A DEPOLARIZED RAYLEIGH-SCATTERING STUDY OF CS2-BENZENE LIQUID-MIXTURES AND THE COMPARISON OF THE INTERACTION-INDUCED DYNAMICS WITH FAR-INFRARED

The low frequency Raman spectra of five different CS2-benzene liquid m ixtures and of the pure components are reported in the frequency range between -300 cm(-1) and +300 cm(-1). The collective dynamics are repr esented by at least two different time scales. The first one can be at tributed to slow fluctuations in the permanent polarizability anisotro py of the molecules with relaxation rates of the order of similar to 2 ps. The origin of the second one is attributed to the intermolecular pair interaction-induced polarizability anisotropies, which fluctuate on a faster time scale, with corresponding relaxation times of the ord er of similar to 0.2 ps. The collective times for all the mixtures are shown together with the corresponding time correlation functions. The results for the interaction induced profiles reveal an analogy to tho se obtained in the far infrared, indicating stronger intermolecular in teractions and the formation of CS2-benzene liquid ''transient cluster s'' in the mixtures. The absolute depolarized ratios are given togethe r with the static orientational factor (Z), which suggests a tendency for perpendicular orientation of neighbouring molecular axes in the mi xture.