Molecular Crystals and Liquid Crystals, Vol.569, 24-32, 2012
Role of Oxygen and Effect of Solvents on Nematogens-A Computational Analysis
A comparative computational analysis on two nematogens, p-n-heptylbenzoic acid (7BAC), and p-n-heptyloxybenzoic acid (7OBAC) has been carried out with respect to the translational and orientational motions. The atomic net charge and dipole moment components at each atomic center have been evaluated using the complete neglect differential overlap (CNDO/2) method. The modified Rayleigh-Schrodinger perturbation theory with the multicentered-multipole expansion method has been employed to evaluate the long-range interactions, and a "6-exp." potential function has been assumed for the short-range interactions. The minimum energy configurations obtained during the different modes of interactions have been taken as input to calculate the configurational probability using the Maxwell-Boltzmann formula in nonpolar organic solvents, i.e., carbon tetrachloride (CCl4) and chloroform (CHCl3) at room temperature (300 K). The most stable configuration of pairing, during the stacking interactions, has been obtained for 7BAC in CCl4. Furthermore, an attempt has been made to analyze the role of oxygen and effect of solvents on nematogens at molecular level.