Role of Solvent on Absorption Frequencies of S=O Group of Dimethyl Sulfoxide in Binary Mixtures

The work is devoted to the study of preferential solvation of dimethyl sulfoxide in binary solvents by IR spectroscopy. The absorption frequencies of stretching vibrations of S=O group of dimethyl sulfoxide in mixtures of carbon tetrachloride with acetone, acetonitrile and nitromethane at different ratios of components were determined. Shifts of absorption frequencies of stretching vibrations of the S=O group of dimethyl sulfoxide (Δν_{pref. solv}) in binary solvents as a measure of preferential solvation were calculated. Solvation shells (x*) in binary solvents for the S=O group of dimethyl sulfoxide have been determined using absorption frequencies. The role of the second component of the binary mixture on the effects of preferential solvation and changes in solvation shell composition (x*) was discussed.