Time-resolved coherent Stokes Raman spectroscopy (CSRS) of benzene

Abstract

Femtosecond time-resolved coherent Stokes Raman spectroscopy (CSRS) signals of benzene-h6, benzene-d6, and their 1 : 1 binary mixture are investigated at room temperature with two different polarization geometries. The reorientational correlation time of benzene as well as the vibrational dephasing time of the v1 ring-breathing mode have been measured precisely. Bohr frequency difference beats have been resolved between the v1 modes of 12C6H6 and 12C6H6 and 12C513CH6 protonated benzenes and the 12C6D6 and 12C513CD6 deuterated benzenes that are present at natural abundances in their neat liquids. There is no evidence for stochastic line broadening phenomena other than in their fast modulation limit even on the 100 fs time scale of these experiments.