VIBRATIONAL DEPHASING IN BROMOCYCLOHEXANE - HOW TO SEPARATE CONTRIBUTIONS FROM DIFFERENT MECHANISMS

Raman and IR spectra of bromocyclohexane dissolved in methylcyclohexan e, methanol, 1-propanol and 2-propanol have been recorded. The isotrop ic 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 nu(1) rin g mode for the axial (804 cm(-1)) and the equatorial (811 cm(-1)) conf ormers have cm 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 depend ence for the C-Br stretching mode differ considerably from those obtai ned for the ring mode nu(1). To make this discrepancy clearer we have studied solvent effect on vibrational dynamics of bromocyclohexane by using various models of vibrational dephasing.