New copper and ruthenium mononuclear complexes of the type [ML2(H2O)X] [X = H2O for M = Cu(II) and X = Cl for M = Ru(III)] have been prepared from 1-p-diphenylmethane-2-hydroxyimino-2-(4-chloroanilino)-1-ethanone (HL1) and 1-p-diphenylmethane-2-hydroxyimino-2-(4-toluidino)-1-ethanone (HL2). The complexes were characterized by elemental analyses, magnetic susceptibility, molar conductance, 1R, thermal analysis, and cyclic voltammetry. Stoichiometric and spectral results of the metal complexes indicated that the metal: ligand ratios in the complexes were found to be 1:2 and the ligands behave as a bidentate ligand forming neutral metal chelates through the carbonyl and oxime oxygen. The electrochemical behavior of the ligands and their complexes were obtained by cyclic voltammetry. The interaction between these complexes with DNA has also been investigated by agarose gel electrophoresis. The copper(II) complexes (3 and 4) with H2O2 as a co-oxidant exhibited strongest cleaving activity. Moreover, catalytic activities of the complexes for the disproportionation of hydrogen peroxide were also investigated in the presence of imidazole.