Synthesis, structure and superoxide dismutase activity of two self-assembly transition metal complexes containing a tridentate amino-Schiff base deviating from salicylaldehyde with glycine

Two new transition metal (Cu, Ni) complexes with amino-Schiff base ligand, (C9H7NO3)Cu(C14H12N2)·H2O (1) and (C9H7NO3)Ni(C3H4N2)3·H2O (2), have been designed and synthesized in ethanol solution at room temperature. Both of the complexes have been characterized by elemental analysis, IR spectra, UV-vis spectroscopy and X-ray single crystal diffraction. For complex 1, the coordination environment of the central copper atom is a distorted square pyramid, and one-dimensional chain is formed through the inter-molecular hydrogen bonds (O4-H2W⋯O3, O4-H2W⋯O3#1 (#1: −x+1, y, −z+3/2)) and weak interactions (π-π stacking interaction) between the phenyl rings. For complex 2, the nickel atom is 6-coordinated and in a distorted octahedral environment, and a discrete hydrogen-bond cluster (four molecules are connected by hydrogen bonds into a group) is formed via two types of intra-molecular hydrogen bonds (O-H⋯O, N-H⋯O) and inter-molecular hydrogen bonds (O-H⋯O, N-H⋯O).