MONONUCLEAR COPPER(II) OXAMIDO COMPLEX AS A CHELATING AGENT FOR SOME TRANSITION AND ACTINIDE METAL-IONS

Homo- or hetero-dinuclear and polynuclear metal complexes were obtaine d starting with the mononuclear Cu(II) oxamido complex as a chelating agent. The reactions of the start complex with either Cu2+ or Ni2+ cat ions yield the corresponding homo- and hetero-dinuclear complexes. The reactions with other metal cations, e.g. Co2+, Mn2+, UO(2)2+ and Fe3 yield mixed polynuclear complexes. A change of the conformation of th e oxamido group accompanies the coordination of these metal cations. T hus, the Cu(II) cation initially coordinated to N3O sites in the start complex shifts to N2O2 sites in the products. The hetero-dinuclear co mplex contains two different metal cations in equivalent coordination sites of the same ligand molecule. The complexes are characterized by elemental analysis, IR, UV-visible and mass spectra, magnetic measurem ents and their structures are thus presented. Antiferromagnetic intera ctions between adjacent transition metal cations are observed in all c omplexes. It is attributed to intramolecular magnetic exchange interac tions either through oxygen or chlorine bridges in polynuclear complex es or via the oxamido group in the dinuclear ones.