Determination of Chlorine Vibrations in Dichlorobenzenes from Intensities and Polarizations of Their Raman Lines

摘要

Intensities and polarization properties of vibrations in which mainly chlorine atoms are participating, are investigated theoretically for the dichlorobenzenes. It is assumed that the change of polarizability in these vibrations is connected primarily with displacements of the chlorine atoms and that contributions from the individual atoms are additive. The Raman tensors belonging to the chlorine vibrations are then obtained by either adding or subtracting the single C&sngbnd;Cl contributions with reference to a chosen system of axes rigidly connected with the molecule. Intensity ratios were obtained for the symmetrical and unsymmetrical valence vibrations and deformation vibrations, respectively. Very small depolarization factors were found for lines representing symmetrical valence vibrations. For deformation vibrations the simplified theory gives complete depolarization for all allowed Raman lines. The results are discussed in connection with existing experimental data.