title: Light-driven electron transfer between a photosensitizer and a proton-reducing catalyst co-adsorbed to NiO.
abstract: While intermolecular hole-hopping along the surface of semiconductors is known, there are no previous examples of electron-hopping between molecules on a surface. Herein, we present the first evidence of electron transfer from the photoreduced sensitizer Coumarin-343 (C343) to complex 1, both bound on the surface of NiO. In solution, 1 has been shown to be a mononuclear Fe-based proton-reducing catalyst. The reduction of 1 is reversible and occurs within 50 ns after excitation of C343. Interfacial recombination between the reduced 1((-)) and NiO hole occurs on a 100 μs time scale by non-exponential kinetics. The observed process is the first essential step in the photosensitized generation of H(2) from a molecular catalyst in the absence of a sacrificial donor reagent.
authors.affiliation: Ångström Laboratory, Department of Chemistry, Uppsala University, Box 523, 75120 Uppsala, Sweden.
authors.forename: James M
authors.initials: JM
authors.lastname: Gardner
authors.forename: Maryline
authors.initials: M
authors.lastname: Beyler
authors.forename: Michael
authors.initials: M
authors.lastname: Karnahl
authors.forename: Stefanie
authors.initials: S
authors.lastname: Tschierlei
authors.forename: Sascha
authors.initials: S
authors.lastname: Ott
authors.forename: Leif
authors.initials: L
authors.lastname: Hammarström
mesh_terms: D000327:Adsorption; D002384:Catalysis; D003374:Coumarins / Q000737:chemistry*; D004579:Electron Transport; D008027:Light; D008968:Molecular Conformation; D009569:Nitric Oxide / Q000737:chemistry*; D010084:Oxidation-Reduction; D017319:Photosensitizing Agents / Q000737:chemistry*; D011522:Protons; D013237:Stereoisomerism; D013499:Surface Properties
chemical_list: D003374:Coumarins; D017319:Photosensitizing Agents; D011522:Protons; C552279:coumarin 343; D009569:Nitric Oxide