Synthesis, characterization and superoxide dismutase activity of some four coordinated copper(II) complexes

Mixed ligand copper(II) complexes, viz., [Cu(Br-SAA)(ImH)], [Cu(Br-SAA)(MeImH)], [Cu(Br-SAA)(EtImH)], [Cu(Br-SAA)(BenzImH)] and [Cu(Br-SAA)(MebenzImH)], where Br-SAA = 5-bromosalicylideneanthranilic acid, ImH = imidazole, MeImH = 2-methyl imidazole, EtImH = 2-ethyl imidazole, BenzImH = benzimidazole, MebenzImH = 2-methyl benzimidazole are synthesized and characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, FAB mass, IR, electronic, EPR spectral and cyclic voltammetric studies. The complex [Cu(Br-SAA)(ImH)] structurally characterized by single crystal X-ray crystallography, crystallizes in the triclinic space group P-1 with unit cell parameters: a = 3.7875(15)Å, b = 10.6246(19)Å, c = 19.977(3)Å, α = 96.565(14)°, β = 94.45(2)°, γ = 92.32 (2)° and Z = 2. The one electron paramagnetic complexes show a d-d band near 700 nm in DMSO and a cyclic voltammetric response due to Cu(II)/Cu(I) couple. The complexes show the presence of a distorted square planar CuN2O2 coordination geometry. Superoxide dismutase activity of these complexes have also been examined.