Synthesis, characterization and antibacterial activity of Schiff base of Cu (II), Ni (II) and Co (II) complexes

Due to their importance as catalysts in many reactions and their biological activities, an interest in the synthesis and characterization of transition metal complexes containing Schiff bases is increasing. The major aim of this study was to compare the antibacterial activity of the ligands with their metal complexes. We have successfully synthesized Cu (II), Ni (II) and Co (II) complexes of N, N-Bis(vanillinidene )-1,2-phenylenediamine and N,N-Bis(salicylidene)-1,2-phenylenediamine. The Schiff’s bases were synthesized by the reaction of o-phenylenediamine with salisaldehyde or o-vanillin and their metal complex were synthesized by the reaction of the ligands with the metal salts. The structure of all the synthesized ligands were confirmed using NMR, IR and UV-Vis spectral analysis and their metal complexes were confirmed using IR and UV-vis spectra. The synthesized ligands and their metal complexes were screened for their antibacterial activities against Escherichia coli, Staphylococcus aureus, and Klebsiella pneumonia bacterial strains by using disc diffusion method. Among the synthesized compounds, the ligand L1 is moderately active against Staphylococcus aureus, K. pneumonia and Escherichia coli bacteria strain, CoL1 exhibited the highest activity, with 22mm zone of inhibition against staphylococcus aureus, compared to standard gentamycin activity, with 21 mm zone of inhibition.