Antibacterial Co(II), Ni(II), Cu(II) and Zn(II) complexes with biacetyl-derived Schiff bases

Abstract

The condensation reactions of biacetyl with orthohydroxyaniline and 2-aminobenzoic acid to form bidendate NO donor Schiff bases were studied. The prepared Schiff base ligands were further utilized for the formation of metal chelates having the general formula [ML2.2H2O] where M = Co(II), Ni(II), Cu(II) and Zn(II) and L = HL1 and HL2. These new compounds were characterized by conductance measurements, magnetic susceptibility measurements, elemental analysis, and IR, 1H-NMR and electronic spectroscopy. Both Schiff base ligands were found to have a mono-anionic bidentate nature and octahedral geometry was assigned to all metal complexes. All the complexes contained coordinated water which was lost at 141-160 ?C. These compounds were also screened for their in-vitro antibacterial activity against four bacterial species, namely; Escherichia coli, Staphylococcus aureus, Salmonella typhi and Bacillus subtillis. The metal complexes were found to have greater antibacterial activity than the uncomplexed Schiff base ligands.