Thermodynamic and Ultraviolet Stabilities of Para-Azoxyanisole: A Nematic Liquid Crystal

Abstract

In this paper the optimization of ofpara-azoxyanisole (PAA) has been carried outwith the help of density functional theory, B3LYP functional and 6-31+G (d) basis set. The input geometry taken was crystallographic in nature. AM1 method was used to evaluate the dipole moment and atomic net charge at different atomic centres. The modified Rayleigh-Schrodinger perturbation theory was used to estimate the long-range intermolecular interactions with the help of multicentered-multipole expansion method. For short-range interactions, a potential function of '6-exp' has been considered. Next, Helmholtz free energy and configurational entropy have been calculated. Theinteraction energy values corresponding to orientationaland translational motions at room temperature (300K) and nematic-isotropic transition temperature (408K) during different molecular interaction modes has been used for such a calculation. These parameters have been used to analyze the thermodynamic stability of PAA. The absorption wavelengths of the molecule have been estimated in the Ultraviolet visible region by employing Discrete Fourier Transform (DFT). UV-Vis stability of the molecule has also been discussed.