The isotropic Raman band of the C=O stretching mode of the acetophenone molecule has been recorded in a number of solvents of varying physicochemical properties. The experimental results suggest that dispersion forces are responsible for the observed isotropic frequency shift. The variation in the band shape parameters has been studied as a function of the hydrodynamic properties of the solvents. The effect of solvent viscosity on linewidth (Γiso) has been studied in detail. The concept of microviscosity is shown to account for the bandwidth of the isotropic component of the Raman band.
