title: A structurally diverse Ru(II),Pt(II) tetrametallic motif for photoinitiated electron collection and photocatalytic hydrogen production.
abstract: Coupling a reactive metal to light absorbers affords molecular devices for photoinitiated electron collection and photocatalytic conversion of substrates to fuels. A new Ru(II),Pt(II) tetrametallic supramolecule, [{(phen)(2)Ru(dpp)}(2)Ru(dpq)PtCl(2)](PF(6))(6), and the trimetallic precursors, [{(phen)(2)Ru(dpp)}(2)RuCl(2)](PF(6))(4) and [{(phen)(2)Ru(dpp)}(2)Ru(dpq)](PF(6))(6), have been synthesized, and their redox, spectroscopic, spectroelectrochemical, photophysical and photocatalytic properties studied. They efficiently absorb UV and visible light. The electrochemistry of [{(phen)(2)Ru(dpp)}(2)Ru(dpq)PtCl(2)](PF(6))(6) suggests a lowest-lying terminal Ru→dpq charge-separated state that quenches the emission of the parent complex with non-unity population of the emissive (3)MLCT excited state. Photolysis of [{(phen)(2)Ru(dpp)}(2)Ru(dpq)PtCl(2)](6+) at 470 nm with DMA gives multielectron reduction, storing electrons in a new manner on the central (dpp)(2)Ru(II)(dpq) moiety. Addition of H(2)O to the photolysis system produces 21 μmol of H(2) in 5 h, with 115 turnovers of the tetrametallic photocatalyst.
authors.affiliation: Department of Chemistry, Virginia Polytechnic Institute and State University, 107 Davidson Hall, Blacksburg, VA 24061-0212, USA.
authors.forename: Jessica D
authors.initials: JD
authors.lastname: Knoll
authors.forename: Shamindri M
authors.initials: SM
authors.lastname: Arachchige
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Brewer
mesh_terms: D002384:Catalysis; D002413:Cations, Divalent; D004563:Electrochemistry; D004583:Electrons; D006859:Hydrogen / Q000737:chemistry*; D008024:Ligands; D008027:Light; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010777:Photochemistry / Q000379:methods*; D011005:Plutonium / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D013057:Spectrum Analysis; D014867:Water / Q000737:chemistry*
chemical_list: D002413:Cations, Divalent; D008024:Ligands; D009942:Organometallic Compounds; D014867:Water; D011005:Plutonium; D012428:Ruthenium; D006859:Hydrogen