RAMAN SPECTRAL STUDIES FOR SOLUTIONS OF DIMETHYL-SULFOXIDE IN THE S=O STRETCHING REGION

Raman spectra in the S=O stretching region are reported for solutions of dimethyl sulphoxide (DMSO) in carbon tetrachloride (CCl4), dichloromethane. (CH2Cl2), chloroform (CHCl3) and acetonitrile (CH3CN). The bands have been analysed qualitatively as a function of the concentration of DMSO with respect to the change in the shape and integrated intensities. Raman spectra of solutions of DMSO in binary mixtures of polar solvents and CCl4, keeping the concentration of DMSO constant and varying the concentration of polar solvent, show interesting regularities in the variation of the band shapes. In some cases the bands are further subjected to analysis such as second derivative, Fourier self deconvolution (FSD) and Gaussian band fitting for gaining further information on the band structures and the existence of different complexed species in solutions. The results are explained in terms of self-association of DMSO and its intermolecular interactions with polar solvents.