The Influence of Organic Solvents and Conformational Behavior of Mesogenic Compounds: A Computational Approach

Abstract

The role of organic solvents and conformational behavior of liquid crystalline disubstituted biphenylcyclohexanes (BCHs) of the general formula R-C₆H₁₀-C₆H₄-C₆H₄-X with R: C₃H₇; X: H (BCH30) and R: C₅H₁₁; X: CN (BCH5CN) have been reported 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 non-polar organic solvents, i.e., carbon tetrachloride (CCl₄) and chloroform (CHCl₃), at room temperature 300 K. It has been observed that the molecules show the remarkable behavior in the solvents. A comparison of stacked dimers between both the molecules suggests that the extension of the chain length, a recognizable segregation of dimers into a highly tilted layer structured, has been obtained for BCH5CN molecule.

Keywords:

• Liquid crystals
• non-polar solvents
• quantum chemistry

Acknowledgments

The financial support rendered by the DST, CSIR, UGC, New Delhi, and DAE-BRNS, Mumbai, India, is gratefully acknowledged.