Broad-band dielectric spectra and concentration-depended structural changes in aqueous solution of dimethyl sulfoxide

A model of structural and molecular-kinetic changes in dimethyl sulfoxide ( DMSO) solution is suggested. Results of dielectric measurements within micr owave and sub-millimeter ranges of wave lengths are interpreted. To do this , we applied a semi-phenomenological hybrid model (HM) to calculate the abs orption spectra and complex dielectric permittivity associated with librati ons (rotations) of electric dipoles in a rectangular box characterizing int ermolecular interactions in a condensed medium. In the suggested calculatio n procedure, we introduced one fraction of DMSO molecules and one or severa l fractions of water. For these fractions we determined HM parameters. In t he present work, changes in parameters of the molecular motion model are at tributed to manifestation of hydrophillic and hydrophobic hydration of DMSO molecules and to formation in solution of strong hydrogen bonds DMSO-H2O.