Synthesis, spectral, DFT calculation, sensor, antimicrobial and DNA binding studies of Co(II), Cu(II) and Zn(II) metal complexes with 2-amino benzimidazole Schiff base

Abstract

In this article, synthesis of Co(II), Cu(II) and Zn(II) complexes of bidentate Schiff base ligand (L) 2-((1H-Benzo [d]imidazole-4ylimmino) methyl phenol is presented here. The Schiff base and its metal (II) complexes were characterized by micro analysis and spectral techniques such as AAS, UV–Vis, FT-IR, NMR, molar conductance and magnetic moment measurements. Molar conductance reveals the non electrolytic nature of the complexes. From the analytical and spectral analysis, octahedral geometry was proposed to the synthesized metal (II) complexes. DFT calculations were done for Schiff base and metal (II) complexes to confirm the geometry of the complexes. The sensor activity of Schiff base towards calcium and magnesium ions was studied by absorption spectroscopy. Electrochemical nature of the copper (II) complex was studied by cyclic voltammetry technique and indicates the reversible nature of Cu(II)/Cu(I) couple. The antimicrobial activity of the Schiff base and its metal (II) complexes showed good potency against various microorganism such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. DNA binding properties of the metal complexes were investigated using UV–Vis absorption spectroscopy and found that the Cu (II) complex has more binding ability than L, Co(II) and Zn(II) complexes.