Odd-even effect in a homologous series of 4-n-alkylbenzoic acids: Role of anisotropic pair potential

Abstract

A computational analysis based on quantum mechanics has been carried out to determine the association energy of seven homologues of the 4-n-alkylbenzoic acid series (n = 3, 4, 5, 6, 7, 8, and 9), using the Rayleigh-Schrödinger perturbation method for various nearest neighbour configurations of interacting pairs. The net atomic charges and dipoles have been computed using the CNDO/2 method. An attempt is made to explain the odd-even effects at the molecular level on the basis of these results.