Syntheses,structures and catalase-like activities of mono-,tri- and pentanuclear Cu(II),Cu(II)-Co(II) complexes with cyanide and ONO tridentate oxime ligand

A novel cyanide containing mononuclear copper(II) oxime complex K[CuL(CN)] (1) was synthesized as a starting material to make new polynuclear complexes. Trinuclear complexes K₂[{CuL(NC)}₂(ML)] (M = Co(II) (2), Cu(II) (3) and pentanuclear complexes K₂[{CuL(NC)}₄M] (M = Co(II) (4), Cu(II) (5)) of 4-(2-amino-4-methylphenolisonitrosoacetyl)biphenyl (H₂L) have been synthesized and characterized by elemental analysis, molar conductance, FT-IR, magnetic data. The lowest energy model structures of the ligand and its mononuclear Cu(II) complex have been determined by MOPAC 2007 program using PM6 method. Catalytic activities of the complexes for the disproportionation of hydrogen peroxide were investigated in the presence of imidazole. The multinuclear Cu(II)-Co(II) complexes (2, 4) display efficiency in disproportion reactions of hydrogen peroxide producing water and dioxygen in catalase-like activity.