Near-IR/Visible-Emitting Thiophenyl-Based Ru(II) Complexes: Efficient Photodynamic Therapy, Cellular Uptake, and DNA Binding.

Near-IR-emitting and/or efficiently photodynamic water-soluble Ru(II) complexes that hold great application potentials as photodynamic therapy and/or photodetection agents for cancers have been poorly explored. In this paper, the solvatochromism, calf thymus DNA binding, and singlet oxygen generation properties of a known ruthenium(II) complex of visible-emitting Ru(bpy)(dtdpq) () and a new homoleptic complex of near-IR-emitting Ru(dtdpq) () (bpy = 2,2'-bipyridine, dtdpq = 2,3-bis(thiophen-2-yl)pyrazino[2,3-][1,10]phenanothroline) in water are reported. Moreover, DNA photocleavage, singlet oxygen generation in HeLa cells, cellular uptake/localization, and in vitro photodynamic therapy for cancer cells of water-soluble are described in detail. The results show that acted as potent photodynamic cancer therapy and mitochondrial imaging agents. exhibited very strong solvatochromism from a visible emission maximum at 588 nm in CHCl to the near-IR region at 700 nm in water and singlet oxygen generation yield in water (23%) and DNA binding properties (intercalative DNA binding constant on the order of 10 M) comparable to those of , which should make attractive for the aforementioned applications of if the water solubility of can be improved enough for the studies above.