Abstract

ANTIBACTERIAL, DNA CLEAVAGE AND SPECTRAL STUDIES OF Cu(II), Ni(II), Zn(II) and Mn(II) SCHIFF BASE METAL COMPLEXES DERIVED FROM 5 - CHLORO SALICYLALDEHYDE

P. Subramanian* and B. Muthulakshmi

ABSTRACT

The in-vitro antibacterial activities of the new ligand and its Cu(II), Ni(II) Zn(II) and Mn(II) complexes derived from 5-Chloro Salicylaldehyde were tested against two gram negative bacteria (Klebsiella pneumoniae and Escherichia coli) and one gram positive bacteria (Staphylococcus aureus) by well diffusion method using nutrient agar as the medium. These studies revealed that the new Schiff base complexes were found to be more active than the Schiff base ligand. The pUC18 DNA cleavage study was monitored by gel electrophoresis method. From this study, it was found that the complex cleaves pUC18 DNA in the presence of the oxidant H2O2. An economical and environmental friendly method has been developed for the synthesis of Schiff base ligand N,N'-bis(5-chlorosalicylidene) phenylmethane diamine by one pot three component reaction of 5- chlorosalicylaldehyde, benzaldehyde and ammonium acetate salt in the presence of triethyl amine under solvent free condition at room temperature. Cu(II), Ni(II) Zn(II) and Mn(II) complexes have been prepared by refluxing the Schiff base ligand and metal salts in methanol. The Ligand and it’s metal complexes have been characterized by elemental analysis, FT–IR, UV–Vis.,1H NMR, 13C-NMR, EPR and Magnetic studies. In all new complexes, the ligand is tetradentate, the oxygen in the ortho position and azomethine nitrogen atoms of the ligand coordinated to the metal ion.

Keywords: Antibacterial activity, DNA cleavage, Schiff-base ligand, metal complexes.