Oxidative Cleavage of DNA by Ruthenium(II) Complexes Containing a Ferrocene/Non-Ferrocene Conjugated Imidazole Phenol Ligand

Three mixed-ligand ruthenium­(II) complexes with general formula [Ru­(bpy)2L]­(PF6) (1–3), where L = 2-{4,5-bis­[(E)-2-ferrocenylvinyl]-1H-imidazol-2-yl}­phenol (1), 2-{4,5-bis­[(E)-2-ferrocenylvinyl]-1H-imidazol-2-yl)-4,6-dichlorophenol (2), 2-{4,5-bis­[(E)-2-(4-chlorophenyl)­ethenyl]-1H-imidazol-2-yl}­phenol (3), have been synthesized and characterized. All the three complexes bring about DNA cleavage in the presence of H2O2. Due to the presence of three redox-active metal centers in complexes 1 and 2 these two complexes show enhanced DNA cleaving activity in comparison to that exhibited by complex 3, which contains only one redox-active metal center.