title: Quantitative photochemical formation of [Ru(tpy)(bpy)H]+.
abstract: Quantitative photochemical production of [Ru(tpy)(bpy)H](+) (Ru-H(+)) was achieved by irradiation of [Ru(tpy)(bpy)(DMF)](2+) (Ru-DMF(2+); DMF = N,N-dimethylformamide) in a tetrahydrofuran (THF) solution containing excess triethylamine (NEt(3)). The mechanism of the Ru-H(+) formation was investigated in detail. A photochemical ligand substitution reaction of Ru-DMF(2+) in THF proceeded to give [Ru(tpy)(bpy)(THF)](2+) (Ru-THF(2+)) with a quantum yield of (7.6 +/- 0.7) x 10(-2). In the presence of NEt(3), a similar photochemical ligand substitution reaction also proceeded quickly, but the products were an equilibrium mixture of Ru-THF(2+) and [Ru(tpy)(bpy)(NEt(3))](2+) (Ru-NEt(3)(2+)) with a considerable amount of Ru-H(+) even in the first stage of the photochemical reaction. The equilibrium constant between Ru-THF(2+) and Ru-NEt(3)(2+) was determined as 6.9 +/- 2.1. Irradiation to Ru-NEt(3)(2+) gave Ru-H(+) with a quantum yield of (9.1 +/- 0.5) x 10(-3). An important intermediate, Ru-NEt(3)(2+), was isolated, and its properties were investigated in detail.
authors.affiliation: Department of Chemistry, Tokyo Institute of Technology, O-okayama 2-12-1, E1-9, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Matsubara
authors.forename: Hideo
authors.initials: H
authors.lastname: Konno
authors.forename: Atsuo
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Osamu
authors.initials: O
authors.lastname: Ishitani