Template synthesis, characterization and antimicrobial activity of some new complexes with isonicotinoyl hydrazone ligands

Abstract

Complexes of Cu(II), Ni(II), Co(II) with the 9-anthraldehyde isonicotinoyl hydrazone ligand (HL1) and the 3,5-di-tert-butyl-4-hydroxybenzaldehyde isonicotinoyl hydrazone ligand (H2L2) were synthesized by the template method. The complexes were characterized by analytical analysis, IR, UV-Vis and ESR spectroscopy, magnetic measurements, conductometry and thermal analysis and the two ligands by 1H-NMR spectroscopy. From the elemental analysis, 1:2 (metal:ligand) stoichiometry for the complexes of Cu(II), Ni(II) with the ligands HL1 and H2L2 and 1:1 (metal:ligand) stoichiometry for the complex of Co(II) with the ligand HL1 are proposed. The molar conductance data showed that the complexes are non-electrolytes. The magnetic susceptibility results coupled with the electronic and ESR spectra suggested a distorted octahedral geometry for the complexes Ni(II)/HL1, Ni(II)/H2L2 and Cu(II)/H2L2, a tetrahedral stereochemistry for the complex Cu/HL1 and a square-planar geometry for the complex Co/HL1. The IR spectra demonstrated the bidentate coordination of the ligands HL- and H2L2 by the O=C amide oxygen and the azomethine nitrogen, as well as monodentate coordination of the ligand HL1 by the azomethine nitrogen in the Cu(II)complex. The antibacterial activity of the ligands and their metallic complexes were tested against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae.Keywords: Cu(II), Ni(II) and Co(II) complexes; Template synthesis; Isonicotinoylhydrazone; Characterization; Antibacterial activity. © 2009 Copyright (CC) SCS.