Synthesis, DNA-binding and photocleavage studies of Ru(II) complexes of phenyl-(4,5,9,14-tetraaza-benzo[b]triphenylen-1,1-yl)-methanone

A novel polypyridyl ligand phenyl-(4,5,9,14-tetraaza-benzo[b]triphenylen-1,1-yl)-methanone (PTBM) and its complexes [Ru(phen)(2)(PTBM)](2+) (1) (phen = 1,10-phenanthroline) and [Ru(bpy)(2) (PTBM)](2+) (2) (bpy = 2,2'-bipyridine) have been synthesized and characterized by elemental analysis, mass spectroscopy, and H-1 NMR. The DNA-binding properties of the two complexes were investigated by spectroscopic and viscosity measurements. The results indicate that both complexes bind to DNA via an intercalative mode and the DNA-binding affinity of complex 1 is greater than that of complex 2. When irradiated at 365 nm, complex 1 was found to be a more-effective DNA-cleaving agent than complex 2.