Synthesis and Biological Studies of Schiff Base Metal(II) Complexes Derived from Isatin

Abstract

Potentially bioactive Schiff base metal complex is a kind of attractive reagents due to specific activities of pharmacology and physiology. Medical inorganic chemistry has exploited metal ions' unique properties to design new drugs. In this study a novel Cu(II), Ni(II), Mn(II) and Co(II) Schiff base complexes have been from p - nitroaniline, isatin and 2, 2′ bipyridyl. The elemental analyses of the complexes are confined to the stoichiometry of the type L1L2M [M = Cu(II), Ni(II), Mn(II) and Co(II)], respectively, where L is Schiff base ligand in the ratio of 1:1:1. Structures have been proposed from elemental analyses, IR, UV, 1H NMR, ESR spectral data and magnetic studies. The measured low molar conductance values in DMF indicate that the complexes are nonelectrolytes. The IR data tells us the association of C=N nitrogen atom in co - ordination to the metal ion. The UV spectral studies and magnetic measurements suggested the octahedral geometry around metal ion under investigation. The EPR spectral data shows additional proof for the octahedral geometry. In addition, the antioxidative activity was also determined. The ligand's antioxidative activity and its complexes demonstrate that, compared to the ligand, the complexes exhibit higher scavenging activity. The antibacterial activity of these compounds was studied in vitro by the disc diffusion assay against two Gram-positive bacteria like Staphylococcus aureus, Bacillus subtilis and two Gram-negative bacteria like Escherichia coli and Klebsilla pneumonia. The complexes show significant growth inhibitory activity than ligands.