Depolarized Rayleigh scattering and 13C NMR studies of anisotropic molecular reorientation of aromatic compounds in solution

Abstract

Measurements of reorientational relaxation times of simple aromatic compounds have been made by both depolarized Rayleigh light scattering and 13C NMR spin-lattice relaxation. Combination of the reorientation times determined by these techniques makes it possible to extract the reorientation times about the different molecular axes. The viscosity dependence of reorientation times about the individual molecular axes has been measured for benzene, mesitylene, toluene, and nitrobenzene. The viscosity dependence, which is highly anisotropic, is discussed in terms of a ``slip'' model of reorientational motion.