Photoinduced Electron Transfer Reactions of tris(4,4’-dimethoxy-2,2’-bipyridyl)ruthenium(II)cation with Quinones in Aqueous Medium

Photoinduced electron transfer reactions of [Ru(dMeObpy)3] 2+ complex with quinones have been studied in aqueous medium by luminescent quenching technique. The complex shows an absorption and emission maximum of 448 nm and 608 nm respectively in aqueous medium. It has an excited state lifetime of 232 ns. The quenching rate constant kq is sensitive to the nature of the quencher and the electron transfer distance between the luminophore and the quencher, the reduction potential of the quinones. The nature of quenching is confirmed from ground state absorption studies. The oxidative nature of quenching is confirmed from the formation of Ru 3+ ion and quinone anion radical. Structural effects also influence the rate of electron transfer reaction.