minor research project [12 mrp-1872/14-15/klmg016/ugc...

Theoretical Investigation of Non Linear Optical Properties of Molecules Containing Naphthalene Linked to Nitrophenyl Group

MINOR RESEARCH PROJECT [12th PLAN]

MRP-1872/14-15/KLMG016/UGC-SWRO

SUBMITTED TO

UNIVERSITY GRANTS COMMISSSION

PRINCIPAL INVESTIGATOR

ANJU LINDA VARGHESE

Assistant Professor Department of Chemistry

Catholicate College Pathanamthitta, Kerala

1

DECLARATION

I hereby declare that the minor research project “Theoretical Investigation of Non Linear

Optical Properties of Molecules Containing Naphthalene Linked to Nitrophenyl Group”is

an original record of studies and research carried out by me during the tenure of the project.

Date: 17 -02- 2017 Principal Investigator

Place: Pathanamthitta

ANJU LINDA VARHGESE

2

Date: 17 February 2017

CERTIFICATE

This is to certify that the Minor Research Project entitled “Theoretical Investigation of Non

Linear Optical Properties of Molecules Containing Naphthalene Linked to Nitrophenyl

Group”MRP-1872/14-15/KLMG016/UGC-SWRO submitted to University Grants Commission

is a bonafidework by ANJU LINDA VARHGESE of our institution.

Principal/Registrar Principal Investigator

3

Contents Page number

Chapter 1: Introduction 1

1.1 Linear Optical Properties 2

1.2 Non Linear Optical Properties 3

1.3 Density Functional Calculations 4

1.4 Basis sets 5

1.5 Objectives 9

Chapter 2: Experimental Section 10

2.1 Computational Details 11

2.2 Chemicals 11

2.3 Synthesis of N-(2,4-dinitrophenyl)naphthalene-1-amine 11

2.4 Characterization Techniques 12

Chapter 3: Results and Discussions 13

3.1 DFT studies on the electronic transitions of N-[3-(Naphthalene-1-yloxy)butyl]-2,4-dinitroaniline, N-[3-(Naphthalene-1-yloxy)butyl]-4-nitroaniline, and their azanaphthalene derivatives

14

3.2 DFT studies on the Non Linear Optical Properties of the above molecule and their structural relationships.

21

4

3.3 DFT studies on the electronic transitions of N-[3-(Quinoline-1-yloxy)butyl]-2,4-dinitroaniline , N-[3-(Quinoline-1-yloxy)butyl]-4-nitroaniline, and their position isomers

28

3.4 DFT studies on the electronic transitions of N-[3-(Quinoline-1-yloxy)butyl]-2,4-dinitroaniline , N-[3-(Quinoline-1-yloxy)butyl]-4-nitroaniline, and their position isomers

34

3.5 DFT studies on the electronic transitions of N-[(Naphthalen-5-yl)methyl]-4 nitrobenzamine and N-[(Naphthalen-5-yl)methyl]-2,4 dinitrobenzamine

36

3.6 DFT studies on the nonlinear optical properties of N-[(Naphthalen-5-yl)methyl]-4 nitrobenzamine and N-[(Naphthalen-5-yl)methyl]-2,4 dinitrobenzamine

38

3.7 DFT studies on the electronic transitions of N-(4-Nitrophenyl)naphthalene-1-amine and N-(2,4-dinitrophenyl)naphthalene-1-amine

39

3.8 DFT studies on the Nonlinear optical properties of N-(4-Nitrophenyl)naphthalene-1-amine and N-(2,4-dinitrophenyl)naphthalene-1-amine

41

3.9 Characterization Techniques 41

3.9.a FT-IR

CHAPTER 4 : Findings &Conclusions 43

4.1 Conclusions 44

4.2 References

ANNEXURE

46

48

5

CHAPTER 1

INTRODUCTION

6

THEORY OF LINEAR AND NONLINEAR OPTICS

Linear and nonlinear optics covers a variety of phenomena involving the interaction of

light with matter. The constantly growing application of optics in technology,

telecommunication, medicine, etc. demanding detailed theoretical modeling, has opened new

fields for theoretical study. Understanding both the linear and nonlinear optical properties of

solids requires a detailed quantum mechanical picture of how electrons move in these materials.

This is an important emerging area of theoretical science.

Most familiar optical processes are proportional to light intensity. But, since the

late1960’s a variety of exciting nonlinear (scaling as the second, third etc. order of the light

intensity) optical phenomena have been discovered experimentally using powerful lasers [1, 2].

These so called many photon effects (second, third, and even higher order harmonic and sum

frequency generation, optical rectification, etc.) have found numerous applications. The

theoretical description of the linear and nonlinear optical properties of solids requires both

convenient and correct formalism, and a detailed quantum mechanical description of the many-

particle systems.

1.1 LINEAR OPTICAL PROPERTIES

The various ways in which light interacts with matter are of immense practical interest

e.g. absorption, transmission, reflection, scattering or emission. These properties are energy

dependent. The study of optical properties of solids has proven to be a powerful tool in our

understanding of the electronic properties of materials. In particular structure, energy

dependence of the properties mentioned above is in an intricate way related to the band structure.

Information on energy eigenvalues and Eigen function is needed to calculate the frequency /

energy dependent optical properties. When light of sufficient energy shines on a material, it

induces transitions of electrons from occupied states (below Fermi Energy, EF) to unoccupied

states (above EF). Clearly a quantitative study of these transitions must provide some

understanding of the position of the initial and the final energy bands and symmetry of their

associated wave functions.

7

1.2 Nonlinear optical properties A material interacting with intense light of a laser beam responds in a “nonlinear

fashion”. Consequences of this are a number of peculiar phenomena, including the generation of

optical frequencies that are initially absent. This effect allows the production of laser light at

wavelengths normally unattainable by conventional laser techniques. So the applications of Non

Linear Optics (NLO) range from basic research to spectroscopy, telecommunications and

astronomy.

Second harmonic generation (SHG), in particular, corresponds to the appearance of a

frequency component in the laser beam that is exactly twice the input one. SHG has great

potential as a characterization tool for materials, because of its sensitivity to symmetry. Today

SHG is widely applied for studying the surfaces and interfaces. For materials with bulk inversion

symmetry, SHG is only allowed at surfaces and interfaces. This makes SHG a powerful surface

selective technique. In case of embedded interfaces this technique gains extra weight when an

intense laser is used which is capable of penetrating deep into the material and no direct contact

with the sample is needed. In the case of linear optical transitions, an electron absorbs a photon from the incoming

light and makes a transition to the next higher unoccupied allowed state. When this electron

relaxes it emits a photon of frequency less than or equal to the frequency of the incident light

(Figure 1.a). SHG on the other hand is a two-photon process where this excited electron absorbs

another photon of same frequency and makes a transition to reach another allowed state at higher

energy. This electron when falling back to its original state emits a photon of a frequency which

is two times that of the incident light (Figure1.b). This results in the frequency doubling in the

output.

Figure 1. Schematic representation of (a) linear optical transition and

(b) second harmonic generation

8

In order to extend the use of NLO for understanding the properties of surfaces and for

extracting maximal information from such measurements for non centro-symmetric materials, a

more quantitative theoretical analysis is required.

1.3 Density Functional Calculations Density functional calculations (often called density functional theory (DFT)

calculations) are, like ab initio and SE calculations, based on the Schrodinger equation.

However, unlike the other two methods, DFT does not calculate a wavefunction, but rather

derives the electron distribution (electron density function) directly. A functional is a

mathematical entity related to a function. Density functional calculations are usually faster than

ab initio, but slower than SE. DFT is relatively new (serious DFT computational chemistry starts

in 1980' s, while computational chemistry with the ab initio and SE approaches was being done

in the 1960s).

Density functional theory is based on the Hohenberg-Kohn theorems, which state that,

“The ground-state properties of an atom or molecule are determined by its electron density

function, and that a trial electron density must give an energy greater than or equal to the true

energy”. DFT is not variational - it can give an energy below the true energy.

In the Kohn-Sham approach the energy of a system is formulated as a deviation from the

energy of an idealized system with non-interacting electrons. The energy of the idealized system

can be calculated exactly since its wavefunction (in the Kohn-Sham approach wavefunctions and

orbitals were introduced as a mathematical convenience to get at the electron density) can be

represented exactly by a Slater determinant. The relatively small difference between the real

energy and the energy of the idealized system contains the exchange-correlation functional, the

only unknown term in the expression for the DFT energy; the approximation of this functional is

the main problem in DFT. From the energy equation, by minimizing the energy with respect to

the Kohn-Sham orbitals, the Kohn-Sham equations (KS equations) can be derived, analogously

to the HF equations. The molecular orbitals of the KS equations are expanded with basis

functions and matrix methods are used to iteratively find the energy, and to get a set of molecular

orbitals, the KS orbitals, which are qualitatively similar to the orbitals of wave function theory.

The most popular current DFT method is the LSDA (Local Spin Density Approximation)

gradient-corrected hybrid method which uses the B3LYP (Becke three parameter Lee-Yang-

9

Parr) functional. For homolytic dissociation, correlated methods (e.g. B3LYP, pBP/DN* and

MP2) are vastly better than HF-level calculations; these methods also tend to give fairly good

activation barriers. DFT gives reasonable IR frequencies and intensities, comparable to those

from MP2 calculations. Dipole moments from DFT appear to be more accurate than those from

MP2. Time-dependent DFT (TDDFT) is the best method for calculating UV spectra reasonably

quickly. DFT is said to be better than HF (but not as good as MP2) for calculating NMR spectra.

1.4 Basis Sets An approximate wavefunction (eg. a Slater determinant) can be made up from MO’s

which are themselves approximated by atomic orbitals (LCAO). The AO’s are in turn

constructed from combinations of basis functions.

Basis functions AO’s MO’s Wave function

The list of all basis functions used in a calculation is called basis set.

The basis function model all the possible ways that electrons behave in a molecule. We should

include enough functions to model the orbital properly.

A basis set is a set of mathematical functions (basis functions), linear combinations of

which yield molecular orbitals. The functions are usually, but not invariably, centered on atomic

nuclei. Approximating molecular orbitals as linear combinations of basis functions is usually

called the LCAO or linear combination of atomic orbitals approach, although the functions are

not necessarily conventional atomic orbitals: they can be any set of mathematical functions that

are convenient to manipulate and which in linear combination give useful representations of

MOs. With this reservation, LCAO is a useful acronym. Physically, several (usually) basis

functions describe the electron distribution around an atom and combining atomic basis functions

yields the electron distribution in the molecule as a whole.

The electron distribution around an atom can be represented in several ways. Hydrogen-

like functions based on solutions of the Schrodinger equation for the hydrogen atom, polynomial

functions with adjustable parameters, Slater functions, and Gaussian functions have all been

used. Of these, Slater functions (STOs) and Gaussian functions (GTOs) are mathematically the

simplest, and it is these that are currently used as the basis functions in molecular calculations.

Slater functions are used in semi-empirical calculations. Modern molecular ab initio programs

employ Gaussian functions.

10

Slater Type Orbitals (STO) defined as,

Gaussian Type Orbitals (GTO) defined as,

where the radial part of the function, N is the

normalization factor, n is principal quantum number, is the angular part (spherical

harmonics), and Slater and Gaussian functions are usually characterized by parameters

designated ζ (zeta) and α, respectively.

Exponent ζ determines how fast or slow the basis function decays away from the atom.

Big ζ = fast decay = function close to nucleus; small ζ = slow decay = function far from nucleus.

The GTF’s have zero slope and no cusp at the nucleus. So GTF’s have problems

representing the proper behavior near the nucleus. GTF’s fall off too rapidly away from the

nucleus and the “tail” of the wave function is consequently represented poorly.

These problems can be solved by adding together several primitive Gaussians, called a

contraction, with different exponents and coefficients into one basis function to approximate the

shape.

1.4. a. Minimal Basis set

This basis set consists of one function each for the core orbitals and valence orbitals (whether

occupied or not).

Hydrogen 1s = one basis function; Fluorine 1s + 2s +2px + 2py + 2pz = five basis functions.

Carbon 1s + 2s +2px + 2py + 2pz = five basis functions. Unoccupied valence p orbital also

counted.

Iron 1s, 2s, 2px, 2py, 2pz, 3s, 3px, 3py, 3pz, 3dxy, 3dxz, 3dyz, 3dx2, 3dy2, 3dz2, 4s,

4px,4py,4pz = 19 basis functions.

For example, “STO-3G” is short-hand for a minimal basis set in which each basis function is a

contraction of three primitive Gaussians. The minimal basis sets are good for rough and quick

calculations, but are not very accurate.

11

1.4. b. Multi zeta Basis sets: To overcome the deficiencies of the minimal basis set other basis

sets have been developed.

• Double zeta basis sets: These have twice the number of functions for each

orbital. Thus hydrogen would have two functions, carbon and oxygen 10

functions each.

• Triple zeta basis sets have thrice the number of functions compared to minimal

basis set.

• Split valence basis set developed by Pople have single function for the core, the

valence functions are split into double zeta or triple zeta type.

For example, “6-31G” basis set for fluorine: 1s orbital described by 6 primitive Gaussians

contracted to one basis function, One set of 2s and 2p orbitals described by contraction of 3

primitive Gaussians, One set of 2s and 2p orbitals described by 1primitive Gaussian That is 1

function for the core + 2 functions each for the valence 2s, 2px, 2py and 2pz orbitals. i.e. 9

functions after contraction.

6-311G means one basis function each for the core orbitals and three basis functions each for the

valence orbitals with contractions of 6,3 ,1 and 1 primitives respectively.

• Polarisation functions are functions of higher angular momentum used to account for

the polarization of atoms that occurs when forming chemical bonds. Usually p functions

are used to polarises electrons, d functions to polarise p electrons and f functions to

polarise d electrons.

e.g. p functions for H or d functions for carbon

The notation 6-31G(d) (or 6-31G*) implies a 6-31G basis set to which a set of

polarization functions added to heavier atoms (non hydrogen atoms). The notation 6-

31G(d,p) (or 6-31G**) implies a 6-31G basis set to which a set of d polarization

functions added to heavier atoms and a set of p functions on hydrogen atom.

• Diffuse functions are polarisation functions which have a small exponent to describe the

electron density away from the nucleus (eg for anions and weakly bonded molecules).

They are indicated by a + symbol in the notation. Eg. 6-31++G(d) includes a set of

polarisation functions on heavy atoms and hydrogen. The choice of the basis set is

dependent on the problem being considered and the availability of computational

resources.

12

Nonlinear optical (NLO) materials play a pivotal role in the future evolution of nonlinear

optics in general and have a great impact on information technology and industrial applications.

The understanding of the polarization mechanism and their relation to structural characteristics

of the materials has been improved. So the goal is to find and develop materials presenting large

nonlinearities. Last decade witnessed the development of new nonlinear optical materials of

inorganic, organic and semi-organic types. Organic nonlinear optical materials have potentially

high nonlinearities and rapid response [3]. They offer high degree of synthetic flexibility to tailor

their optical properties through structural modification. Organic molecule possessing a

conjugated system with a strong π-electron delocalization can have a large optical nonlinearity.

The delocalization of the π-electrons can be further enhanced by the addition of donor and

accepter groups at the opposite ends of the conjugated system. The strong charge transfer

between such groups operating across the entire extended system markedly adds to the optical

nonlinearity of the structure [4].

The polarizability of naphthalene containing systems has been extensively studied with

different theoretical methods and is found to have good nonlinear response. An attractive method

to modulate electron density distribution in this conjugated system is the direct incorporation of

functional groups (spacers) into its backbone. Such studies are done on conjugated oligomers and

polymers [5, 6]. But donor-acceptor systems containing naphthalene incorporated with spacer

groups in the backbone are largely unexplored.

The principal aim of the project is to undertake an exhaustive theoretical investigation on

the structural, electronic and dynamic properties of naphthalene system linked to nitrophenyl

Group, incorporated with spacer groups into its backbone. The molecules with beneficial

properties can be developed into NLO materials having potential applications in the

optoelectronic devices of telecommunications, information storage, optical switching and

photovoltaic devices like solar cells. We propose to investigate molecules in which naphthalene

group is connected to dinitro and mono-nitrophenyl groups in which the liking groups are

saturated carbon chain.

13

1.5 OBJECTIVES

DFT studies on the electronic transitions of N-[3-(Naphthalene-1-yloxy)butyl]-2,4-

dinitroaniline, N-[3-(Naphthalene-1-yloxy)butyl]-4-nitroaniline, and their azanaphthalene

derivatives.

DFT studies on the Non Linear Optical Properties of N-[3-(Naphthalene-1-yloxy)butyl]-

2,4-dinitroaniline, N-[3-(Naphthalene-1-yloxy)butyl]-4-nitroaniline, and their

azanaphthalene derivatives and their structural relationships.

DFT studies on the electronic transitions of N-[3-(Quinoline-1-yloxy)butyl]-2,4-

dinitroaniline , N-[3-(Quinoline-1-yloxy)butyl]-4-nitroaniline, and their position isomers.

DFT studies on the Non Linear Optical Properties of N-[3-(Quinoline-1-yloxy)butyl]-2,4-

dinitroaniline , N-[3-(Quinoline-1-yloxy)butyl]-4-nitroaniline, and their position isomers

DFT studies on the electronic transitions of N-[(Naphthalen-5-yl)methyl]-4

nitrobenzamine and N-[(Naphthalen-5-yl)methyl]-2,4 dinitrobenzamine.

DFT studies on the Non Linear Optical Properties of N-[(Naphthalen-5-yl)methyl]-4-

nitrobenzamine N-[(Naphthalen-5-yl)methyl]-2,4 dinitrobenzamine.

DFT studies on the electronic transitions of N-(4-Nitrophenyl)naphthalene-1-amine and

N-(2,4-dinitrophenyl)naphthalene-1-amine

DFT studies on the Non Linear Optical Properties of N-(4-Nitrophenyl)naphthalene-1-

amine and N-(2,4-dinitrophenyl)naphthalene-1-amine

Synthesis and characterization of N-(2,4-dinitrophenyl)naphthalene-1-amine.

14

CHAPTER 2

EXPERIMENTAL SECTION

15

2.1 Computational Details

Gaussian 09 software package was used for DFT calculation and calculations were

performed at B3LYP/6-31G(d,p) level. The ground state structures were optimized and

frequency calculations were performed to ensure that the optimized structures are minima in the

potential energy surface. HOMO and LUMO for all the molecules are identified. Gauss View 5

software was used for generating the input file and visualization of the results. The calculation

were done using S20D300 workstation computer equipped with Intel 7 core processor and 24 GB

RAM and Microsoft Windows as the operating system. Electric dipole moment, linear

polarizability and first hyperpolarizability tensor components for the studied compounds were

calculated by DFT approach which is currently one of the ultimate procedure for obtaining

numerically accurate NLO response.

2.2 Chemicals

1-Naphthylamine, 1-Fluoro-2,4-Dinitrobenzene and acetonitrile were purchased from Merck,

NH2

1-Naphthylamine NO2

NO2

F

1-Fluoro-2,4-Dinitrobenzene

2.3. Synthesis of N-(2, 4-dinitrophenyl)naphthalene-1-amine

Synthesis is based on the following equation.

NH2

NO2

NO2

F

+NaHCO3Acetonitrile

HN NO2

NO2

16

1 mol of 1-Naphthylamine(1.42 g) and 1 mol of 1-Fluoro-2,4-Dinitrobenzene (1 g) were taken in

250 ml RB flask.25 ml acetonitrile is added to it. The reaction mixture is refluxed at 80˚C for 10

hours. After refluxing, the reaction mixture is added to ice cold water. Reaction completion is

confirmed by TLC. N-(2,4-dinitrophenyl)naphthalene-1-amine is purified by Column separation.

Its formation is confirmed by FT-IR Spectrum.

2.4 Characterization Techniques

FT-IR: FT-IR spectra were recorded in the transmission mode using KBr pellets on Perkin

Elmer spectrometer operating at 4 cm-1 resolution at a range of 750 cm-1 to 4000 cm-1.

17

CHAPTER 3 RESULTS AND DISCUSSIONS

18

3.1 DFT studies on the electronic transitions of N-[3-(Naphthalene-1-yloxy)butyl]-2,4-dinitroaniline, N-[3-(Naphthalene-1-yloxy)butyl]-4-nitroaniline, and their azanaphthalene derivatives

The studied molecules are presented in Table 1-2.The study involves geometry optimization of the molecules, identifying its frontier molecular orbitals and energy gap. Electronic transitions of the following molecules are also discussed.

Figure 2. Schematic representation of naphthalene, quinoline, quinazoline, triaza naphthalene and tetraazanaphthalene derivatives linked to mononitrophenyl

R5

R8

R6

R7

R3

R2

R4

R1

O

CH3

NH

N+

O-

O Table 1. Structure of naphthalene, quinoline, quinazoline, triazanaphthalene and

tetraazanaphthalene derivatives linked to mononitrophenyl

No R1 R2 R3 R4 R5 R6 R7 R8 Name

1 C C C C C C C C N-[3-(Naphthalene-1-yloxy)butyl]-4-nitroaniline

2 C C C N C C C C N-[3-(Quinoline-4-yloxy)butyl]-4-nitroaniline

3 C N C N C C C C N-[3-(Quinazoline-1-yloxy)butyl]-4-nitroaniline

4 C N C N N C C C N-[3-(2,4,5TriazaNaphthalene-1-yloxy)butyl]-4-nitroaniline

5 C N C N N C N C N-[3-(2,4,5,7 TetraazaNaphthalene-1-yloxy)butyl]-4-nitroaniline

19

Figure 2. Schematic representation of naphthalene, quinoline, quinazoline, triazanaphthalene and tetraazanaphthalene derivatives linked to dinitrophenyl

R5

R8

R6

R7

R3

R2

R4

R1

O

CH3

NH

N+

O-

O

N+

O-


tetraazanaphthalene derivatives linked to dinitrophenyl No R1 R2 R3 R4 R5 R6 R7 R8 Name 6 C C C C C C C C N-[3-(Naphthalene-1-yloxy)butyl]-2,4-dinitro

aniline 7 C C C N C C C C N-[3-(Quinoline-1-yloxy)butyl]-2,4-dinitro

aniline 8 C N C N C C C C N-[3-(Quinazoline-1-yloxy)butyl]-2,4-dinitro

aniline 9 C N C N N C C C N-[3-(2,4,5TriazaNaphthalene-1-yloxy)butyl]-

2,4-dinitroaniline 10 C N C N N C N C N-[3-(2,4,5,7 TetraazaNaphthalene-1-yloxy)

butyl]-2,4-dinitroaniline

20

3.1. a Geometry Optimization Several conformational isomeric cisoid and transoid structures of compound 1-10 were

optimized at B3LYP/6-31G (d,p) level. The lowest energy structures will be equilibrium

geometry of the molecules. The optimized molecular geometry (Fig.1-10) represents an isolated

molecule under ideal conditions with a stationary point at the potential energy surface. The

convergence was confirmed by observing no imaginary vibrational frequencies. All the

compounds in Table 1-2 show cisoid confirmation.

Table 3. Total energy and HOMO-LUMO gaps of compounds 1-5

Compound Total Energy Difference HOMO LUMO HLG

Hartrees kJ/Mol Hartrees Hartrees Hartrees eV 1

Cisoid

-1108.904369

10.75

-0.21101

-0.09895

0.11206

3.04

Transoid

-1108.908464

-0.20422

-0.07029

0.10397

3.64

2

Cisoid

-1124.962679

7.31

-0.22245

-0.07150

0.15095

4.11

Transoid

-1124.959894

-0.22341

-0.07283

0.15058

4.09

3

Cisoid

-1141.027722

6.14

-0.22071

-0.06992

0.1507

4.10

Transoid

-1141.025385

-0.22270

-0.07122

0.15148

4.12

4

Cisoid

-1157.07247

5.48

-0.22343

-0.07484

0.14859

4.04

Transoid

-1157.070381

-0.22519

-0.07327

0.15192

4.13

5

Cisoid

-1173.120091

6.04

-0.22564

-0.08870

0.13694

3.72

Transoid

-1173.117790

-0.22722

-0.08589

0.14133

3.85

21



Hartrees KJ/Mol Hartrees Hartrees Hartrees eV

1 Cisoid -1313..40761

8.77 -0.21101 -0.09895 0.11206 3.04

Transoid -1313.404273 -0.20722 -0.10325 0.10397 2.83

2 Cisoid -1329.456685

3.17 -0.23054 -0.10292 0.1276 3.47

Transoid -1329.455476 -0.22671 -0.10588 0.1208 3.29

3 Cisoid -1345.522103

2.66 -0.24403 -0.10254 0.1415 3.85

Transoid -1345.521089 -0.24202 -0.10410 0.1379 3.75

4 Cisoid -1361.56655

1.68 -0.24721 -0.10526 0.1419 3.86

Transoid -1361.565912 -0.24870 -0.10621 0.1425 3.87

5 Cisoid -1377.613794

3.8 -0.24817 -0.10589 0.1423 3.87

Transoid -1377.612347 -0.24805 -0.1029 0.1452 3.95

From Tables 3 and 4, it is evident that all the compounds in Table 1-2 show cisoid

confirmation. The geometries were fully optimized without any constraint with the help of

analytical gradient procedure implemented within Gaussian 09 program. All the parameters were

allowed to relax and all the calculations converged to an optimized geometry which corresponds

to a true energy minimum revealed by the lack of imaginary values in the frequency calculations.

Their optimized structure and structures of Frontier Molecular Orbitals (HOMO-LUMO) are

listed in Tables 5 and 6.

Their study demonstrated that there are significant differences in the structure of these

compounds related to the geometry of the naphthalene or azanaphthalene group. These

compounds may be divided into two groups: the first group, naphthalene or azanaphthalene, is

coplanar with spacer group. The second group, nitrophenyl, is twisted with respect to the spacer.

Theoretically, the torsional angles between the planes of the donor and acceptor subunits are

calculated. Also the optimized structure reveals that naphthalene/azanaphthalene linked to

mononitrophenyl are having more delocalization than naphthalene /azanaphthalene linked to

dinitrophenyl group. Effective distance between two rings in all 10 components were estimated

22

which is enlisted in Table 9. From this table, we can understand that effective distance between

two rings for mononitro derivatives were larger than dinitro derivatives. It reveals that mononitro

derivatives are having more delocalization than dinitro derivatives.

Table 5. Optmised structure of compound 1-10 Optimized structure of the aforementioned compounds are listed in Table 5.

23

Compound 1

Compound 6

Compound 2

Compound 7

Compound 3

Compound 8

Compound 4

Compound 9

Compound 5

Compound 10

24

Table 6. HOMO-LUMO Orbitals of compound 1-10

Compound HOMO Orbital LUMO Orbital

1

2

3

4

5

6

25

7

8

9

10

DFT and TDDFT calculations were performed on the 10 molecule which contain an

electron donor and electron acceptor which are linked together by saturated carbon chain. The

most stable conformations are cisoid confirmation for all ten compounds. The electronic

excitation occurs by the transfer of an electron from the HOMO or HOMO-1 orbital to LUMO

+1 orbital in all the ten compounds. The HOMO-LUMO gaps of the most stable conformations

of the ten compounds are close. The emission takes place by the transfer of an electron to the

LUMO orbital.

3.2. DFT studies on the Non Linear Optical Properties of the above molecule and their structural relationships.

The performance of various DFT functional and of basis sets in hyperpolarizability

calculations have been extensively studied for organic NLO materials [7-10]. The nonlinear

26

optical properties of donor acceptor derivatives of naphthalene and azanaphthalenes were

computed for different approximations of exchange and correlations because the quality of

approximation might have an important effect in DFT for such hydrogen-bonded systems [11].

BPV86, which uses Perdew’s 1986 functional with local correlation replaced by that which was

suggested Vosko et al. (VWN)[12-14]. Becke’s three parameter exchange functional and the

gradient corrected functional of Lee, Yang and Parr, B3LYP [12, 15, 16] and LSDA were used in

this study. Accurate calculation of nonlinear optical properties requires the use of extended basis

sets and a high level of theory. In particular, these basis sets have to include d and p polarization

functions together with s and p diffuse functions. In the present work, the 6-31G(d, p) [17-19]

basis set was chosen for calculation of static polarizability,

The nonlinear optical response of an isolated molecule in an electric field Ei can be presented as

a Taylor series expansion of the total dipole moment, μtot, induced by the field:

0

( ) ( )

1 1 .........,2! 3!

E E

E E E E E E

λ λ

λ λ λσ σ λσν σ ν λσνρ σ ν ρ

µ ψ µ ψ

µ µ α β γ

∧

=

= + + + +

Where, αis the linear polarizability, μ0 the permanent dipole moment and βis the first

hyperpolarizability tensor components. The isotropic (or average) linear polarizability and

anisotropy of polarizability is defined as [20]:

Isotropic linear Polarizability, 13 ( )xx yy zzα α α α= + +

Anisotropic linear Polarizability, 122 2 21

2 [( ) ( ) ( ) ]xx yy xx zz yy zzα α α α α α α∆ = − + − + −

The complete equation for calculating the total static first hyperpolarizability magnitude of

Gaussian output is given as follows [21]

First order Hyperpolarizability, 1

22 2 2[( ) ( ) ( ) ]tot xxx xyy xzz yyy yzz yxx zzz zxx zyyβ β β β β β β β β β= + + + + + + + +

The study involves the initial determination of static polarizabilities and hyperpolarizibilities in

the gas phase.

27

Naphthalene/ Azanaphthalene linked to mononitrophenyl ring

Nonlinear optical properties are calculated at DFT level using 6-31G (d, p) basis set using 3

hybrid functionals like B3LYP, BPV86 and LSDA. The calculated dipole moment, static mean

polarizabilities, anisotropy of polarizabilities and total first hyperpolarizibilities of the studied

compounds (1-5) are listed in Table 7a,7b,7c.and compounds 6-10 are enlisted in Table 7d,7e,7f.

Table 7a. NLO Properties of Naphthalene/ Azanaphthalene linked to mononitrophenyl ring using B3LYP

Compound μ ˂α˃ a.u Δα a.u βtot a.u. 1 7.68 246.89 209.43 2026.33 2 5.47 243.02 283.31 2339.59 3 7.56 237.98 275.56 2386.48 4 6.67 232.69 268.37 2306.04 5 5.68 225.93 186.68 1963.41

Table 7b. NLO Properties of Naphthalene/ Azanaphthalene linked to mononitrophenyl ring using BPV86


Table 7c. NLO Properties of Naphthalene/ Azanaphthalene linked to mononitrophenyl ring using LSDA


28

Table 7d. NLO Properties of Naphthalene/ Azanaphthalene linked to dinitrophenyl ring using B3LYP

Compound μ ˂α˃ a.u Δα a.u βtot a.u.

6 7.44 257.07 138.60 1467.67

7 7.05 257.86 236.46 1435.66

8 6.27 252.84 237.53 1528.13

9 5.56 247.75 229.99 1576.54

10 6.86 242.14 225.76 1543.95

Table 7e. NLO Properties of Naphthalene/ Azanaphthalene linked to dinitrophenyl ring using BPV86


6 7.47 265.89 148.78 1579.02

7 7.03 267.38 250.26 1681.89

8 6.25 262.51 251.86 1856.31

9 5.63 257.42 244.099 1896.38

10 6.92 251.77 240.10 1820.16

Table 7f. NLO Properties of Naphthalene/ Azanaphthalene linked to dinitrophenyl ring using LSDA


6 7.5835 266.34 150.15 1716.427

7 7.1259 268.01 252.03 1696.445

8 6.3503 263.18 253.72 1969.049

9 5.6991 258.07 245.89 2000.946

10 7.0256 252.45 241.98 1909.016

The discussion will be focused mostly on the first hyperpolarizability because the main objective of this work is to describe a general mechanism for obtaining large first-order optical nonlinearities in substituted naphthalene and azanaphthalene derivatives.

29

Graph 1. Comparison of first hyperpolarizability for compounds 1-5

2 4

2400

3200

4000

hype

rpol

arizi

bility

COMPOUNDS

LSDA BPV86 B3LYP

Graph 2. Comparison of first hyperpolarizability for compounds 6-10

1 2 3 4 51400

1500

1600

1700

1800

1900

2000

Hype

rpol

arizi

biliti

es

compounds

B3LYP BPV86 LSDA

In particular, the results of the calculations showed that the magnitudes of hyperpolarizibilities

are mainly dependent on the degree of electron delocalization between the two rings. Optical

response properties are governed by the increasing of both conjugation length and strength of

donor and acceptor groups. Also, the nitrogen numbers, planarity of the rings with spacer and

30

positions on the naphthalene are very important for nonlinearity of the title molecules.

Theoretically, the torsional angles between the planes of the donor and acceptor subunits are

calculated. Angle between C11-O1-C7-C8 determines the planarity of naphthalene ring with

spacer. Also the distance between C7-C15 is measured. They are shown in Figure 3-4.The

torsional angles and effective distance between two rings are enlisted in Table 8.

Figure 4. Naphthalene/Azanaphthalene linked to mononitrophenyl ring

31

Figure 5. Naphthalene/Azanaphthalene linked to dinitrophenyl ring

Table 8. Comparison of first hyperpolarizability for compounds 1-10 using B3LYP, BPV86 and LSDA and some selected geometrical parameters. β (B3LYP) β (BPV86) β (LSDA) C7-C15 (Å) C11-O1-C7-C8 (˚)

1 2026.33 2223.519 2271.065 6.89 2.434

2 2339.597 2536.114 2565.476 6.47 1.434

3 2386.487 2564.504 2599.997 6.433 1.280

4 2306.046 2474.841 2499.029 6.435 1.679

5 1963.409 1948.879 1938.155 6.434 2.884

6 1467.674 1579.016 1716.427 4.503 1.273

7 1435.662 1681.891 1696.445 5.779 3.277

8 1528.128 1856.31 1969.049 5.891 0.900

9 1576.539 1896.384 2000.946 5.924 0.692

10 1543.95 1820.155 1909.016 5.979 0.978

32

From this table, it is evident that the effective distance between two rings for mononitro

derivatives are larger than dinitro derivatives. As the effective distance increases, it is believed

that the extent of delocalization increases. So mononitro compounds are having large β values

than dinitro compounds. Addition of nitrogen on naphthalene changes the torsional angle

between the two units. However in all 10 compounds, naphthalene ring remains coplanar with

the spacer group. Among 10 selected compounds, compound no.3 is having highest β.This can

be attributed to its large delocalization and coplanarity of the ring with the spacer group.

3.3 DFT studies on the electronic transitions of N-[3-(Quinoline-1-yloxy)butyl]-2,4-dinitroaniline, N-[3-(Quinoline-1-yloxy)butyl]-4-nitroaniline, and their position isomers

The studied molecules are presented in Table 10-11.The study involves geometry optimization of

the molecules, identifying its frontier molecular orbitals and energy gap. Electronic transitions of

the following molecules are also discussed.

Figure 6. Schematic representation of naphthalene, quinoline, quinazoline, triazanaphthalene and tetraazanaphthalene derivatives linked to mononitrophenyl

R5

R8

R6

R7

R3

R2

R4

R1

O

CH3

NH

N+

O-

O

33

Table 9. Structure of naphthalene, quinoline, quinazoline, triazanaphthalene and tetraazanaphthalene derivatives linked to mononitrophenyl

No R1 R2 R3 R4 R5 R6 R7 R8 Name

1 C C C N C C C C N-[3-( Quinoline-2-yloxy)butyl]-4-nitroaniline

2 C C C N C C C C N-[3-(Quinoline-4-yloxy)butyl]-4-nitroaniline

3 C C C N C C C C N-[3-( Quinoline-6-yloxy)butyl]-4-nitroaniline

4 C C C N C C C C N-[3-( Quinoline-8-yloxy)butyl]-4-nitroaniline Figure 7. Schematic representation of naphthalene, quinoline, quinazoline,

triazanaphthalene and tetraazanaphthalene derivatives linked to dinitrophenyl

R5

R8

R6

R7

R3

R2

R4

R1

O

CH3

NH

N+

O-

O

N+

O-


tetraazanaphthalene derivatives linked to dinitrophenyl No R1 R2 R3 R4 R5 R6 R7 R8 Name 5 C C C N C C C C N-[3-( Quinoline-2-yloxy)butyl]-2,4-dinitroaniline 6 C C C N C C C C N-[3-(Quinoline-4-yloxy)butyl]- 2,4-dinitroaniline 7 C C C N C C C C N-[3-( Quinoline-6-yloxy)butyl]- 2,4-dinitroaniline 8 C C C N C C C C N-[3-( Quinoline-8-yloxy)butyl]- 2,4-dinitroaniline

34

3.3.a Geometry Optimization Several conformational isomeric cisoid and transoid structures of compound 1-10 were

optimized at B3LYP/6-31G(d,p) level. The lowest energy structures will be equilibrium

geometry of the molecules. The optimized molecular geometry (Fig.3-4) represents an isolated



compounds in Table 10-11 show cisoid confirmation.

Table 11a. Total energy and HOMO-LUMO gaps of compounds 1-4 Compound Total Energy Difference HOMO LUMO HLG

Hartrees KJ/Mol Hartrees Hartrees Hartrees ev

1

Cisoid -1124.976148 5.8

-0.21541 -0.06594 0.14947 4.07 Transoid -1124.9739 -0.21645 -0.06504 0.1547 4.21

2

Cisoid -1124.962679 7.31

-0.22245 -0.07150 0.15095 4.11 Transoid -1124.959894 -0.22341 -0.07283 0.15058 4.09

3

Cisoid -1124.960421 4.3 -0.21812 -0.06774 0.15038 4.09 Transoid -1124.95878 -0.21799 -0.06729 0.1507 4.10

4

Cisoid -1124.957051 5.9 -0.20848 -0.05984 0.14864 4.04 Transoid -1124.95480 -0.20831 -0.05691 0.1514 4.12

Table 11b. Total energy and HOMO-LUMO gaps of compounds 5-8 Compound Total Energy Difference HOMO LUMO HLG

Hartrees KJ/Mol Hartrees Hartrees Hartrees ev

1

Cisoid -1329.44298 0.92 -0.2236 -0.09166 0.1319 3.59

Transoid -1329.44263 -0.2231 -0.09159 0.1315 3.57

2

Cisoid -1329.456685 3.17 -0.23054 -0.10292 0.12762 3.47

Transoid -1329.455476 -0.22671 -0.10588 0.12083 3.28

3

Cisoid -1329.4374 4.72 -0.21241 -0.09585 0.11656 3.17

Transoid -1329.4356 -0.21238 -0.09568 0.1167 3.18

4

Cisoid -1329.46789 1.15

-0.22613 -0.07930 0.1468 3.99

Transoid -1329.46745 -0.22604 -0.07928 0.1467 4.00

35

Table 12. Optimized structure of compound 1-8

Compound 6

Compound 5

Compound 7

Compound 6

Compound 8

Compound 7

Compound 9

Compound 8

36


Compound HOMO Orbital LUMO Orbital 1

2

3

4

5

37

6

7

8

All the compounds show Cisoid confirmation and their energy gap between HOMO and LUMO is identified

38

3.3 DFT studies on the electronic transitions of N-[3-(Quinoline-1-yloxy)butyl]-2,4-dinitroaniline, N-[3-(Quinoline-1-yloxy)butyl]-4-nitroaniline, and their position isomers

The simplest polarizability, a, characterizes the ability of an electric field to distort the

electronic distribution of a molecule, that is, the molecule as a whole is perturbed. Consequently,

a change in the equilibrium nuclear geometry will take place as a result of the development of a

different potential-energy surface. The result would be a change in the vibrational and rotational

motions of the molecule.Clearly, an effect of such orientation redistribution cannot be ignored.

Higher order polarizabilities (hyperpolarizabilities β,γ. . .) which describe the non-linear

response of atoms and molecules are related to a wide range of phenomena from non-linear

optics to intermolecular forces, such as the stability of chemical bonds, as well as, the

conformation of molecules and molecular aggregates [23].

According to Buckingham [24] the polarizability tensors are formally defined by a Taylor

series expansion of the dipole moment of a molecule in the presence of an electric field E,

0

( ) ( )

1 1 .........,2! 3!

E E

E E E E E E

λ λ

λ λ λσ σ λσν σ ν λσνρ σ ν ρ

µ ψ µ ψ

µ µ α β γ

∧

=

= + + + +

Where, μ is the dipole polarizability, β is the hyperpolarizability and γ is the second

hyperpolarizability and so on.; These studies led to the fact that ab initio calculations of

polarizabilities and hyperpolarizabilities have become available through the strong theoretical

basis for analyzing molecular interactions. They made possible the determination of the elements

of these tensors from derivatives of the dipole moment with respect to the electric field. For

methods as the self-consistent field (SCF) for which the wave function obeys the Hellmann–

Feynman theorem, the derivative expression for the dipole is equivalent to the expectation value

[25]. Applying the rules of perturbation theory, α and β are determined from a knowledge of the

first-order wave function and γ from a knowledge of the second-order wave function. Thus they

may be calculated accurately at the self-consistent field level using the Hartree–Fock theory [26].

However, electron correlation can be very important [27, 28] depending on whether it is an open

or closed shell system [29,30].

39

Table 14a. NLO Properties of N-[3-(Quinoline-1-yloxy)butyl]-4-nitroaniline, and their position isomers


1 8.0318 245.8515 306.8861 2118.192

2 5.4716 243.0167 283.3157 2339.597

3 9.8753 245.9185 309.2144 1777.295

4 8.8968 239.2811 233.0332 1981.583

Table 14b. NLO Properties of N-[3-(Quinoline-1-yloxy)butyl]-2,4-dinitroaniline, and their position isomers


5 9.7377 262.4461 216.0226 1816.091

6 7.0527 257.8592 236.4552 1435.662

7 7.2650 260.5112 254.3742 2016.854

8 11.1655 259.1174 220.2316 1612.477

All the 8 compounds show high β values which means they can be developed into good NLO

materials.

40

3.5 DFT studies on the electronic transitions of N-[(Naphthalen-5-yl)methyl]-4-nitrobenzamine and N-[(Naphthalen-5-yl)methyl]-2,4 dinitrobenzamine

HN

NO2

N-[(Naphthalen-5-yl)methyl]-4 nitrobenzamin

HN

NO2

NO2

N-[(Naphthalen-5-yl)methyl]-2,4 dinitrobenzamine

3.5.1 Geometry Optimization

Several conformational isomeric cisoid and transoid structures of compound 1 and 2

were optimized at B3LYP/6-31G(d,p) level. The lowest energy structures will be equilibrium

geometry of the molecules. The optimized molecular geometry (Fig.8) represents an isolated



compounds in show cisoid confirmation.

Table 15. Total energy and HOMO-LUMO gaps of compounds 1-2 Compound Total Energy Difference HOMO LUMO HLG

Hartrees KJ/Mol Hartrees Hartrees Hartrees eV 1

Cisoid -915.83986 3.02 -0.21992 -0.06870 0.1512 4.11 Transoid -915.83871 -0.22202 -0.07044 0.1515 4.12

2

Cisoid -1120.34157 5.3

-0.23071 -0.09275 0.1379 3.75

Transoid -1120.322402 -0.23447 0.09085 0.1436 3.91

41


N-[(Naphthalen-5-yl)methyl]-4 nitrobenzamine

N-[(Naphthalen-5-yl)methyl]-2,4 dinitrobenzamine

N-[(Naphthalen-5-yl)methyl]-4 nitrobenzamine and N-[(Naphthalen-5-yl)methyl]-2,4

dinitrobenzamine shows cisoid conformation. Their frontier molecular orbitals are identified and

they are enlisted in Table 18.



2

42

3.6 DFT studies on the nonlinear optical properties of N-[(Naphthalen-5-yl)methyl]-4 nitrobenzamine and N-[(Naphthalen-5-yl)methyl]-2,4 dinitrobenzamine





motions of the molecule. Clearly, an effect of such orientation redistribution cannot be ignored.




conformation of molecules and molecular aggregates

Dipole moment, sotropic polarizability, anisotropic polarizability and hyper polarizability are

calculated using the aforementioned equation and were enlisted in Table 18.

Table 18: NLO properties of N-[(Naphthalen-5-yl)methyl]-4 nitrobenzamine and N-

[(Naphthalen-5-yl)methyl]-2,4 dinitrobenzamine

Compound μ ˂α˃ a.u Δα a.u βtot a.u. 1 7.3012 199.23 191.73 2518.743 2 8.0197 261.62 286.59 4748.619

N-[(Naphthalen-5-yl)methyl]-4 nitrobenzamine and N-[(Naphthalen-5-yl)methyl]-2,4

dinitrobenzamine show good nonlinear response.

43

3.7 DFT studies on the electronic transitions of N-(4-Nitrophenyl)naphthalene-1-amine and N-(2,4-dinitrophenyl)naphthalene-1-amine

HN

NO2

N-(4-Nitrophenyl)naphthalene-1-amine

HN

NO2

NO2

N-(2,4-dinitrophenyl) naphthalene-1-amine



Hartrees KJ/Mol Hartrees Hartrees Hartrees eV

1

Cisoid -876.55658 0.05 -0.21780 -0.07180 0.1460 3.97

Transoid -876.55656 -0.21781 -0.07179 0.1461 3.97

2

Cisoid -1081.05343 0.052 -0.22479 -0.10427 0.1205 3.28

Transoid -1081.05341 -0.22480 -0.10427 0.1205 3.28

N-(4-Nitrophenyl)naphthalene-1-amine and N-(2,4-dinitrophenyl)naphthalene-1-amine

show Cisoid conformation. Their HOMO-LUMO are identified.

44


N-(4-Nitrophenyl)naphthalene-1-amine

N-(2,4-dinitrophenyl)naphthalene-1-amine



2

45

3.8 DFT studies on the Nonlinear optical properties of N-(4-Nitrophenyl)naphthalene-1-amine and N-(2,4-dinitrophenyl)naphthalene-1-amine





motions of the molecule. Clearly, an effect of such orientation redistribution cannot be ignored.




conformation of molecules and molecular aggregates.

Dipole moment, isotropic polarizability, anisotropic polarizability and hyper polarizability are

calculated using 6-31++ G(d,p) at DFT level using the aforementioned equation and were

enlisted in Table 22.

Table 22. Nonlinear optical properties of N-(4-Nitrophenyl)naphthalene-1-amine and N-(2,4-dinitrophenyl)naphthalene-1-amine

Compound μ ˂α˃ a.u Δα a.u βtot a.u. 1 8.2300 240.43 207.95 2984.187 2 8.3970 263.27 221.64 3436.15

From the table, it is clear that N-(4-Nitrophenyl)naphthalene-1-amine and N-(2,4-dinitrophenyl)naphthalene-1-amine show good nonlinear response

3.9 Characterization Techniques

3.9.a FT-IR

FT-IR spectra were recorded in the transmission mode using KBr pellets on Perkin

Elmer spectrometer operating at 4 cm-1 resolution at a range of 750cm-1 to 4000cm-1.

N-(2,4-dinitrophenyl)naphthalene-1-amine was synthesized and it was confirmed by FT-IR

Spectrum.

46

Figure 4. IR spectrum of N-(2,4-dinitrophenyl)naphthalene-1-amine

IR interpretation

Frequency (cm-1) Assignments 3570-3200

1616

1384

Stretching of hydrogen bonded OH group Stretching of Naphthalene ring NO2 stretching vibration

4500 4000 3500 3000 2500 2000 1500 1000 50015

20

25

30

35

40

Tran

smitt

ance

(%)

wavenumber (cm-1)

47

CHAPTER 4

FINDINGS & CONCLUSIONS

48

4.1 Conclusions

• N-[3-(Naphthalene-1-yloxy)butyl]-4-nitroaniline, N-[3-(Quinoline-4-yloxy)butyl]-4-

nitroaniline, N-[3-(Quinazoline-1-yloxy)butyl]-4-nitroaniline, N-[3-(2,4,5TriazaNaphthalene-

1-yloxy)butyl]-4-nitroaniline, N-[3-(2,4,5,7 TetraazaNaphthalene-1-yloxy)butyl]-4-

nitroaniline were optimized at DFT level. All are showing Cisoid confirmation. Their

HOMO-LUMO is identified. Their nonlinear optical parameters are calculated using 6-31G

(d,p) basis set using B3LYP functional. All the compounds show high nonlinear optical

response. It is further confirmed by using BPV86 and LSDA method.

• N-[3-(Naphthalene-1-yloxy)butyl]-2,4-dinitroaniline, N-[3-(Quinoline-4-yloxy)butyl]- 2,4-

dinitroaniline, N-[3-(Quinazoline-1-yloxy)butyl]- 2,4-dinitroaniline, N-[3-

(2,4,5TriazaNaphthalene-1-yloxy)butyl]- 2,4-dinitroaniline, N-[3-(2,4,5,7

TetraazaNaphthalene-1-yloxy)butyl]- 2,4-dinitroaniline were optimized at DFT level. All are

showing Cisoid confirmation. Their HOMO-LUMO is identified. Their nonlinear optical

parameters are calculated using 6-31G (d,p) basis set using B3LYP functional. All the

compounds show high nonlinear optical response. It is further confirmed by using BPV86

and LSDA method.

• The aforementioned 10 compounds show high β values. It can be attributed to their small

Eg, large delocalization and coplanarity of the naphthalene ring with spacer group. High

delocalization is confirmed by finding effective distance between two rings and planarity of

the ring with spacer is confirmed by identifying the dihedral angle between spacer and

naphthalene ring.

• N-[3-(Quinoline-2-yloxy)butyl]-4-nitroaniline, N-[3-(Quinoline-4-yloxy)butyl]- 4-

nitroaniline, N-[3-(Quinoline-6-yloxy)butyl]- 4-nitroaniline, N-[3-(Quinoline-8-yloxy)butyl]-

4-nitroaniline are optimized at DFT level using B3LYP and 6-31 G(d,p). All compounds

show Cisoid conformation. Their frontier molecular orbitals are found out and Eg are

calculated. All NLO properties are found out and all the compounds show good nonlinear

response.

49

• N-[3-( Quinoline-2-yloxy)butyl]-2,4-dinitroaniline, N-[3-(Quinoline-4-yloxy)butyl]- 2,4-

dinitroaniline, N-[3-( Quinoline-6-yloxy)butyl]- 2,4-dinitroaniline, N-[3-( Quinoline-8-

yloxy)butyl]- 2,4-dinitroaniline are optimized at DFT level using B3LYP and 6-31 G(d,p).

All compounds show Cisoid conformation. Their frontier molecular orbitals are found out

and Eg are calculated. All NLO properties are found out and all the compounds show good

nonlinear response.

• N-[(Naphthalen-5-yl)methyl]-4 nitrobenzamine and N-[(Naphthalen-5-yl)methyl]-2,4

dinitrobenzamine are optimized at DFT level using B3LYP and 6-31++ G(d,p). All

compounds show Cisoid conformation. Their frontier molecular orbitals are found out and

Eg are calculated. All NLO properties are found out and all the compounds show good

nonlinear response.

• DFT studies on the electronic transitions of N-(4-Nitrophenyl)naphthalene-1-amine and N-

(2,4-dinitrophenyl)naphthalene-1-amine are done using B3LYP and 6-31++ G(d,p). All

compounds show Cisoid conformation. Their frontier molecular orbitals are found out and

Eg are calculated. All NLO properties are found out and all the compounds show good

nonlinear response.

• N-(2,4-dinitrophenyl)naphthalene-1-amine is synthesized using 1-naphtylamine and 1-

Fluoro-2,4-dinitrobenzene.Its formation is confirmed by FT-IR.

50

4.2 References

1. R. W. Boyd, “Nonlinear Optics”, Academic Press, INC., 1992, San Diego. Chapter 1.

2. E. G. Sauter, “Nonlinear Optics”, Tohn Wiley, 1996, New York.

3. C. Justin Raj, S. Dinakaran, S. Krishnan, B. Miltonboaz, R. Robert, S. Jerome Das, Opt.

Commun., 281(2008)2285..

4. Anadha Babu, A. S. Sreedhar, S. Venugopal Rao, P. Ramasamy, J. Cryst. Growth 311

(2009) 3461..

5. U. Gubler, S. Concilio, Applied Physics Letter, Volume 81,(13)

6. R.E Martin, J.A Wytko, F. Diederich, Chim. Acta, 82 (1999) 1470.

7. B. Champagne, E.A. Perpete and D. Jacquemin, J. Phys. Chem. A., 104(20) (2000) 4755.

8. E. Bogdan, A. Plaquet, L. Antonov,V. Rodriguez, L. Ducasse, B. Champagne and F.

Castet, J. Phys. Chem. C, 114(29) (2010) 12760.

9. D. Jacquemin, E.A. Perpete, I. Ciofini and C. Adamo, J. Comp. Chem., 29(6) (2008) 921.

10. D. Jacquemin, E.A. Perpete, G. Scalmani,M. J. Frisch, R. Kobayashi and C. Adamo, J.

Chem. Phys., 126(14) (2007) 14105.

11. D. R. Haman, Phys. Rev. B, 55 (1997) 10157.

12. .A.D. Becke., J. Chem. Phys., 98(7) (1993) 5648.

13. S.H. Vosko, L. Wilk and M. Nusair, Canadian J. Phys., 58-8 (1980) 1200.

14. J.P. Perdew, Phys. Rev. B, 33(12) (1986) 8822.

15. C. Lee, W. Yang and R.G. Parr, Phys. Rev. B, 37(2) (1988) 785.

16. J. P. Perdew, J. A. Chevary, S. H. Vosko,K. A. Jackson, M. R. Pederson, D. J. Singh

and C. Fiolhas, Phys. Rev. B, 46 (1992) 6671.

17. P. C. Hariharan and J. A. Pople, J. Chem. Phys., 27 (1974) 209.

51

18. R. Ditchfield, W.J. Hehre and J.A. Pople, J. Chem. Phys., 54 (1971) 724.

19. W. J. Hehre, R. Ditchfield and J.A. Pople , J. Chem. Phys., 56 (1972) 2257

20. H. Soscun, O. Castellano, Y. Bermudez,C. T. Mendoza, A. Marcano and Y. Alvarado, J.

Mol. Struct. (Theochem), 592 (2002) 19.

21. K.S. Thanthiriwatte and K.M.N. de Silva, J. Mol. Struct. (Theochem), 617 (2002) 169.

22. M. Nakano, I. Shigemoto, S. Yamada, K. Yamaguchi, J. Chem. Phys., 103 (1995) 4175.

23. A.D. Buckingham, Adv. Chem. Phys., 12 (1967) 107.

24. J.E. Rice, R.D. Amos, S.M. Colwell, N.C. Handy, J. Sanz, J. Chem. Phys., 93 (1990)

8828.

25. R.M. Stevens, R.M. Pitzer, W.N. Lipscomp, J. Chem. Phys., 38 (1963)550.

26. J.E. Rice, P.R. Taylor, T.J. Lee, J. Almlo¨ f, J. Chem. Phys., 94 (1991)4972.

27. T. Nakajima, K. Hirao, Chem. Lett., 30 (2001) 766.

28. G. Maroulis, Chem. Phys. Lett., 334 (2001) 207.

29. G. Maroulis, C. Pouchan, J. Phys. B, 36 (2003) 2011.

52

minor research project [12 mrp-1872/14-15/klmg016/ugc...

Documents