Syntheses, characterization and antioxidant activity studies of mixed-ligand copper(II) complexes of 2,2′-bipyridine and glycine: The X-ray crystal structure of [Cu(BPy)(Gly)]ClO4

Abstract

A series of mixed-ligand complexes, viz., [CuLL'X]Y {L = bipyridine; L' = glycine; X = 0, Y = ClO4− (1); X = Cl, Y = 2H2O (2); X = H2O, Y = NO3− (3); X = CH3COO−, Y = H2O (4)} and {[Cu(Gly)(BPy)]2-μ-(SO4)}(5)} have been synthesized and characterized by means of elemental analysis, spectroscopic (FT–IR, UV–Vis and ESR), and thermal analysis, as well as magnetic moment measurements. Spectral and X-ray structural features led to the conclusion that complexes 2–5 have square-pyramidal environments around copper(II) center with coordination chromophores CuN3OCl and CuN3O2, respectively. Whereas complex 1 displays square planar geometry. The quasi-reversible CuII/CuI redox couple slightly improves its reversibility with considerable decrease in current intensity. Additionally, the antioxidant (superoxide dismutase and catalase) biomimetic catalytic activities of the obtained complexes have been tested and found to be promising candidates as dual functional mimic enzyme to serve for complete reactive oxygen species (ROS) detoxification, both with respect to the superoxide radicals and the related peroxides.