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Z. Naturforsch. 67a, 210 – 216 (2012)
doi:10.5560/ZNA.2011-0067
Estimation of Configurational Probability and Phase Behaviour of N-n-undecyl-D-gluconamide having V-Shaped Conformation – A Molecular Simulation Approach
P. Lakshmi Praveen and Durga P. Ojha
Liquid Crystal Research Laboratory, Post-Graduate Department of Physics, Andhra Loyola College, Vijayawada-520 008, A.P., India
Received July 27, 2011 / revised October 24, 2011 / published online April 2, 2012
Reprint requests to: D. P. O.; E-mail: durga_ojha@hotmail.com
The present article deals with the configurational probabilities of a smectogen N-n-undecyl-D-gluconamide (GAM11). The complete neglect differential overlap (CNDO/2) method has been employed to compute the net atomic charge and atomic dipole moment components at each atomic center. The modified Rayleigh–Schrödinger 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 total interaction energy values obtained during different modes of molecular interactions have been used as input to calculate the configurational probability at room temperature (300 K), and smectic-isotropic transition temperature (429.7 K) using the Maxwell–Boltzmann formula. The various possible geometrical arrangements of molecular pairs have been considered. Further, an attempt has been made to explain the smectic behaviour of GAM11 in terms of their relative order based on the molecular parameters introduced in this paper.
Key words: N-n-Undecyl-D-Gluconamide; Smectogen; Molecular Rigidity.
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