Vibrational spectra, molecular structure, NBO, UV, NMR, first order hyperpolarizability, analysis of 4-Methoxy-4′-Nitrobiphenyl by density functional theory

Abstract

In this study, geometrical optimization, spectroscopic analysis, electronic structure and nuclear magnetic resonance studies of 4-Methoxy-4′-Nitrobiphenyl (abbreviated as 4M4′NBPL) were investigated by utilizing HF and DFT/B3LYP with 6-31G(d,p) as basis set. The equilibrium geometry, vibrational wavenumbers and the first order hyperpolarizability of the 4M4′NBPL have been calculated with the help of density functional theory computations. The FT-IR and FT-Raman spectra were recorded in the region 4000–400cm−1 and 3500–50cm−1 respectively. Natural Bond Orbital (NBO) analysis is also used to explain the molecular stability. The UV–Vis absorption spectra of the title compound dissolved in chloroform were recorded in the range of 200–800cm−1. The HOMO–LUMO energy gap explains the charge interaction taking place within the molecule. Good correlation between the experimental 1H and 13C NMR chemical shifts in chloroform solution and calculated GIAO shielding tensors were found. The dipole moment, linear polarizability and first order hyperpolarizability values were also computed. The linear polarizability and first order hyperpolarizability of the studied molecule indicate that the compound is a good candidate of nonlinear optical materials. The chemical reactivity and thermodynamic properties of 4M4′NBPL at different temperature are calculated. In addition, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis were investigated using theoretical calculations.