Raman spectra of halogen‐substituted methanes in the liquid state. 2—Band widths of the totally symmetric vibration bands

The isotropic and anisotropic Raman band widths of the totally symmetric vibrations of halogen‐substituted methanes have been measured in the liquid state at room temperature. The isotropic CH and CD stretching vibration bands broaden with increasing molecular weight and this is qualitatively explained by the Fischer‐Laubereau dephasing model. The isotropic band widths of the deformation vibrations are correlated with the reorientational correlation times and are attributed to broadening due to interactions dependent on the orientation, such as the dipole–dipole interaction.