Synthesis, Spectroscopic characterization and antibacterial screening of Zn(II), Cu(II) and VO(IV) complexes derived from Indole-3-Acetic Acid

Abstract

ABSTRACT:In the present study, mononuclear metal complexes with zinc(II), copper(II) and vanadium(IV) have been synthesized by using indole-3-acetic acid (IAA) as primary ligand and 2,2'-bipyridine (bpy) and 8-hydroxy quinolone (8Hq) as secondary ligands. These synthesized complexes have been analyzed by various spectroscopic techniques like FT-IR, 1H-NMR, UV-Visible and by conductometry. The FT-IR spectroscopy revealed that nitrogen atom of ligand does not coordinate with metal ions. The vibrational frequency of NH was not shifted to a considerable extent in complexes as compared to the free ligand (IAA). As a result, the indole-3-acetic acid works as simple carboxylic acid ligands even in the synthesis of chelate complexes. The outcomes of 1HNMR show that the peak for carboxylic proton in IAA at 12.19 ppm vanishes on complexation, which suggests the replacement of the carboxylic proton by the metal moiety. The molar conductivity values of the synthesized compounds revealed the nonelectrolytic and non-conductive nature. Antibacterial screening was performed by thewell diffusion method against Gram-negative (Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria. All complexes exhibited higher antimicrobial potential than the standard reference drug, Ampicillin. It was confirmed by inhibition zones that metal complexes are efficient antibiotic agents.