Synthesis and Characterization of Schiff Base Complexes of Cu(II), Co(II) and Cd(II) Derived from Ethylenediamine and Benzaldehyde Derivatives

Metal complexes of Cu(II), Co(II) and Cd(II) have been synthesized using two new Schiff base ligands, N,N'-bis(4-chlorobenzylidene)ethane-1,2-diamine (L1) and N,N'-bis(3-nitrobenzylidene) ethane-1,2-diamine (L2). The Schiff bases were prepared from the condensation reaction of ethylenediamine with benzaldehyde derivatives (4-chlorobenzaldehyde and 3-nitrobenzaldehyde). The complexes have been characterized by elemental analysis, conductivity measurements, UV-visible, FT-IR and magnetic susceptibility measurements. The magnetic susceptibility measurements and UV-visible spectral data revealed that the geometry of Cu(II) and Co(II) complexes are square planar, whereas the geometry of Cd(II) complex is tetrahedral. The molar conductance data showed that the complexes are non-electrolytic in nature. The complexes were screened for antibacterial activities against four human pathogenic bacteria viz. Escherichia coli, Shigella boydii, Bacillus cereus and Staphylococcus aureus. The results indicate that Cd(II) complex of ligand (L1) has higher antibacterial activity compared to the free ligands, but less than the standard drug, kanamycine. This suggests that the metal ion plays an important role in the antibacterial activities of complexes.