Magnetic and spectroscopic studies on copper(II) and chromium(III) complexes with sulfur chelating ligands

A number of complexes of chromium(III) and copper(II) with heterocyclic dithiocarbamate ligands is reported. The newly prepared compounds are characterized on the basis of near- i.r . and far- i.r . spectroscopy, electronic and e.p.r . spectra, conductivity measurements and magnetic moment studies at different temperatures. The dithio ligands exhibit bidentate behaviour acting as S,S′-donors in all the complexes. The chromium(III) compounds have g values in the 1.991-1.999 range and nephelauxetic parameters indicative of an appreciable metal- ligand covalency. The e.p.r . data of the copper(II) derivatives provide parameters typical of sulfur coordination in planar CuS4 chromophores ; the α bonding parameters are indicative of strongly covalent metal- ligand interactions.