Infrared Spectra of Polar Diatomic Molecules in Quadrupolar Condensed Solvents

Publisher Website
Google Scholar
Abstract
The present paper is devoted to the computation of the infrared spectral properties of couples containing a polar and a quadrupolar molecule located at fixed distances which are permanently realized in condensed media. A study of the orientational quantum states of such couples using an asymptotic method is presented. This method is particularly suited when the angle dependent variation of the total interaction energy is large compared with the rotational energy of the free molecules. Then, a detailed quantitative description of the spectra of such couples is given and is compared to experimental data concerning the infrared spectra of dilute solutions of HCl in the solid, liquid, and highly compressed gases N2, CO, CO2 and CS2. The binary model used to build the theoretical spectra appears to be well suited to describe many detailed features of the experimental data. A discussion is then given to help in the understanding of why the concept of molecular couple used to approach the spectral properties of the condensed phases is apparently able to give a fairly consistent description of the observed profiles of the considered media.