Synthesis, spectral characterization, electrochemical, anti-microbial, DNA binding and cleavage studies of new binuclear Schiff base metal(II) complexes derived from o-hydroxyacetophenone

Abstract A new tetradentate binucleating ligand [H 2 L] has been synthesized by condensation between 3, 3′-diaminobenzidine and o-hydroxyacetophenone in the molar ratio 1:4. The reaction of the ligand with metal chelation leads to bimolecular complexes of the general formula [M 2 (L)]. The ligand and metal complexes have been characterized by elemental analysis, UV, IR, …  1 H NMR, 13 C NMR, conductivity measurements and magnetic studies. In conductivity experiments, all metal chelates showed to be non-electrolytic in nature. The bonding sites are the nitrogen atoms of the azomethine and the oxygen atoms of the phenolic groups. The anti-microbial activities were screened against one Gram-positive bacterium ( Streptococcus pyogenes ) and one Gram-negative bacterium ( Klebsella pneumoniae ). The anti-fungal activity was screened against Asperigillus flavus . All complexes showed significant anti-bacterial and anti-fungal activities. The DNA binding studies were performed by electronic spectroscopy, cyclic voltammetry studies and viscosity measurements. The cleavage studies of these complexes are investigated by gel electrophoresis method in the presence of peroxide. All complexes cleaved efficiently and the complex interacts with DNA through an intercalating way.