� ����

������������

�

SPECTRAL INVESTIGATIONS AND A

TD-DFT STUDY ON THE SINGLET AND

TRIPLET EXCITED-STATES UV-VIS

ANALYSES OF HETEROCYCLIC 5-

NITRO-1,3-BENZODIOXOLE

�

10.1. INTRODUCTION

1,3-Benzodioxoles occur widely in plant products, some of which are known

to show potent antioxidant and antibacterial activities [205]. It has recently been

reported that 1,3-benzodioxole derivatives possess cytotoxic activity against several

human tumour cell lines including human colon carcinoma cells [206] and multidrug-

resistant nasopharyngeal carcinoma cells [207]. On this basis and in pursuing the

interest in the study of new anticancer agents [208-210], the spectroscopic

investigations have been done on a 1,3-benzodioxole derivative such as 5-nitro-1,3-

benzodioxole (NBD).

Recently, Yonggang He et al., [211] have performed cation vibrational energy

levels of 1,3-benzodioxole obtained via zero kinetic energy photoelectron spectroscopy.

Synthesis and characterization of asymmetric o- and m-nitrobenzoic acids with a

1,3-benzodioxole skeleton has been performed by Masaya Suzuki et al., [205]. A

computational study on reminiscence of benzene in the spectroscopy of 1,3-benzodioxole

has been reported by Emanuela Emanuele et al., [212]. So far, the vibrational spectra

and the theoretical calculations of 5-nitro-1,3-benzodioxole (NBD) have not been

reported except in this work. Therefore, we have studied the spectral investigations of

� ����

NBD. The main objective of the present study is to investigate in detail vibrational

spectral analysis and electronic properties of NBD using ab initio/HF and

DFT/B3LYP computations.

10.2. EXPERIMENTAL SECTIONS

The pure 5-nitro-1,3-benzodioxole (NBD) was obtained from Lancaster

Company, USA that is of spectroscopic grade and hence used for recording the

spectra as such without any further purification. The FT-IR of NBD was measured in

the BRUKER IFS 66V spectrometer in the range 4000-400 cm-1

. The FT-Raman

spectrum of NBD was also recorded in BRUKER RFS 100/S instrument equipped

with Nd:YAG laser source operating at 1064 nm wavelength and 150 mW powers in

the range 3500-50 cm-1

.

10.3. QUANTUM CHEMICAL CALCULATIONS

The first task for the computational work was to determine the optimized

geometry of the compound using GAUSSIAN 09W [45] program package. It is well

known in the quantum chemical literature that the hybrid B3LYP [20,21] method

based on Becke’s three parameter functional of DFT yields a good description of

harmonic vibrational wavenumbers for small and medium sized molecules than HF

and flexible basis set 6-311++G level to perform accurate calculations on the title

compound were chosen. However, the frequency values computed at these levels

contain known systematic errors. In general theoretical calculations symmetrically

overestimate the vibrational wavenumbers. Hence, the vibrational frequencies

theoretically calculated are scaled down by using MOLVIB 7.0 version written by

Tom Sundius [55,44]. After scaling with a scaling factor, the deviation from the

� ����

experiment is more reliable. Analytic frequency calculations at the optimized

geometry were done to confirm the optimized structure to be an energy minimum and

to obtain the theoretical vibrational spectra. Using above mentioned methods the

following analyses such as electronic properties, NBO, HOMO-LUMO, NMR, UV-

VIS and thermal properties were carried out. The first hyper polarizability was

calculated to study the NLO properties.

10.4. RESULT AND DISCUSSION

10.4.1. Molecular geometry

The numbering of the atoms in 5-nitro-1,3-benzodioxole (NBD) is depicted in

Fig 10.1. The optimized geometries of NBD with HF and B3LYP methods are listed

in Table 10.1. Previously reported structural parameters determined by microwave

spectroscopy [213] are also included for comparison in Table 10.1. The bond lengths

calculated at the HF level are obviously underestimated, whereas DFT level makes

them closer to the microwave data. The overall structural parameters at B3LYP level

represent definite improvements on the HF results.

10.4.2. Vibrational spectral analysis

The title compound, NBD, has C1 point group symmetry, consists of 17 atoms,

so it has 45 normal vibrational modes. The calculated vibrational wavenumbers using

different methods were compared with the experimentally observed values.

Comparison of the frequencies calculated at HF and DFT with the experimental

values (Table 10.2) reveal the overestimation of the calculated vibrational modes due

to neglect of anharmonicity in real system. To certain extend inclusion of electron

correlation in the density functional theory; reduce the values of the frequencies a

�

�

Fig. 10.1: Molecular structure of 5-nitro-1,3-benzodioxole�

�

� ����

little. Although basis sets are sensitive, the computed harmonic vibrations are only

marginal as observed in the DFT values using 6-311++G. It is customary to scale

down the calculated harmonic frequencies in order to develop the agreement with the

experiment without affecting the level of calculations. The scaled calculated

frequencies minimize the root-mean square difference between calculated and

experimental frequencies for bands with definite identifications. The FT-IR and FT-

Raman spectra of CNA are shown in Figs 10.2 and 10.3 and they are interpreted as

follows.

10.4.2.1. C–H vibration

The aromatic structure shows the presence of C–H stretching vibration in the

region 3000–3100 cm-1

[62]. There are three stretching vibrations are identified for

C–H stretching at 3112, 3035 and 3000 cm-1

. The theoretically computed (scaled)

values for C–H vibrations using B3LYP/6-311++G method show a good agreement

with recorded spectrum. The bands due to the ring C–H in-plane bending are usually

observed in the region 1000–1300 cm-1

. In the title compound, these vibrations are

observed at 1225, 1065 and 1055 cm-1

. The C–H out-of plane bending vibrations are

usually observed between 750 and 1000 cm-1

[214]. In the present compound, these

vibrations are observed at 850, 808, and 730 cm-1

.

10.4.2.2. CH2 vibrations

The ethyl group of the title compound gives rise to four stretching modes and

the couple of scissoring, wagging, rocking and twisting modes. The band observed at

2966 cm-1

in FT-IR is assigned to asymmetric stretching mode of the ethyl group of

NBD. The band at 2920 cm-1

is designated as symmetric stretching modes. One of the

��

� ��

��

� � � � � �

Fig

. 10.

2: F

T-I

R s

pec

tru

m o

f 5-

nit

ro-1

,3-b

enzo

dio

xole

.

Fig

. 10.

3: F

T-R

aman

sp

ectr

um

of

5-n

itro

-1,3

-ben

zod

ioxo

le.

� ����

CH2 deformation modes called CH2 scissoring generates band at 1515 in FT-IR and

1505 in FT-Raman spectra, respectively. The band at 1410 cm-1

in FT-IR and 1430

cm-1

in FT-Raman are attributed to CH2 wagging vibrations. The peak at 1160 cm-1

in

FTIR is ascribed to ethyl twisting vibrations. The title compound display the peak at

1070 cm-1

in FT-IR spectrum has been ethyl rocking vibration. All these ethyl

vibrations are agreed well with the literature [215].

10.4.2.3. Nitro group vibrations

Aromatic nitro compounds have strong absorptions due to asymmetric and

symmetric stretching vibrations of the NO2 group at 1570–1485 and 1370–1320 cm-1,

respectively. Hydrogen bonding has a little effect on NO2 asymmetric stretching

vibrations [65]. In NBD, two FTIR bands at 1540 and 1350 cm-1

have been assigned

to asymmetric and symmetric stretching modes of NO2. Aromatic nitro compounds

have a band of weak to medium intensity in the region 590–500 cm-1

[62] due to the

out of plane bending deformations mode of NO2 group. This is observed in NBD at

505 cm-1

. The in-plane NO2 deformations vibrations have a week to medium

absorption in the region 775–660 cm-1

[216]. In NBD, NO2 deformations are found at

780 and 710 cm-1

and NO2 twisting vibration is observed at 30 cm-1

. These vibrations

are not affected much by other modes. This is a unique occurrence of NO2.

10.4.2.4. C-N vibrations

NO2 group attached to ring carbon atom C5 of NBD gives rise to three

vibrational modes such as C-N stretching, C-N in-plane and out-of-plane bending. In

the present study, the band at 1110 cm-1

in FT-IR is assigned to νC-N mode which is

well agreed with the literature [217]. The assignments of in-plane and out-of-plane

C-N bending modes are made at 610 and 380cm-1

, respectively.

� ����

10.4.2.5. Skeletal vibrations

The bands observed in the infrared spectrum of NBD at 1615, 1590, 1468,

1375, 1278 and 1250 cm-1

are ascribed to the benzene ring stretching modes and the

corresponding FT-Raman bands are appeared at 1620, 1610, 1460, 1378, 1288 cm-1

.

The ring2 stretching vibrations are observed at 1035, 910, 895, 678 cm-1

in FT-IR

spectrum and at 1030, 900 cm-1

in the FT-Raman spectrum. Also, the benzene ring

and ring2 in-plane vibrations are assigned to the observed frequencies at 580, 542 cm-1

and 525, 493, 402 cm-1

in FT-IR and FT-Raman spectra, respectively. The out-of-

plane bending vibrations are established at 345, 312, 210 155, 75 cm-1

in FT-Raman

spectrum. All these vibrations are agreed well with the literature [215].

10.5. HOMO-LUMO ANALYSIS

The orbital energy level analysis for NBD at the BLYP level shows EHOMO

(highest occupied molecular orbital) and ELUMO (lowest unoccupied molecular orbital)

values of -7.524 eV and -4.62 eV, respectively. The magnitude of the HOMO–LUMO

energy separation could indicate the reactivity pattern of the molecule. The charge

densities of the HOMO and LUMO are shown in Fig.10.4. The HOMO is located on

the C5–C6, C7–C8 and C9–C4 bonds of the benzene ring (C1–C6) as well as on the

oxygen atoms of nitro group with only minor population, O2 and O3 and CH2 group

of dioxole ring. The LUMO in NBD, however, populates on the carbon atoms (C4, C5

and C6) and the NH2 group of the benzene ring and O1 atom. The population of

LUMO on the bonding between C1–C2, C6–C8 and N1–C9 forms antibonding

orbitals. Minor population can be located on the oxygen atoms of the methoxy groups.

These population shows that the charge transfer is taking place from NO2 group to

rings. According to molecular orbital theory, HOMO and LUMO are two important

factors influencing the bioactivity.

�

�

�

�

(a) HOMO Energy=-7.524 eV

�

�

�

�

�

�

�

�

�

(b) LUMO Energy= - 4.62 eV

�

Fig. 10.4: Charge densities of (a) HOMO and (b) LUMO of 5-nitro-1,3-benzodioxole.

�

�

� ����

10.6. NBO ANALYSIS

NBO analysis has been performed on the compound at the B3LYP/6-311++G

level in order to elucidate the intramolecular, rehybridization and delocalization of

electron density within the compound.

The larger the E(2)

(energy of hyperconjugative interactions) value, the more

intensive is the interaction between electron donors and electron acceptors, i.e. the

more donating tendency from electron donors to electron acceptors the greater the

extent of conjugation of the whole system. Delocalization of electron density between

occupied Lewis-type (bond or lone pair) NBO orbitals and formally unoccupied (anti-

bond or Rydgberg) non-Lewis NBO orbitals correspond to a stabilizing donor–

acceptor interaction.

The intramolecular interactions are formed by the orbital overlap between

�(C- C), �*(C-C), �(C-C), �*(C-C) bond orbital which results intramolecular charge

transfer (ICT) causing stabilization of the system. These interactions are observed as

increase in electron density (ED) in C-C anti-bonding orbital that weakens the

respective bonds. These intramolecular charge transfer (���*, ���*) can induce

large nonlinearity of the compound.

The strong intramolecular hyper conjugation interaction of the � and �

electrons of C-C, C-H, C-N and C-Cl to the anti C-C, C-H and C-N bond leads to

stabilization of some part of the ring as evident from Table 10.3. The intramolecular

interactions are formed by the orbital overlap between bonding (C-C) and (C-C)

antibond orbital which results intramolecular charge transfer (ICT) causing

stabilization of the system. These interactions are observed as increase in electron

density (ED) in C-C anti-bonding orbital that weakens the respective bonds. The

� ����

strong intramolecular hyper conjugative interaction of the � electron of (C4- C9)

distribute to �*(C5-C6) and �*(C7-C8) of the ring which leads to strong

delocalization of 74.6844 and 89.7468 kJ/mol, respectively. The �(C5-C6) bond is

interacting with �*(C4–C9) and �*(C8-C9) with the energies 84.6423, and 69.0778

KJ/mol for NBD. The same �(C5-C6) bond interacts with �*(N15-O17) with the

highest energy 143.679 KJ/mol resulting the strong stabilization of NBD. The

electrons of LP(3) O16 can be redistributed into �*(N15–O17) with the potential of

744.3754 kJ/mol with external perturbations, then, the redistributed electrons of the

�* (N15–O17) can be easily transported to its neighbouring anti-bond of �*(C5 –C6)

with the higher interaction energies of 66.7348 kJ/mol. Thus, the electrons of NO2

group are transported into ring of the compound.

10.7. UV-VIS ANALYSIS

10.7.1. Singlet excited states and absorption spectra

Calculated absorption spectrum with their oscillator strengths, assignment,

configurations, excitation energies, excitations with maximum coefficients and the

experimental values are summarized in Table 10.4. The corresponding simulated UV–

VIS absorption spectrum of NBD, presented as oscillator strength against wavelength,

are presented in Fig.10.5. In order to explain the electronic transition characteristics,

the relative frontier molecular orbital compositions of NBD in acetonitrile are

provided in Table 10.4. Fig. 10.5 shows that the lowest lying distinguishable

singlet�singlet first absorption band, originating from excited state 5, was at 239.40

nm. This absorption band was assigned as a HOMO – LUMO+1 transition with the

excitation energy of 5.1789 eV. The lowest lying absorption peak of 2, at 315.39 nm,

� ����

is best described as a HOMO-1->LUMO transition with the oscillator strength of

0.1490. For band 3, it appeared that the HOMO-LUMO transition originating from

excited state 1, located at 401.69 nm.

10.7.2. Triplet excited states and emission properties

The triplet excited states of NBD were computed, using acetonitrile as a

medium, based on their lowest lying triplet state geometry. The corresponding triplet

excited state emission spectrum of NBD is presented in Fig. 10.6. The energies of the

triplet excited states are provided relative to the singlet ground state in the lowest

lying triplet state-optimized geometry. In NBD, only one emission band at 475.80 nm

has been observed with the excitation energy of 2.6058 eV.

10.8. NMR SPECTRAL ANALYSIS

Full geometry optimization of NBD was performed at the gradient corrected

DFT using the hybrid B3LYP method based on Becke’s three parameters functional

of DFT. Then, gauge-including atomic orbital (GIAO)1H,

13C

15N and

17O NMR

chemical shift calculations of the compound have been made by same method. The

computed and experimental 1H,

13C

15N and

17O NMR chemical shifts are tabulated in

Table 10.5. Atom positions were numbered according to the Fig. 10.1. Aromatic

carbons give signals in overlapped areas of the spectrum with chemical shift values

from 100 to 150 ppm [79,80]. In our present investigation, the chemical shift values

of aromatic carbons are in the range 104.3849–119.8578 ppm. The nitro group which

is an electronegative functional group polarizes the electron distribution; therefore the

calculated 13

C NMR chemical shift value of C5 bonded to nitro group is high

compared to other carbons, observed at 146.8189 ppm. Similarly, C8 and C9 atoms

�

�

�

�

�

�

�

�

�

�

�

�

Fig. 10.5: Singlet excited state absorption spectrum of 5-nitro-1,3-benzodioxole. �

�

�

��

�

�

�

� �

�

�

�

�

�

�

�

�

�

�

Fig. 10.6: Triplet excited state emission spectrum of 5-nitro-1,3-benzodioxole

� ����

have larger 13

C NMR chemical shifts (152.6968 and 147.1116 ppm, respectively) than

the other ring carbon atoms. The signals for aromatic protons in the rings were

observed at 5.8818 - 7.1165 ppm. The chemical shift of 15

N ranges from 0 to 900 ppm

[155]. Since in our investigation, the peak at 428.5877 ppm is assigned to N15 of

nitro group.17

O has a very wide chemical shift range which for small molecules

partially compensates for its broad signals. The chemical shift of 17

O ranges from -40

to 1120 ppm [156]. In the title compound, the peaks at 793.4796 and 792.1667 ppm

are assigned to nitro group oxygens, O17 and O16, respectively. Correspondingly the

dioxole ring oxygen’s chemical shifts (O1 and O3) are obtained at 158.0709 and

143.8771 ppm. Obviously, the oxygen chemical shifts of nitro group are larger than

other oxygen due to the environment.

10.9. FIRST HYPERPOLARIZABILITY

The electronic and vibrational contributions to the first hyperpolarizability

have been studied theoretically for many organic and inorganic systems. The values

of the first hyperpolarizability were found to be quite large for the so-called push–pull

molecules, i.e. p-conjugated molecules with the electron donating and the electron

withdrawing substituents attached to a ring, compared to the monosubstituted systems

[24]. This type of functionalization of organic materials, with the purpose of

maximizing NLO properties, is still commonly followed route.

The first hyperpolarizability of title compound is calculated using B3LYP/6-

311++G method, based on the finite-field approach. In the presence of an applied

electric field, the energy of a system is a function of the electric field. First order

hyperpolarizability (�) is a third rank tensor that can be described by 3×3 ×3 matrices.

� ����

The components of are defined as the coefficients in the Taylor series expansion of

the energy in the external electric field. When the external electric field is weak and

homogeneous, this expansion becomes:

0

� � �� � � ��� � � �

1 1E = E -� F - � F F - � F F F +...

2 6

where E0 is the energy of the unperturbed molecule, F� is the field at the origin, and

��, ��� and ���� are the components of dipole moment, polarizability and the first order

hyperpolarizability, respectively. The total static dipole moment (�) and the mean first

hyperpolarizability (�) using the x, y, z components, they are defined as:

( )1

2 2 2 2

x y z� = � +� +�

( )1

2 2 2 2

x y z�= � +� +�

where

x xxx xyy xzz� =� +� +�

y yyy xxy yzz� =� +� +�

z zzz xxz yyz� =� +� +�

Since the value of hyperpolarizability (�) of the GAUSSIAN 09W output is

reported in atomic units (a.u.), the calculated values should have been converted into

electrostatic units (e.s.u) (1 a.u. = 8.639 × 10−33

e.s.u). The total molecular dipole

moment and first hyperpolarizability are 5.7519 Debye and 13.497 × 10−30

e.s.u,

respectively and are depicted in Table 10.6. Total dipole moment of title compound is

approximately four times greater than those of urea and first hyperpolarizability of

title compound is 36 times greater than those of urea (� and � of urea are 1.3732

Debye and 0.3728 × 10−30

esu obtained by HF/6-311G(d,p) method).

� ����

10.10. THERMODYNAMIC PROPERTIES

On the basis of vibrational analysis, the statically thermodynamic functions

such as heat capacity (C0

p,m), entropy (S0

m ), and enthalpy changes (H0

m ) for NBD

were obtained from the theoretical harmonic frequencies and listed in Table 10.7.

From this table, it can be observed that these thermodynamic functions are increasing

with temperature ranging from 100 to 1000 K due to the fact that the molecular

vibrational intensities increase with temperature as shown Fig 10.7.

10.11. CONCLUSION

The vibrational wavenumbers of 5-nitro-1,3-benzodioxole were calculated and

the complete assignments were performed on the basis of the total energy distribution

(TED) of the vibrational modes. Results are compared with experimental observed

FT-IR and FT-Raman spectra. After scaling down, the calculated wavenumbers show

good agreement with experimental spectra. The NBO analysis of 5-nitro-1,3-

benzodioxole showed effective energy interaction between the nitrogen lone pair

LP(3) O16 and the sigma antibonding orbitals of the N15–O17 bond. The ground state

geometry and excited state geometry have been theoretically investigated on

absorption and emission properties of 5-nitro-1,3-benzodioxole. The positions of

hydrogen and carbon atoms of title compounds are determined with help of computed

1H and

13C NMR chemical shifts. The electronic properties were also discussed

theoretically. Non-linear optical behaviour of the examined molecule was investigated

by the determination of the hyperpolarizability. These results indicate that the 5-nitro-

1,3-benzodioxole is a good candidate of nonlinear optical materials.

�

�

�

�

�

�

�

�

�

�

�

�

�

� �

� �

� � �

Fig. 10.7: Thermodynamic parameters of 5-nitro-1,3-benzodioxole at various temperature

�

�����

Tab

le 1

0.1:

O

pti

miz

ed p

aram

eter

s of

5-n

itro

-1,3

-ben

zod

ioxo

le b

y H

F a

nd

B3L

YP

met

hod

s u

sin

g 6-

311+

+G

bas

is s

et.

Val

ues

V

alu

es

Val

ues

HF

B

3LY

P

HF

B

3LY

P

HF

B

3LY

P

Bon

d

len

gth

(Å

) 6-

311+

+G�

6-31

1++

G�

Exp

. va

luea

Bon

d a

ngl

es (

o )

6-31

1++

G

6-31

1++

G

Exp

. va

luea

Dih

edra

l an

gles

(o )

6-31

1++

G

6-31

1++

G

O1

-C2

1

.47

92

1

.47

13

-

C2

-C1

-C8

106

.599

4

106

.605

8

- C

8-O

1-C

2-C

3

0.0

174

0

.00

61

O1

-C8

1

.39

38

1

.38

76

1

.36

8

O1

-C2

-O3

106

.414

5

106

.560

3

- C

8-O

1-C

2-H

13

-1

17

.98

46

-1

18

.068

2

C2

-O3

1

.47

2

1.4

648

1

.43

2

O1

-C2

-H1

3

109

.034

7

109

.047

- C

8-O

1-C

2-H

14

1

18

.020

4

118

.080

4

C2

-H1

3

1.0

855

1

.08

65

1

.09

4

O1

-C2

-H1

4

109

.035

6

109

.047

1

- C

2-O

1-C

8-C

7

179

.991

-1

80

.002

9

C2

-H1

4

1.0

855

1

.08

65

1

.09

4

O3

-C2

-H1

3

109

.486

2

109

.474

2

- C

2-O

1-C

8-C

9

-0.0

10

7

-0.0

03

8

O3

-C9

1

.40

25

1

.39

59

-

O3

-C2

-H1

4

109

.486

6

109

.474

1

- C

1-C

2-O

3-C

9

-0.0

17

7

-0.0

06

1

C4

-C5

1

.40

83

1

.40

53

1

.40

0

H1

3-C

2-H

14

1

13

.158

2

113

.030

1

- H

13

-C2

-O3

-C9

1

17

.685

8

117

.786

7

C4

-C9

1

.37

36

1

.37

14

1

.38

7

C2

-O3

-C9

106

.519

7

106

.514

5

- H

14

-C2

-O3

-C9

-1

17

.722

5

-11

7.7

99

C4

-H1

0

1.0

767

1

.07

78

1

.07

8

C5

-C4

-C9

115

.616

7

115

.569

- C

2-O

3-C

9-C

4

-179

.990

3

180

.003

C5

-C6

1

.39

61

1

.39

33

1

.40

0

C5

-C4

-H1

0

121

.186

5

121

.152

2

- C

2-O

3-C

9-C

8

0.0

117

0

.00

4

C5

-N1

5

1.4

592

1

.45

32

-

C9

-C4

-H1

0

123

.196

7

123

.278

8

- C

9-C

4-C

5-C

6

0.0

003

0

.00

01

C6

-C7

1

.40

21

1

.39

96

-

C4

-C5

-C6

123

.001

3

123

.058

4

- C

9-C

4-C

5-N

15

-1

79

.999

5

180

.000

2

C6

-H1

1

1.0

777

1

.07

89

-

C4

-C5

-N1

5

118

.141

7

118

.105

2

- H

10

-C4

-C5

-C6

-1

79

.999

5

180

.000

2

C7

-C8

1

.38

23

1

.38

-

C6

-C5

-N1

5

118

.857

1

18

.836

3

- H

10

-C4

-C5

-N1

5

0.0

008

0

.00

03

C7

-H1

2

1.0

785

1

.07

92

-

O1

6-N

15-O

17

1

23

.482

4

123

.600

7

- C

5-C

4-C

9-O

3

-179

.997

8

180

.001

C8

-C9

1

.39

62

1

.39

42

-

C5

-C6

-C7

119

.969

1

119

.997

7

12

0.5

C

5-C

4-C

9-C

8

-0.0

00

1

-0.0

00

1

N1

5-O

16

1

.26

85

1

.26

18

-

C5

-C6

-H1

1

119

.007

8

118

.951

5

- H

10

-C4

-C9

-O3

0

.00

2

0.0

009

N1

5-O

17

1

.26

87

1

.26

2

- C

7-C

6-H

11

121

.023

1

121

.050

8

- H

10

-C4

-C9

-C8

1

79

.999

7

-180

.000

2

C6

-C7

-C8

117

.062

3

117

.003

7

11

8.8

C

4-C

5-N

15

-O1

7

0.0

002

0

.0

C6

-C7

-H1

2

121

.684

1

121

.698

- C

6-C

5-N

15

-O1

6

0.0

005

0

.00

02

C8

-C7

-H1

2

121

.253

6

121

.298

4

- C

6-C

5-N

15

-O1

7

-179

.999

5

180

.000

2

O1

-C8

-C7

127

.553

2

127

.616

4

- C

5-C

6-C

7-C

8

-0.0

00

3

-0.0

00

1

O1

-C8

-C9

110

.325

6

110

.239

8

- C

5-H

6-C

7-H

12

1

79

.999

8

-180

.000

2

C7

-C8

-C9

122

.121

2

122

.143

8

12

0.7

H

11

-C6

-C7

-C8

1

79

.999

5

-180

.000

1

O3

-C9

-C4

127

.629

7

127

.692

9

- H

11

-H6

-H7

-H1

2

-0.0

00

4

-0.0

00

2

O3

-C9

-C8

110

.140

8

110

.079

7

- C

6-C

7-C

8-O

1

179

.998

6

-180

.000

8

C4

-C9

-C8

122

.229

4

122

.227

4

- C

6-C

7-C

8-C

9

0.0

005

0

.00

01

C5

-N1

5-O

16

1

18

.424

2

118

.372

1

- H

12

-C7

-C8

-O1

-0

.00

15

-0

.00

07

C5

-N1

5-O

17

1

18

.093

4

118

.027

2

- H

12

-H7

-C8

-C9

-1

79

.999

6

180

.000

2

�����

O1

-C8

-C9

-O3

-0

.00

07

-0

.00

01

O1

-C8

-C9

-C4

-1

79

.998

7

180

.000

8

C7

-C8

-C9

-O3

1

79

.997

8

-180

.000

9

C7

-C8

-C9

-C4

-0

.00

03

0

.0

C4

-C5

-C6

-C7

-0

.00

01

0

.0

C4

-C5

-C6

-C11

1

80

.000

1

18

0.0

N1

5-C

5-C

6-C

7

179

.999

7

179

.999

9

N1

5-C

5-C

6-C

11

-0.0

00

1

-0.0

00

1

C4

-C5

-N1

5-O

16

180

.000

3

18

0.0

a R

efer

the

refe

rence

[ 2

13]

�����

Tab

le 1

0.2:

V

ibra

tion

al a

ssig

nm

ents

of

exp

erim

enta

l fr

equ

enci

es o

f 5-

nit

ro-1

,3-b

enzo

dio

xole

alo

ng

wit

h c

alcu

late

d f

req

uen

cies

b

y H

F a

nd

B3L

YP

met

hod

s u

sin

g 6-

311+

+G

bas

is s

et.

Cal

cula

ted

fre

qu

ency

(cm

-1)

Exp

erim

enta

l fr

equ

ency

(c

m-1

) H

F/6

-311

++

G

B3L

YP

/6-3

11+

+G

S

.N

o F

T-I

R

FT

-Ram

an

Un

scal

ed

Sca

led

U

nsc

aled

S

cale

d

Ass

ign

men

ts w

ith

TE

D

(%)

1

31

12

-

32

73

31

29

3

25

2

31

18

ν

CH

(98

)

2

30

35

-

32

62

30

55

3

24

2

30

42

ν

CH

(89

)

3

30

00

-

32

43

30

11

3

22

2

30

08

ν

CH

(97

)

4

29

66

-

31

80

29

72

3

15

6

29

71

C

H2as

(88

)

5

29

20

-

30

99

29

45

3

08

0

29

31

C

H2ss

(90

)

6

16

15

1

62

0

16

63

16

35

1

65

6

16

22

B

enze

ne

rin

g

stre

tch

ing

(89

)

7

15

90

1

61

0

16

46

16

11

1

64

0

15

99

B

enze

ne

rin

g

stre

tch

ing

(91

)

8

15

40

-

15

58

15

65

1

56

2

15

49

N

O2 a

s

9

15

15

1

50

5

15

31

15

22

1

52

0

15

11

C

H2 s

cis

10

1

46

8

14

60

1

49

0

14

77

1

48

9

14

70

B

enze

ne

rin

g

stre

tch

ing

(90

)

11

1

41

0

14

30

1

45

5

14

22

1

45

0

14

19

C

H2

wag

12

1

37

5

13

78

1

41

5

13

79

1

41

7

13

78

B

enze

ne

rin

g

stre

tch

ing

(88

)

13

1

35

0

13

45

1

40

6

13

67

1

39

9

13

57

N

O2ss

14

1

27

8

12

88

1

29

9

12

89

1

30

3

12

81

B

enze

ne

rin

g

stre

tch

ing

(90

)

15

1

25

0

- 1

28

0

12

66

1

27

6

12

56

B

enze

ne

rin

g

stre

tch

ing

(92

)

�����

16

1

22

5

- 1

25

9

12

39

1

25

8

12

27

b

CH

(7

9)

17

1

16

0

- 1

17

2

11

67

1

17

5

11

62

C

H2 t

wis

t(7

4)

18

1

11

0

- 1

16

0

11

22

1

16

4

11

12

ν

CN

(89

)

19

1

07

0

- 1

14

0

10

65

1

14

3

10

68

C

H2 r

ock

(69

)

20

10

65

1

11

1

10

61

1

11

5

10

61

b

CH

(77

)

21

1

05

5

1

07

3

10

71

1

07

5

10

71

b

CH

(79

)

22

1

03

5

10

30

1

01

0

10

33

1

02

0

10

38

R

ing 2

str

etch

(90

)

23

9

10

9

00

9

86

92

1

99

3

91

1

Rin

g 2

str

etch

(89

)

24

8

95

-

92

0

90

8

92

7

90

3

Rin

g 2

str

etch

(91

)

25

8

50

-

91

9

86

6

91

9

85

6

�C

H(6

7)

26

8

08

-

87

8

81

9

87

3

81

9

�C

H(6

8)

27

7

80

-

85

3

79

2

85

8

78

6

NO

2sc

is(6

5)

28

7

30

8

05

8

09

74

9

80

9

73

9

�C

H(6

6)

29

7

10

7

15

7

94

72

8

79

1

71

7

NO

2 r

ock

(68

)

30

6

78

-

71

9

69

1

71

8

68

2

Rin

g 2

stre

tch

(88

)

31

6

10

-

71

9

62

2

70

7

61

1

bC

-N(6

9)

32

5

80

-

70

3

59

9

69

9

55

9

Ben

zen

e ri

ng b

end

(68

)

33

5

42

5

38

6

85

55

5

68

5

54

3

Ben

zen

e ri

ng b

end

(69

)

34

-

52

5

58

9

53

0

59

1

52

8

Ben

zen

e ri

ng b

end

(71

)

35

-

50

5

57

1

51

1

56

6

50

9

NO

2 w

ag(6

4)

36

-

49

3

54

8

50

4

54

6

49

2

Rin

g2

ben

d(6

5)

37

-

40

2

44

2

41

1

43

8

40

9

Rin

g2

ben

d(6

6)

�����

38

-

38

0

40

1

39

9

39

7

38

8

�C

N(6

7)

39

-

34

5

35

2

35

5

35

3

34

9

Ben

zen

e ri

ng o

ut

of

pla

ne

ben

din

g(6

2)

40

-

31

2

33

5

32

1

32

6

31

9

Ben

zen

e ri

ng o

ut

of

pla

ne

ben

din

g(6

6)

41

-

21

0

23

8

21

8

23

2

21

5

Rin

g2

ben

d t

ors

ion

(55

)

42

-

15

5

21

0

16

6

20

4

15

9

Ben

zen

e ri

ng o

ut

of

pla

ne

ben

din

g(5

8)

43

-

14

0

14

8

14

5

12

7

14

3

Bu

tter

fly(5

5)

44

-

75

9

3

82

7

0

80

R

ing2

ben

d t

ors

ion

(54

)

45

-

30

9

0

45

6

0

40

N

O2 t

wis

t(5

8)

Ab

bre

viat

ion

s:

ν –

str

etch

ing;

b –

ben

din

g;

sym

d –

sym

met

ric

defo

rmat

ion;

asym

d –

as

ym

metr

ic d

eform

ati

on;

trig

d-

trig

onal

def

orm

atio

n; �-o

ut

of

pla

ne

ben

din

g;

t –

tors

ion;

twis

t –

tw

isti

ng

; ss

– s

ym

met

ric

stre

tchin

g;

ass

- as

ym

met

ric

stre

tchin

g;

ipr

– i

n p

lane

rock

ing;

opr

– o

ut

of

pla

ne

rock

ing;

scis

– s

ciss

ori

ng;

rock –

rock

ing;

wag

– w

aggin

g.

� ����

Table 10.3: Selected second order perturbation energies E(2) associated with i->j delocalization in gas phase using B3LYP/6-311++G method and basis set.

Donor (i)

Type Acceptor

(j) Type

E(2)

(kJ mol-1) �j – �i

a

(a.u.) F(i,j)b

(a.u)

C5 - C6 �* 74.6844 0.29 0.066 C4 -C9 �

C7 - C8 �* 89.7468 0.29 0.072

C4 - C9 �* 84.6423 0.28 0.068

C8 - C9 �* 69.0778 0.28 0.061 C5 - C6 �

N15 - O17 �* 143.679 0.13 0.065

C4 - C9 �* 80.9186 0.29 0.067 C7 - C8 �

C5 - C6 �* 91.253 0.29 0.072

LP(2) O1 n2 C7 - C8 �* 120.374 0.33 0.093

LP(2) O3 n2 C4 - C9 �* 111.796 0.34 0.089

LP(2) O17 n2 C5 – N15 �* 44.3922 0.58 0.070

LP(2) O17 n2 N15 - O16 �* 79.0776 0.63 0.098

LP(2) O16 n2 C5 - N15 �* 44.9362 0.58 0.071

LP(2) O16 n2 N15 - O17 �* 79.3705 0.63 0.099

LP(3) O16 n3 N15 - O17 �* 744.3754 0.11 0.130

N15-O17 �* C5 - C6 �* 66.7348 0.16 0.061

� ����

Table 10.4: Singlet computed excitation energies, oscillator strength, electronic transition configuration wavelength of 5-nitro-1,3-benzodioxole using TD-DFT/B3LYP/6-311++G method and basis set inacetonitrile .

Excited States

EE (eV)

Oscillator strength

f Configuration

CI expansion coefficient

Wave length (nm)

1 3.0866 0.1415 42 → 44 0.14448

43 → 44 0.69077 401.69

2 3.4395 0.0000 41 → 44 0.70247 360.47

3 3.9312 0.1490 42 →44 0.68133

43 →44 -0.14350

43 → 45 -0.10942

315.39

4 3.9801 0.0001 39 → 44 0.70238 311.51

5 5.1789 0.1461 38 → 44 -0.12336

42 → 46 -0.20418

43 →45 0.64533

239.40

6 5.6293 0.0390 38 → 44 0.66297

40 →44 -0.12883

43 → 46 -0.16108

220.25

����

Tab

le 1

0.5:

C

alcu

late

d 13

C, 1

H, 1

5 N a

nd

17O

N

MR

iso

trop

ic c

hem

ical

sh

ifts

(al

l va

lues

in

pp

m)

of 4

-nit

ro-1

,3-b

enzo

dio

xole

usi

ng

DF

T/B

3LY

P/6

-311

++

G m

eth

od a

nd

bas

is s

et

Ato

ms

Ch

emic

al

shie

ldin

g

Ch

emic

al

shif

t A

tom

s C

hem

ical

shie

ldin

g

Ch

emic

al

shif

t A

tom

s C

hem

ical

shie

ldin

g

Ch

emic

al

shif

t

C8

2

9.7

68

8

15

2.6

96

8

H1

1

24

.76

56

7

.11

65

N

15

-1

70

.18

77

42

8.5

87

7

C9

3

5.3

54

14

7.1

11

6

H1

0

25

.01

41

6

.86

8

O1

7

-47

3.4

79

6

79

3.4

79

6

C5

3

5.6

46

7

14

6.8

18

9

H1

2

26

.00

03

5

.88

18

O

16

-4

72

.16

67

79

2.1

66

7

C6

6

2.6

07

8

11

9.8

57

8

H1

4

26

.36

88

5

.51

33

O

1

16

1.9

29

1

15

8.0

70

9

C2

7

5.6

10

7

10

6.8

54

9

H1

3

26

.36

91

5

.51

3

O3

1

76

.12

29

14

3.8

77

1

C7

7

5.8

14

3

10

6.6

51

3

C4

7

8.0

80

7

10

4.3

84

9

� ���

Table 10.6: Theoretical first hyperpolarizability of 5-nitro-1,3-benzodioxole using DFT/B3LYP/6-311++G method and basis set.

Parameters Values(a.u)

�xxx 1582.9896125

�xxy -297.6044822

�xyy 26.5978724

�yyy 111.5558416

�xxz -0.3246258

�yyz 0.0042833

�xzz -58.7957849

�yzz -4.2255076

�zzz -0.0090297

� 13.497×10−30

e.s.u

� ����

Table 10.7: Calculated specific heat capacity (C0p,m), entropy (S0

m), and

enthalpy (�H0m) at various temperature of 5-nitro-1,3-

benzodioxole using B3LYP/6-311++G method and basis set.

T (K) C0

p,m S0

m H0

m

100.00 290.71 67.97 4.95

200.00 349.63 108.02 13.68

298.15 401.06 152.73 26.46

300.00 402.00 153.57 26.75

400.00 452.18 196.29 44.29

500.00 499.94 231.79 65.76

600.00 544.79 259.95 90.40

700.00 586.59 282.16 117.55

800.00 625.47 299.88 146.68

900.00 661.65 314.26 177.42

1000.00 695.39 326.08 209.45