Raman spectra of halogen-substituted methanes in the liquid state. 3—Temperature effects†

The effect of temperature on the peak positions, the isotropic and reorientational band widths and the depolarization ratios of the Raman bands for the totally symmetric vibrations of CHCl3, CH2Cl2, CH2Br2, CH3Br, CH3I and CD3I has been measured in the liquid state. The isotropic band width for a CX stretching vibration decreases with increasing temperature for molecule with only one CX bond, whereas it increases for a molecule with two or three equivalent CX bonds. The isotropic band width for the deformation vibrations decreases with increase in temperature. For all the bands, the depolarization ratios depend only slightly on temperature.