VIBRATIONAL DEPHASING OF LIQUID CARBONDISULFIDE INVESTIGATED BY PICOSECOND CARS

Using time-resolved CARS the dephasing rate 1/T2 of the nu-1 mode of CS2 is investigated in the neat liquid and in the solution of n-pentane. A large pressure effect (factor of less-than-or-equal-to 3) is reported for the range 0-4 kbar similar to spontaneous Raman results. A non-monotonic temperature dependence is reported for an extended interval of 160-450 K and explained by the contributions of vibration-translation and vibration-rotation coupling to 1/T2. Estimates of the intermolecular collision frequency from reorientation relaxational data lead to a phenomenological description of vibrational dephasing that accounts semi-quantitatively for the experimental data.