Copper(II), Nickel(II), Cobalt(II) and Manganese(II) Complexes of Schiff Bases: Synthesis, Characterization, and Antibacterial Properties

Schiff base ligands containing different donor atoms(like N,O,S,etc.) show a wide range of biological activities and are of special interest because of the variety of methods in which they are bonded to the transition-metal ions[1]. Schiff bases and their complexes have attracted considerable attention because of their usages in various biological fields[2], catalysis reactions[1], water photolysis[2] and etc.Similarly,pyridine base ligands have also been used in many biochemical studies designed to develop molecular systems of biological and medicinal importance.[5,6] In our research, we describe the synthesis of four new mononuclear complexes of Cu(II), Ni(II), Co(II), Mn(II) containing the corresponding N-donor schiff base ligand. The structures of the ligand and its metal complexes were studied by elemental analyses, spectroscopic methods(FTIR, UV-vis, NMR). Their electrochemical properties were studied by cyclic voltammetry technique. Also antibacterial activities of the ligand and its complexes were tested against two Gram-negative bacteria Escherichia coli(ATCC 25922) and Pseudomonas aeruginosa(ATCC 9027) and two Gram-positive bacteria Staphylococcus aureus(ATCC6538) and Corynebacterium renale. The results exhibited suitable antibacterial properties for ligand and its complexes . The study has shown that complexation of ligand to metallic center lead to enhancement of antibacterial activity