Vibrational dephasing in bromocyclohexane: how to separate contributions from different mechanisms Original Research Article

Raman and IR spectra of bromocyclohexane dissolved in methylcyclohexane, methanol, 1-propanol and 2-propanol have been recorded. The isotropic line widths of the CBr stretching mode for the axial (658 cm−1) and the equatorial (686 cm−1) conformers as well as of the ν1 ring mode for the axial (804 cm−1) and the equatorial (811 cm−1) conformers have been measured as a function of concentration. The ratio of integral Raman intensities and IR absorptions of the axial and the equatorial conformers, the band widths and their concentration dependence for the CBr stretching mode differ considerably from those obtained for the ring mode ν1. To make this discrepancy clearer we have studied solvent effect on vibrational dynamics of bromocyclohexane by using various models of vibrational dephasing.