4,4'-(DIPHENYLMETHANE-4,4'-DIYLDINITRILO)DIPENTAN-2-ONE AND 4,4'-(DIPHENYLETHER-4,4'-DIYLDINITRILO)DIPENTAN-2-ONE LIGANDS AND THEIR Ni(II), Cu(II) COMPLEXES: SYNTHESIS, CHARACTERIZATION, DNA CLEAVAGE STUDIES

The synthesis of two new ligands 4,4'-(diphenylmethane-4,4'-diyldinitrilo)dipentan-2-one (H2L¹) and 4,4'-(diphenylether-4,4'-diyldinitrilo)dipentan-2-one (H2L²) is reported. The ligands have two acetylacetone subunits separated by diphenylmethane or diphenylether group. The ligands form stable dinuclear complexes with Ni(II) and Cu(II) ions. Ligands and their complexes were characterized by elemental analysis, m.p., IR, molar conductivity and magnetic moment measurements. The interaction between these compounds with DNA has also been investigated by agarose gel electrophoresis, we found that the nickel(II) and copper(II) complexes can cleave supercoiled pBR322 DNA to nicked and linear forms. The copper(II) complexes with H2O2 as a cooxidant exhibited the strongest cleaving activity. The free ligands were also characterized by ¹H NMR spectra. The IR of the free ligands and their complexes are compared and discussed. The extraction ability of the ligands have been examined by the liquid-liquid extraction of selected transition metal [Mn²+, Co²+, Ni²+, Cu²+, Zn²+, Cd²+, Hg²+ and Pb²+] cations. The ligands show strong binding ability toward mercury(II) ion.