Efficient DNA photocleavage by [Ru(bpy)2(dppn)]2+ with visible light

Abstract

The population and reactivity of two low-lying excited states in [Ru(bpy)₂(dppn)]²⁺ (bpy = 2,2′-bipyridine, dppn = benzo[i]dipyrido[3,2-a:2′,3′-c]phenazine), a weakly emissive ³MLCT state and a long-lived ligand-centered ³ππ* state, lead to efficient photoinduced DNA damage. Irradiation with visible light results in nearly complete DNA cleavage within 30 s (λ_irr ≥ 455 nm), likely from the combined action of guanineoxidation and the production of reactive oxygen species derived from ¹O₂.