The effect of composition on the noncoincidence of the isotropic and anisotropic Raman frequencies and its intrepretation by means of a simple dielectric model

Abstract

The difference between the anisotropic and the isotropic frequencies of the C=O stretching bands of acetone, acetophenone, methylbenzoate, and dimethylformamide was measured in several mixtures of known dielectric constant. Its change with concentration can be explained by making the assumption that the interaction energy of the dissolved dipoles is described by the dielectric model of Onsager–Fröhlich over the whole composition range. The same model accounts for the change of the above difference in neat liquids with temperature.