Homo- and heteropolynuclear copper(II) complexes containing a new diimine-dioxime ligand and 1,10-phenanthroline: synthesis, characterization, solvent-extraction studies, catalase-like functions and DNA cleavage abilities

A series of homo-, heterodinuclear and homotrinuclear copper(II) complexes containing a new Schiff base ligand and 1,10-phenanthroline were synthesized. Based on results of elemental analyses, FTIR, H-1-and C-13-NMR spectra, conductivity measurements and magnetic susceptibility measurements, the complexes had general compositions {[Cu(L)(H2O)M(phen)(2)](ClO4)(2) [M = Cu(II), Mn(II), Co(II)]} and {[Cu-3(L)(2)(H2O)(2)](ClO4)(2)}. The metal: L : phen ratio is 2:1 : 2 for the dinuclear copper(II) complexes and the metal: L ratio was 3:2 for the trinuclear copper(II) complex. The liquid-liquid extraction of various transition metal cations [Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II), Hg(II)] from the aqueous phase to the organic phase was carried out using the diimine-dioxime ligand. It was concluded that the ligand can effectively be used in solvent extraction of copper(II) from the aqueous phase to the organic phase. Furthermore, catalytic activitiy of the complexes for the disproportionation of hydrogen peroxide was also investigated in the presence of imidazole. Dinuclear copper(II)-manganese(II) complex has some similarity to manganese catalase in structure and activity. The interaction between these complexes and DNA has also been investigated by agarose gel electrophoresis; we found that the homo-and heterodinuclear copper complexes can cleave supercoiled pBR322 DNA to nicked and linear forms in the presence of H2O2. Copyright (C) 2009 John Wiley & Sons, Ltd.