The ultrafast dynamics of Liquid CBrCl3 studied with optical Kerr effect and Raman scattering

The ultrafast inter- and intramolecular dynamics of liquid CBrCl3 are studi ed with a femtosecond laser in a pump/probe optical Kerr experiment. The pr ompt part of the observed Kerr signal is found to comprise not just electro nic response but also coherent coupling. As reported in the literature, the weak and delayed part of the signal is attributed to three kinds of interm olecular dynamics: diffusive reorientation, polarizability distortion, and molecular libration with decay times, respectively, of 2ps, 500fs, and 190f s. Included in the delayed Kerr signal are long lasting oscillations which are ascribed to quantum interference involving four normal vibrations of th e molecule. By a careful fitting of both the time domain (Kerr) and frequen cy domain (Raman) data with existing theories the four vibrations are ident ified as v(2) = 422 cm(-1), v(3) = 246 cm(-1), v(5) = 295 cm(-1), and v(6) = 191 cm(-1), with dephasing times, 1.1ps, 1.7ps, 1 ps, and 1 ps, respectiv ely.