Contribution to the Raman Line Profile in Liquids from Molecular Reorientation

Abstract

The profiles of several Raman lines arising from nontotally symmetric molecular vibrations in liquid benzene and carbon tetrachloride were analyzed. That these lines have shown greater intensity in the wings than can be accounted for by a Raman process that involves molecular vibrations alone is interpreted as evidence for time-dependent reorientations of vibrationally excited molecules through small angles in the liquid phase. Data analysis on this basis indicates a weaker rotational coupling between molecules in the ground state than there is between vibrationally excited molecules and those in the ground state.