Chlorocarbonyl Ru(III) complex with dimethyl sulfoxide: An ab initio studyof the electronic and geometrical structure and vibrational spectra of trans-[Ru(Me2SO)(CO)Cl-4](-)

The electronic structure of the DMSO (Me2SO) ligand coordinated to the plat inum group metal ions is studied. Structural parameters of the trans-[Ru(Me 2SO)(CO)Cl-4](-) complex anion are obtained by full geometry optimization, and characteristics of the vibrational spectrum are calculated using the ab initio force field. Our calculations are consistent with experimental evid ence that the S-O bond in the oxygen-coordinated Me2SO molecule is weakened . The fact of a small variation in the electron density on the donor oxygen atom in the complex in question in combination with a considerable total t ransfer of electron density from the DMSO ligand molecule as a whole is rat ionalized in terms of the concept of equalizing electronegativity upon the formation of metal-ligand bonds.