Effect of Non-Mesogenic Solvent on Molecular Conformations and Interactions of a Nematogen: A Probabilistic Approach

Abstract

A probabilistic approach has been carried out on molecular conformations and interactions of a monotropic nematogen 4-n-hexyl-N-(4-cyanophenyl) piperidine with respect to 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 method. The modified Rayleigh–Schrodinger perturbation theory along with the multicentered–multipole expansion method has been employed to evaluate the long-range intermolecular interactions, while a “6-exp” potential function has been assumed for short-range interactions. The interaction energy values obtained during the different modes of molecular interactions have been taken as input to calculate the configurational probability at room temperature (300 K). On the basis of stacking, in-plane, and terminal interaction energy calculations, all possible geometrical arrangements between the molecular pairs have been considered. Furthermore, the effect of a non-mesogenic solvent (benzene) on molecular conformations during different modes of interactions has been analyzed. The adopted framework provides valuable information on configurational freedom of a molecule that may be useful in understanding the mesomorphic behavior/transitions.

Keywords:

• Molecular conformations
• configurational probability
• nematogen

Acknowledgments

The financial support rendered by the Department of Science and Technology (DST), Council of Scientific and Industrial Research (CSIR), and University Grants Commission (UGC), New Delhi, India is gratefully acknowledged.