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

Complexes of Cu(II), Ni(II), Co(II) with the 9-anthraldehyde iso- nicotinoyl hydrazone ligand (HL 1 ) and the 3,5-di-tert-butyl-4-hydroxybenz- aldehyde isonicotinoyl hydrazone ligand (H2L 2 ) were synthesized by the tem- plate 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 1 H-NMR spectroscopy. From the elemental analysis, 1:2 (metal:ligand) stoichiometry for the complexes of Cu(II), Ni(II) with the ligands HL 1 and H2L 2 and 1:1 (metal:ligand) stoichio- metry for the complex of Co(II) with the ligand HL 1 are proposed. The molar conductance data showed that the complexes are non-electrolytes. The mag- netic susceptibility results coupled with the electronic and ESR spectra sugges- ted a distorted octahedral geometry for the complexes Ni(II)/HL 1 , Ni(II)/H2L 2 and Cu(II)/H2L 2 , a tetrahedral stereochemistry for the complex Cu/HL 1 and a square-planar geometry for the complex Co/HL 1 . The IR spectra demonstrated the bidentate coordination of the ligands HL 1 and H2L 2 by the O=C amide oxygen and the azomethine nitrogen, as well as monodentate coordination of the ligand HL 1 by the azomethine nitrogen in the Cu(II)complex. The anti- bacterial activity of the ligands and their metallic complexes were tested against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae.