Synthesis and characterization of homotrimetallic copper complexes derived from bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone.

Copper (II) complexes [Cu(3)(nph)(μ(2)-X)(2)(H(2)O)(6)]·2H(2)O [X=Cl (1), (ClO(4)) (3)] and [Cu(3)(nph)(NO(3))(2)(H(2)O)(6)] (2) have been synthesized from bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone in methanol medium and characterized. The structures of the complexes have been discussed in the light of data obtained from analytical, thermoanalytical, mass spectral studies, molar conductance, magnetic moment, electronic, EPR, IR, FT-IR spectroscopic studies. The molar conductance values for the complexes fall in the region 0.5-0.9 Sm(2) mol(-1) in DMSO solution indicating that all of them are non-electrolyte. The magnetic moment values for the complexes suggest weak M-M interaction in the structural unit of the complexes. The dihydrazone ligand is present in enol form in all of the complexes. Copper centre has tetragonally distorted octahedral stereochemistry in chlorido and perchlorato complexes while in nitrato complex, copper has mixed square-pyramidal and distorted-octahedral stereochemistry. The EPR parameters of the complexes indicate that the copper centre has the doublet state as the ground state.