THE INTERMOLECULAR INTERACTION MECHANISMS IN LIQUID CS2 AT 295 AND 165 K PROBED WITH 2-DIMENSIONAL RAMAN-SPECTROSCOPY

Two-dimensional Raman spectroscopy is used to probe the intermolecular interaction dynamics of CS2 at 295 and 165 K. The influence of nonlin ear polarizability and liquid anharmonicity on the observable is discu ssed. It is found that the response at both temperatures is dominated by the nonlinear polarizability, which is most likely due to interacti on-induced effects. A model using three Brownian oscillators to repres ent the collective motions on three time scales is unable to reproduce the 295 K data. At low temperature, the model presumably works better as a result of the time-scale separation between the inertial and dif fusive dynamics. (C) 1998 Elsevier Science B.V. All rights reserved.