U 13 U 12
F3 0.0353(4) 0.0196(4) 0.0275(4) -0.0047(3) 0.0045(3) 0.0088(3)

Table 9: Hydrogen atomic coordinates and
isotropic atomic displacement parameters
(Å
2
) for 6e
x/a y/b z/c U(eq)
H2 0.8919 0.4609 0.6279 0.018
H4 0.4183 0.3774 0.1938 0.019
H5 0.2326 0.3169 0.3672 0.019
H2O 0.709(3) 0.4604(10) 1.045(2) 0.021

Crystal Structure Report for 8d

189

A clear colourless prism-like specimen of C12H17BrF3NO5S2, approximate dimensions 0.190 mm
x 0.280 mm x 0.350 mm, was used for the X-ray crystallographic analysis. The X-ray intensity
data were measured on a Bruker APEX DUO system equipped with a fine-focus tube (MoKα , λ
= 0.71073 Å)and a TRIUMPH curved-crystal monochromator.
The total exposure time was 7.00 hours. The frames were integrated with the Bruker SAINT
software package using a SAINT V8.38A (Bruker AXS, 2013) algorithm. The integration of the
data using a triclinic unit cell yielded a total of 19993 reflections to a maximum θ angle of 30.57°
(0.70 Å resolution), of which 5356 were independent (average redundancy 3.733, completeness
= 98.0%, Rint = 2.58%, Rsig = 2.12%) and 4825 (90.09%) were greater than 2σ(F
2
).The final cell
constants of a = 9.414(3) Å, b = 9.426(3) Å, c = 11.441(4) Å, α = 112.364(4)°, β = 98.218(4)°, γ
= 101.891(4)°, volume = 890.8(5) Å
3
, are based upon the refinement of the XYZ-centroids
of 9921 reflections above 20 σ(I) with 4.56° < 2θ < 61.08°. Data were corrected for absorption
effects using the multi-scan method (SADABS). The ratio of minimum to maximum apparent
transmission was 0.847.
The structure was solved and refined using the Bruker SHELXTL Software Package, using the
space group P -1, with Z = 2 for the formula unit, C12H17BrF3NO5S2. The final anisotropic full-
matrix least-squares refinement on F
2
with 248 variables converged at R1 = 2.27%, for the
observed data and wR2 = 5.42% for all data. The goodness-of-fit was 1.063. The largest peak in
the final difference electron density synthesis was 0.507 e
-
/Å
3
and the largest hole was -0.508 e
-
/Å
3
with an RMS deviation of 0.061 e
-
/Å
3
. On the basis of the final model, the calculated density
was 1.701 g/cm
3
andF(000), 460 e
-
.

190

Table 1: Sample and crystal data for 8d
Identification code Kavita062518
Chemical formula C 12H 17BrF 3NO 5S 2
Formula weight 456.29 g/mol
Temperature 100(2) K
Wavelength 0.71073 Å
Crystal size 0.190 x 0.280 x 0.350 mm
Crystal habit clear colourless prism
Crystal system triclinic
Space group P -1
Unit cell dimensions a = 9.414(3) Å α = 112.364(4) °
b = 9.426(3) Å β = 98.218(4) °
c = 11.441(4) Å γ = 101.891(4) °
Volume 890.8(5) Å
3

Z 2
Density (calculated) 1.701 g/cm
3

Absorption coefficient 2.593 mm
-1

F(000) 460

Table 2: Data collection and structure refinement for 8d
Diffractometer Bruker APEX DUO
Radiation source fine-focus tube (MoK α , λ = 0.71073 Å)
Theta range for data
collection
1.99 to 30.57 °
Index ranges -13<=h<=13, -13<=k<=13, -16<=l<=16
Reflections collected 19993
191

Independent reflections 5356 [R(int) = 0.0258]
Coverage of independent
reflections
98.0%
Absorption correction multi-scan
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 2017/1 (Bruker AXS,
2017)
Function minimized Σ w(Fo
2
- Fc
2
)
2

Data / restraints /
parameters
5356 / 0 / 248
Goodness-of-fit on F
2
1.063
Δ/σmax 0.001
Final R indices
4825 data;
I>2σ(I)
R1 = 0.0227, wR2 =
0.0519
all data
R1 = 0.0278, wR2 =
0.0542
Weighting scheme
w=1/[σ
2
(Fo
2
)+(0.0186P)
2
+0.5577P]
where P=(Fo
2
+2Fc
2
)/3
Largest diff. peak and hole 0.507 and -0.508 eÅ
-3

R.M.S. deviation from
mean
0.061 eÅ
-3

192

Table 3: Atomic coordinates and equivalent isotropic
atomic displacement parameters (Å
2
) for 8d
U(eq) is defined as one third of the trace of the
orthogonalized Uij tensor.
x/a y/b z/c U(eq)
C1 0.37680(13) 0.43844(15) 0.59393(12) 0.0122(2)
C2 0.24927(14) 0.31536(15) 0.51364(12) 0.0144(2)
C3 0.16931(14) 0.22177(15) 0.56431(12) 0.0151(2)
C4 0.22083(14) 0.25232(15) 0.69370(12) 0.0143(2)
C5 0.34603(14) 0.37767(15) 0.77532(12) 0.0139(2)
C6 0.42667(13) 0.47472(14) 0.72579(11) 0.0121(2)
C7 0.56352(14) 0.61283(15) 0.81948(12) 0.0129(2)
C8 0.51039(15) 0.75592(16) 0.90065(13) 0.0177(2)
N1 0.45086(12) 0.52826(12) 0.53001(10) 0.01210(19)
O1 0.40921(11) 0.64394(11) 0.52074(9) 0.01746(18)
O2 0.65158(11) 0.65940(12) 0.74552(9) 0.01615(18)
O3 0.63994(11) 0.57476(12) 0.91152(9) 0.01610(18)
F1 0.42226(10) 0.79660(10) 0.82348(9) 0.02349(18)
F2 0.62662(10) 0.88450(10) 0.97369(8) 0.02462(18)
F3 0.43180(11) 0.72414(11) 0.98136(8) 0.02618(19)
Br1 0.11978(2) 0.11262(2) 0.75805(2) 0.01982(4)
S1 0.63696(4) 0.17830(4) 0.67778(4) 0.02175(7)
C9 0.6481(2) 0.01866(19) 0.72362(18) 0.0327(4)
C10 0.74114(18) 0.1346(2) 0.55664(15) 0.0264(3)
O4 0.73730(12) 0.32907(12) 0.79100(11) 0.0251(2)
S2 0.06785(4) 0.78759(4) 0.84587(4) 0.02362(8)
193

x/a y/b z/c U(eq)
C11 0.0331(6) 0.6657(13) 0.9414(8) 0.0316(15)
C12 0.0621(10) 0.6305(12) 0.7026(6) 0.0346(15)
C11A 0.0554(6) 0.7462(13) 0.9764(6) 0.0351(14)
C12A 0.0248(8) 0.5872(8) 0.7174(7) 0.0364(13)
O5 0.93106(12) 0.84287(13) 0.82096(12) 0.0266(2)

Table 4: Bond lengths (Å) for 8d
C1-C2 1.3895(17) C1-C6 1.3972(17)
C1-N1 1.4531(16) C2-C3 1.3861(18)
C2-H2 0.95 C3-C4 1.3864(18)
C3-H3 0.95 C4-C5 1.3889(18)
C4-Br1 1.8982(13) C5-C6 1.4020(17)
C5-H5 0.95 C6-C7 1.5348(17)
C7-O2 1.3890(15) C7-O3 1.3901(15)
C7-C8 1.5458(18) C8-F2 1.3364(15)
C8-F1 1.3395(16) C8-F3 1.3432(16)
N1-O1 1.2674(14) N1-N1 1.311(2)
O2-H2A 0.78(2) O3-H3A 0.84(2)
S1-O4 1.5120(11) S1-C10 1.7813(16)
S1-C9 1.7888(17) C9-H9A 0.98
C9-H9B 0.98 C9-H9C 0.98
C10-H10A 0.98 C10-H10B 0.98
C10-H10C 0.98 S2-O5 1.5152(12)
S2-C11A 1.694(4) S2-C12 1.725(7)
S2-C12A 1.815(6) S2-C11 1.877(6)
194

C11-H11A 0.98 C11-H11B 0.98
C11-H11C 0.98 C12-H12A 0.98
C12-H12B 0.98 C12-H12C 0.98
C11A-H11D 0.98 C11A-H11E 0.98
C11A-H11F 0.98 C12A-H12D 0.98
C12A-H12E 0.98 C12A-H12F 0.98

Table 5: Bond angles (°) for 8d
C2-C1-C6 122.51(11) C2-C1-N1 114.35(11)
C6-C1-N1 123.13(11) C3-C2-C1 119.38(11)
C3-C2-H2 120.3 C1-C2-H2 120.3
C2-C3-C4 118.75(12) C2-C3-H3 120.6
C4-C3-H3 120.6 C3-C4-C5 122.14(11)
C3-C4-Br1 118.32(10) C5-C4-Br1 119.50(9)
C4-C5-C6 119.65(11) C4-C5-H5 120.2
C6-C5-H5 120.2 C1-C6-C5 117.51(11)
C1-C6-C7 124.48(11) C5-C6-C7 118.01(11)
O2-C7-O3 113.99(11) O2-C7-C6 108.10(10)
O3-C7-C6 112.35(10) O2-C7-C8 108.60(10)
O3-C7-C8 104.46(10) C6-C7-C8 109.16(10)
F2-C8-F1 107.48(11) F2-C8-F3 107.35(11)
F1-C8-F3 107.07(11) F2-C8-C7 111.04(11)
F1-C8-C7 111.15(11) F3-C8-C7 112.49(11)
O1-N1-N1 122.12(13) O1-N1-C1 120.92(10)
N1-N1-C1 116.48(12) C7-O2-H2A 109.8(14)
C7-O3-H3A 106.6(13) O4-S1-C10 105.14(8)
195

O4-S1-C9 105.66(8) C10-S1-C9 98.21(8)
S1-C9-H9A 109.5 S1-C9-H9B 109.5
H9A-C9-H9B 109.5 S1-C9-H9C 109.5
H9A-C9-H9C 109.5 H9B-C9-H9C 109.5
S1-C10-H10A 109.5 S1-C10-H10B 109.5
H10A-C10-H10B 109.5 S1-C10-H10C 109.5
H10A-C10-H10C 109.5 H10B-C10-H10C 109.5
O5-S2-C11A 104.39(17) O5-S2-C12 106.9(2)
O5-S2-C12A 104.8(2) C11A-S2-C12A 100.7(2)
O5-S2-C11 108.70(18) C12-S2-C11 96.3(3)
S2-C11-H11A 109.5 S2-C11-H11B 109.5
H11A-C11-H11B 109.5 S2-C11-H11C 109.5
H11A-C11-H11C 109.5 H11B-C11-H11C 109.5
S2-C12-H12A 109.5 S2-C12-H12B 109.5
H12A-C12-H12B 109.5 S2-C12-H12C 109.5
H12A-C12-H12C 109.5 H12B-C12-H12C 109.5
S2-C11A-H11D 109.5 S2-C11A-H11E 109.5
H11D-C11A-H11E 109.5 S2-C11A-H11F 109.5
H11D-C11A-H11F 109.5 H11E-C11A-H11F 109.5
S2-C12A-H12D 109.5 S2-C12A-H12E 109.5
H12D-C12A-H12E 109.5 S2-C12A-H12F 109.5
H12D-C12A-H12F 109.5 H12E-C12A-H12F 109.5

Table 6: Torsion angles (°) for 8d
C6-C1-C2-C3 -1.49(19) N1-C1-C2-C3 -179.89(11)
C1-C2-C3-C4 -1.10(19) C2-C3-C4-C5 2.8(2)
196

C2-C3-C4-Br1 -174.98(10) C3-C4-C5-C6 -1.88(19)
Br1-C4-C5-C6 175.86(9) C2-C1-C6-C5 2.38(18)
N1-C1-C6-C5 -179.37(11) C2-C1-C6-C7 -177.81(12)
N1-C1-C6-C7 0.44(19) C4-C5-C6-C1 -0.69(18)
C4-C5-C6-C7 179.48(11) C1-C6-C7-O2 -18.33(16)
C5-C6-C7-O2 161.48(11) C1-C6-C7-O3 -144.98(12)
C5-C6-C7-O3 34.83(15) C1-C6-C7-C8 99.63(14)
C5-C6-C7-C8 -80.56(14) O2-C7-C8-F2 -55.81(14)
O3-C7-C8-F2 66.18(13) C6-C7-C8-F2 -173.46(10)
O2-C7-C8-F1 63.79(13) O3-C7-C8-F1 -174.22(10)
C6-C7-C8-F1 -53.86(13) O2-C7-C8-F3 -176.15(10)
O3-C7-C8-F3 -54.16(14) C6-C7-C8-F3 66.20(14)
C2-C1-N1-O1 85.13(14) C6-C1-N1-O1 -93.26(15)
C2-C1-N1-N1 -87.05(16) C6-C1-N1-N1 94.57(16)

Table 7: Anisotropic atomic displacement parameters (Å
2
) for 8d
The anisotropic atomic displacement factor exponent takes the form: -2π
2
[
h
2
a
*2
U11 + ... + 2 h k a
*
b
*
U12 ]
U 11 U 22 U 33 U 23 U 13 U 12
C1 0.0129(5) 0.0124(5) 0.0126(5) 0.0061(4) 0.0046(4) 0.0039(4)
C2 0.0153(6) 0.0150(6) 0.0114(5) 0.0050(4) 0.0017(4) 0.0034(4)
C3 0.0136(5) 0.0143(6) 0.0139(5) 0.0044(4) 0.0018(4) 0.0011(4)
C4 0.0149(5) 0.0143(6) 0.0154(5) 0.0080(4) 0.0056(4) 0.0031(4)
C5 0.0149(5) 0.0153(6) 0.0114(5) 0.0059(4) 0.0036(4) 0.0037(4)
C6 0.0123(5) 0.0120(5) 0.0113(5) 0.0040(4) 0.0026(4) 0.0037(4)
C7 0.0136(5) 0.0130(5) 0.0112(5) 0.0049(4) 0.0028(4) 0.0026(4)
197

U 11 U 22 U 33 U 23 U 13 U 12
C8 0.0183(6) 0.0151(6) 0.0163(6) 0.0045(5) 0.0037(5) 0.0025(5)
N1 0.0136(5) 0.0130(5) 0.0103(4) 0.0055(4) 0.0028(4) 0.0040(4)
O1 0.0220(5) 0.0157(4) 0.0205(4) 0.0108(4) 0.0074(4) 0.0096(4)
O2 0.0126(4) 0.0191(5) 0.0126(4) 0.0059(3) 0.0025(3) -0.0021(3)
O3 0.0184(4) 0.0169(4) 0.0118(4) 0.0058(3) 0.0001(3) 0.0053(4)
F1 0.0233(4) 0.0199(4) 0.0265(4) 0.0083(3) 0.0026(3) 0.0098(3)
F2 0.0249(4) 0.0144(4) 0.0225(4) -0.0001(3) 0.0000(3) 0.0004(3)
F3 0.0331(5) 0.0241(4) 0.0225(4) 0.0068(3) 0.0171(4) 0.0094(4)
Br1 0.01991(7) 0.01960(7) 0.01839(7) 0.01048(5) 0.00375(5) -0.00174(5)
S1 0.01942(16) 0.01574(15) 0.02706(17) 0.00578(13) 0.00468(13) 0.00593(12)
C9 0.0431(10) 0.0186(7) 0.0404(9) 0.0150(7) 0.0158(8) 0.0081(7)
C10 0.0286(8) 0.0280(8) 0.0272(7) 0.0122(6) 0.0083(6) 0.0153(6)
O4 0.0276(5) 0.0158(5) 0.0258(5) 0.0040(4) 0.0016(4) 0.0065(4)
S2 0.01390(15) 0.02120(17) 0.03176(18) 0.00883(14) 0.00468(13) 0.00210(12)
C11 0.028(2) 0.042(4) 0.030(3) 0.022(3) 0.0060(17) 0.009(2)
C12 0.039(3) 0.036(4) 0.029(2) 0.010(2) 0.008(2) 0.018(3)
C11A 0.0299(19) 0.053(4) 0.027(2) 0.021(2) 0.0030(15) 0.015(2)
C12A 0.043(3) 0.024(2) 0.036(2) 0.0045(17) 0.0070(19) 0.014(2)
O5 0.0150(5) 0.0214(5) 0.0385(6) 0.0097(5) 0.0038(4) 0.0031(4)

Table 8: Hydrogen atomic coordinates and
isotropic atomic displacement parameters
(Å
2
) for 8d
x/a y/b z/c U(eq)
H2 0.2172 0.2956 0.4249 0.017
198

x/a y/b z/c U(eq)
H3 0.0809 0.1383 0.5114 0.018
H5 0.3769 0.3975 0.8642 0.017
H2A 0.729(2) 0.718(2) 0.7904(19) 0.024
H3A 0.668(2) 0.496(2) 0.8700(19) 0.024
H9A 0.5911 -0.0838 0.6509 0.049
H9B 0.6062 0.0323 0.7995 0.049
H9C 0.7530 0.0201 0.7456 0.049
H10A 0.6891 0.0291 0.4855 0.04
H10B 0.8409 0.1344 0.5953 0.04
H10C 0.7508 0.2161 0.5225 0.04
H11A 0.0115 0.7304 1.0232 0.047
H11B 0.1222 0.6322 0.9606 0.047
H11C -0.0525 0.5710 0.8903 0.047
H12A -0.0363 0.5512 0.6714 0.052
H12B 0.1400 0.5806 0.7181 0.052
H12C 0.0791 0.6705 0.6368 0.052
H11D 0.0663 0.8452 1.0529 0.053
H11E 0.1351 0.6989 0.9935 0.053
H11F -0.0422 0.6705 0.9583 0.053
H12D -0.0707 0.5219 0.7173 0.055
H12E 0.1044 0.5389 0.7325 0.055
H12F 0.0177 0.5926 0.6330 0.055

Abstract (if available)

Abstract Organic photochemical reactions can be used to synthesize a wide array of compounds. Often these compounds obtained as a result of photochemical reactions are complex and cannot be synthesized easily by conventional chemical methods. In this work, we exploit the photochemistry of the o-nitrobenzylic framework. Nitrocompounds on irradiation result in the formation of nitroso, azo, azoxy arenes, diazepine oxides, isoxazoles, acridones which have value in the material and medicinal chemistry. We extend this well-known chemistry to o-nitrobenzylic systems containing trifluoromethyl moiety. Molecules containing the trifluoromethyl moiety are also highly valued in medicinal chemistry and are found in many commercially available drugs. In this work, we attempt to combine both of these frameworks together in the effort to generate new series of fluoroorganic molecules that could have potential medical and material value. ❧ In the first chapter I briefly introduce basic concepts in photochemistry and explain in detail the photochemistry of the o-nitrobenzylic /2-nitrobenzylic compounds, the mechanism involved, its synthetic utility as photosynthons and photolabile protecting groups. ❧ In the second chapter there is a brief introduction into the reasoning involved in choosing to work with the photosynthon 2-nitrophenyl-α-trifluoromethyl carbinols. We describe the solvent controlled synthesis using these alcohols as substrate to produce 2,2'-bis(trifluoroacetyl)azoxy-benzenes, 2-trifluorocetyl nitrosoarenes and trifluoromethylated benzisoxazoles in one step using UV-B light without any catalyst or reagent. Additionally, we also describe the NMR analysis which explains the formation of trifluoromethylated benzisoxazoline. We also perform a laser flash photolysis study of these compounds in isopropanol to gain insights into the intermediates being generated on the pico-second time scale. This chapter also contains all the supplementary data.

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Asset Metadata

Creator Belligund, Kavita (author)

Core Title 2-nitrophenyl-α-trifluoromethyl carbinols as smart synthons for novel fluoroorganics

School College of Letters, Arts and Sciences

Degree Doctor of Philosophy

Degree Program Chemistry

Publication Date 05/02/2019

Defense Date 03/18/2019

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag fluorine chemistry, azoxy,isoxazoline,nitro,nitroso,OAI-PMH Harvest,photochemistry,trifluoromethyl

Format application/pdf (imt)

Language English

Contributor Electronically uploaded by the author (provenance)

Advisor Prakash, G. K. Surya (committee chair), Haiges, Ralf (committee member), Shing, Katherine (committee member)

Creator Email belligun@usc.edu,kavitabelligund@gmail.com

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c89-166069

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