COPPER(II) AND NICKEL(II) COMPLEXES OF 2,3-BUTANEDIONE BIS(N(3)-SUBSTITUTED THIOSEMICARBAZONES)

Copper(II) and nickel(II) complexes of 2,3-butanedione bis(N(3)-methyl -, bis(N(3)-dimethyl-, bis(pyridyl- and bis(hexamethyleneiminylthiosem icarbazone), (H(2)Bu3M, H(2)Bu3DM, H(2)Bupip and H(2)Buhexim, respecti vely) have been prepared and studied spectroscopically. The four thios emicarbazones have been characterized by their melting points, as well as IR, electronic and NMR (H-1, C-13) spectra. The four coordinate co pper(II) complexes have been studied by EPR spectroscopy and the coppe r(II) and nickel(II) complexes by a number of the spectroscopic techni ques mentioned above. Upon formation of these complexes, loss of the N (2)H hydrogens occurs and the ligands coordinate to the metal centers as dianionic, tetradentate N2S2 ligands. The crystal structures of H(2 )Bupip and the nickel(II) complex of 2,3-butanedione N3-methylphenylth iosemicarbazone, [Ni(Bu3MPh)], have been solved. (C) 1997 Elsevier Sci ence Ltd.