title: Efficient Light-Driven Oxidation of Alcohols Using an Organic Chromophore-Catalyst Assembly Anchored to TiO2.
abstract: The ligand 5-PO3H2-2,2':5',2″-terthiophene-5-trpy, T3 (trpy = 2,2':6',2″-terpyridine), was prepared and studied in aqueous solutions along with its metal complex assembly [Ru(T3)(bpy)(OH2)](2+) (T3-Ru-OH2, bpy = 2,2'-bipyridine). T3 contains a phosphonic acid group for anchoring to a TiO2 photoanode under aqueous conditions, a terthiophene fragment for light absorption and electron injection into TiO2, and a terminal trpy ligand for the construction of assemblies comprising a molecular oxidation catalyst. At a TiO2 photoanode, T3 displays efficient injection at pH 4.35 as evidenced by the high photocurrents (∼350 uA/cm(2)) arising from hydroquinone oxidation. Addition of [Ru(bpy)(OTf)][OTf]2 (bpy = 2,2'-bipyridine, OTf(-) = triflate) to T3 at the free trpy ligand forms the molecular assembly, T3-Ru-OH2, with the oxidative catalyst fragment: [Ru(trpy)(bpy)(OH2)](2+). The new assembly, T3-Ru-OH2, was used to perform efficient light-driven oxidation of phenol (230 μA/cm(2)) and benzyl alcohol (25 μA/cm(2)) in a dye-sensitized photoelectrosynthesis cell.
authors.affiliation: School of Chemistry & Biochemistry, School of Materials Science & Engineering, Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Toan V
authors.initials: TV
authors.lastname: Pho
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.
authors.forename: Matthew V
authors.initials: MV
authors.lastname: Sheridan
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.
authors.forename: Zachary A
authors.initials: ZA
authors.lastname: Morseth
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Sherman
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Meyer
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.
authors.forename: John M
authors.initials: JM
authors.lastname: Papanikolas
authors.affiliation: Department of Chemistry, Center for Macromolecular Science and Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Kirk S
authors.initials: KS
authors.lastname: Schanze
authors.affiliation: School of Chemistry & Biochemistry, School of Materials Science & Engineering, Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: John R
authors.initials: JR
authors.lastname: Reynolds
keywords: C−H activation; dye-sensitized photoelectrosynthesis cell; dye-sensitized solar cell; organic alcohol oxidation; solar fuels