title: A new Ru complex capable of catalytically oxidizing water to molecular dioxygen.
abstract: We have prepared three new dinuclear ruthenium complexes having the formulas [Ru2II(bpp)(trpy)2(mu-L)]2+ (L = Cl, 1; L = AcO, 2) and [Ru2II(bpp)(trpy)2(H2O)2]3+ (3). The three complexes have been characterized through the usual spectroscopic and electrochemical techniques and, in the cases of 1 and 2, the X-ray crystal structures have been solved. In aqueous acidic solution, the acetato bridge of 2 is replaced by aqua ligands, generating the bis(aqua) complex 3 which, upon oxidation to its RuIVRuIV state, has been shown to catalytically oxidize water to molecular oxygen. The measured pseudo-first-order rate constant for the O2-evolving process is 1.4 x 10-2 s-1, more than 3 times larger than the higher one previously reported for Ru-O-Ru type catalysts. This new water-splitting catalyst also has improved stability with regard to any previously described, achieving a total of 18.6 metal cycles.
authors.affiliation: Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Sens
authors.forename: Isabel
authors.initials: I
authors.lastname: Romero
authors.forename: Montserrat
authors.initials: M
authors.lastname: Rodríguez
authors.forename: Antoni
authors.initials: A
authors.lastname: Llobet
authors.forename: Teodor
authors.initials: T
authors.lastname: Parella
authors.forename: Jordi
authors.initials: J
authors.lastname: Benet-Buchholz