Rotational Diffusion of Spherical-Top Molecules in Liquids. II. Reorientation in Liquid Methane and Solutions of Methane in Liquid Noble Gases

Abstract

Numerical calculations of reorientational correlation functions and spectral densities for spherical‐top molecules in the extended rotational diffusion models are presented. The correlation functions obtained from Fourier transformation of the v₃ infrared band contours for CH₄ and CD₄, in pure liquid form and in dilute solutions in liquid noble gases, are compared with calculated correlation functions. This comparison suggests that rotational energy transfer is much more rapid in the neat liquid methanes than in liquid noble gases, and allows an estimate of the anisotropy of the intermolecular potential experienced by the methane molecules.