title: The use of a vanadium species as a catalyst in photoinduced water oxidation.
abstract: The first water oxidation catalyst containing only vanadium atoms as metal centers is reported. The compound is the mixed-valence [(V(IV)5V(V)1)O7(OCH3)12](-) species, 1. Photoinduced water oxidation catalyzed by 1, in the presence of Ru(bpy)3(2+) (bpy = 2,2'-bipyridine) and Na2S2O8, in acetonitrile/aqueous phosphate buffer takes place with a quantum yield of 0.20. A hole scavenging reaction between the photochemically generated Ru(bpy)3(3+) and 1 occurs with a bimolecular rate constant of 2.5 × 10(8) M(-1) s(-1). The time-resolved formation of the oxidized molecular catalyst 1(+) in bimolecular reactions is also evidenced for the first time by transient absorption spectroscopy. This result opens the way to the use of less expensive vanadium clusters as water oxidation catalysts in artificial photosynthesis schemes.
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Messina , and Centro Interuniversitario per la Conversione Chimica dell'Energia Solare (SOLAR-CHEM), sezione di Messina, 98166 Messina, Italy.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Santoni
authors.forename: Giuseppina
authors.initials: G
authors.lastname: La Ganga
authors.forename: Viviana
authors.initials: V
authors.lastname: Mollica Nardo
authors.forename: Mirco
authors.initials: M
authors.lastname: Natali
authors.forename: Fausto
authors.initials: F
authors.lastname: Puntoriero
authors.forename: Franco
authors.initials: F
authors.lastname: Scandola
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Campagna
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry; D002384:Catalysis; D008027:Light; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D014639:Vanadium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D014639:Vanadium; D014867:Water; D015082:2,2'-Dipyridyl