Synthesis, spectroscopic and electrochemichal characterization of mixed cobalt complexes with aminoacids and isonitrosoacetophenone. Biological activities

Abstract

Complexes formed from isonitrosoacetophenone and aminoacids such as L-Phenylalanine, L-Tryptophan and L-Histidine having the formula [Co(INAP)L(H2O)2] have been synthesized.The complexes have been characterized using elemental analyses, molar conductance, UV-Vis, IR and 1H NMR spectroscopy. The value of molar conductance indicates them to be non-electrolytes.The IR spectra support the binding of the ligands with two N and two O donor sites to the cobalt(II) ion giving an arrangement of N2O2 donor group.Electrochemical behavior of the complexes have been investigated by cyclic voltammetry which shows that the chelate structure and electron donating effects of the ligand substituent are among the factors influencing the redox potentials of the complexes.The antimicrobial activities of the complexes were evaluated against several pathogenic microorganisms to assess their antimicrobial potentials. The cobalt complexes were found to be more active against Gram-positive than Gram-negative bacteria.Furthermore, the antioxidant efficiencies of the metal complexes were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavening activity. The antioxidant activity of the complexes indicates their high scavenging activity against the radical DPPH.