SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES OF Cu (II) AND Ni (II) COMPLEXES OF SCHIFF BASE DERIVED FROM INDOLE-3-CARBOXALDEHYDE AND 2-AMINO-3-BROMO-5NITRO PYRIDENE

Abstract

The Ligand, (E)-N-((1H-Indole-2-yl) methylene)-3-bromo -6-nitropyridine-2- amine, C14H9N4O2 has been synthesized from indole-3-carboxaldehyde and 2-amino-3-bromo-5-nitropyridine by condensation reaction and the resulting ligand was utilized in the Preparation of Ni(II) and Cu(II) complexes from their corresponding metal salts in ethanolic medium. All the prepared complexes as well as the ligand were identified and confirmed by elemental analyses (C, H and N), molar conductance measurements, chloride test, FT-IR, 1H NMR, Uv-Vis and Atomic Absorption Spectroscopic studies.The FTIR analysis spectra revealed that the ligand acts as a bidentate ligand coordinating through the nitrogen of the azomethine group and nitrogen of the pyridine ring. Analytical data of the complexes shows M: L ratio of 1:2. The conductivity values of 135.8 and 118.14 Scm2mol-1 for [Ni L2 (H2O) 2] Cl2 and [CuL2 (H2O)] Cl2 in DMSO at 25 0C respectively, confirms the electrolytic nature of the complexes. The synthesized ligand and its metal complexes were screened for their antimicrobial activities against two bacterial strains (Staphylococcus aureus and Escherichia coli,) and two fungal strains (Aspergillus Niger and Fusarium oxisporium) using a disc diffusion method. The tests showed that the complexes have higher antimicrobial activity than the free Schiff’s base.