Molecular Structure, Vibrational Assignments and Non-Linear Optical Properties of 4,4’ Dimethylaminocyanobiphenyl (DMACB) by DFT and &amp;lt;i&amp;gt;ab Initio&amp;lt;/i&amp;gt; HF Calculations

Nadia Benhalima,Charef Tabti

doi:10.4236/ampc.2015.57023

Abstract

In the present study, structural properties of 4,4’ dimethylaminocyanobiphenyl (DMACB) have been studied extensively by using ab initio Hartree Fock (HF) and density functional theory (DFT) employing B3LYP/B3PW91 exchange correlation levels of theory. The vibrational frequencies of DMACB in the ground state have been calculated by using Hartree Fock level and density functional method (B3LYP/B3PW91) with 6-31G(d, p), basis set. Nonlinear optical (NLO) behavior of the examined molecule is investigated by the determination of the electric dipole moment μ, the polarizability α, and the hyperpolarizability β by using the B3LYP/B3PW91 methods.

Highlights

Non linear optical (NLO) phenomena are of significance because they form the basis of the optical processing and data storage
density functional theory (DFT) was applied using the B3LYP which is the keyword for the hybrid functional [7], which is a linear combination of the gradient functional proposed by Becke [8] and Lee, Yang and Parr [9], together with the Hartree Fock local exchange function [10]
The geometries predicted by the Hartree Fock (HF) calculations are a little better than the DFT computations

Summary

Introduction

Non linear optical (NLO) phenomena are of significance because they form the basis of the optical processing and data storage. They are important in the development of the future generations of communication systems and computers, and much effort has been devoted to increasing the useful non linearity of optical mate-. How to cite this paper: Tabti, C. and Benhalima, N. (2015) Molecular Structure, Vibrational Assignments and Non-Linear Optical Properties of 4,4’ Dimethylaminocyanobiphenyl (DMACB) by DFT and ab Initio HF Calculations. For a material having useful and highly efficient nonlinear optical properties, the constituting molecules need first to exhibit large molecular hyperpolarizabilities, which are generally characterized by a highly extended π-conjugated chain with electron donor-acceptor pair at the ends (D-π-A). The electric dipole moment μ, the isotropic polarizability α and the first hyperpolarizability β of the title compound are calculated

Objectives

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Conclusion