Osmium carbodithioato derivatives. Syntesis and spectroscopic studies

Several new dithiocarbamate complexes of osmium(III) and osmium(II) have been synthetized and characterized by i. r. and electronic spectra, magnetic susceptibilities and conductivity measurements. The dithio ligands show a bidentate behaviour in all the complexes. From the electronic absorption spectra the values of the ligand field parameters were determined; the nephelauxetic parameter is indicative of a strong covalency in the metal-ligand bond as confirmed by the Dq values. All the complexes of osmium (III) and osmium(II) were octahedral, distorted owing to the presence of two molecules of coordinated water the metal(II) derivatives; the room temperature magnetic susceptibility values show that the complexes are of low-spin type: the osmium(III) derivatives have one unpaired electron, while the osmium (II) ones were diamagnetic.