Abstract

COPPER (II) COMPLEXES OF SCHIFF BASE TRIDENTATE LIGANDS: SYNTHESIS AND THEIR ANTI-MICROBIAL ACTIVITIES

K. Jayanthi and D. Satheesh*

Abstract

Two new Schiff base tridentate ligands (E)-2-(3-hydroxy-4- methoxybenzalidene)-N4-methylhydrazinecarbothioamide (L4) and (E)-2-(3,4-dihydroxybenzalidene)-hydrazinecarboamide (L5) derived from simple condensation of 3-hydroxy-4-methoxybenzaldehyde and 3,4-dihydroxybenzaldehyde with N4-methylthiosemicarbazide and semicarbazide hydrochloride respectively. Schiff base Copper (II) complexes (4a-b, 5a-b) derived from Schiff base bidentate ligand L4 and L5 with CuCl2.2H2O (4a and 5a) and CuBr2 (4b and 5b) respectively. The synthesized Schiff bases have been characterized by microanalysis, FT-IR, 1H NMR and 13C NMR. The copper (II) complexes have been characterized by microanalysis and FT-IR. All Schiff bases and copper (II) complexes showed good activity against the Gram- positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Escherichia coli and Salmonella paratyphi) and fungi (Aspergillus niger and Candida albicans). The antimicrobial results also indicate that the copper (II) complexes are better antimicrobial agents as compared to the Schiff bases.

Keywords: Schiff base, Copper complex, Anti-bacterial activity, Anti-fungal activity.