ASYMMETRIC BIS(BIDENTATE) AZINE LIGAND AND TRANSITION METAL COMPLEXES: SYNTHESIS, CHARACTERIZATION, DNA-BINDING AND CLEAVAGE STUDIES AND EXTRACTION PROPERTIES FOR SELECTED METALS AND DICHROMATE ANIONS

Abstract

New bis(bidentate) azine NNN’N’ donor ligand was prepared by linking (1Z,1’Z)-1,1’-{propane-1,3-diylbis[oxybenzene-4,1-diyl(1Z)eth-1-yl-1-ylidene]} dihydra-zine to pyridine-2-carbaldehyde. Two kinds of copper(II) and nickel(II) complexes with different stoichiometries were prepared. Reaction of bis(azine) ligand with Cu(II) and Ni(II) chloride with 1:1 molar ratio gave azine complexes with stoichiometry [M(L)Cl 2 ] while 2:1 molar ratio reaction of Cu(II) and Ni(II) chloride with bis(azine) composed binuclear copper complexes with general stoichiometry [M 2 (L)Cl 4 ]. The structures of both bis-azine ligand and its complexes were identified by elemental analysis, infrared spectra, UV–Vis electronic absorption spectra and magnetic susceptibility measurements, TGA and powder XRD. DNA binding and DNA cleavage activities of the synthesized metal complexes were examined by using UV-vis titration and agarose gel electrophoresis, respectively. The results indicate that all the complexes bind significantly calf thymus DNA and cleavage pBR322 DNA. Furthermore, the complexing properties of the bis-azine ligand toward selected transition metal cations and dichromate anions were also reported.