title: Highly efficient and selective photocatalytic oxidation of sulfide by a chromophore-catalyst dyad of ruthenium-based complexes.
abstract: Electronic coupling across a bridging ligand between a chromophore and a catalyst center has an important influence on biological and synthetic photocatalytic processes. Structural and associated electronic modifications of ligands may improve the efficiency of photocatalytic transformations of organic substrates. Two ruthenium-based supramolecular assemblies based on a chromophore-catalyst dyad containing a Ru-aqua complex and its chloro form as the catalytic components were synthesized and structurally characterized, and their spectroscopic and electrochemical properties were investigated. Under visible light irradiation and in the presence of [Co(NH3)5Cl]Cl2 as a sacrificial electron acceptor, both complexes exhibited good photocatalytic activity toward oxidation of sulfide into the corresponding sulfoxide with high efficiency and >99% product selectivity in neutral aqueous solution. The Ru-aqua complex assembly was more efficient than the chloro complex. Isotopic labeling experiments using (18)O-labeled water demonstrated the oxygen atom transfer from the water to the organic substrate, likely through the formation of an active intermediate, Ru(IV)═O.
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials and HKU-CAS Joint Laboratory on New Materials, Technical Institute of Physics and Chemistry and University of Chinese Academy of Sciences, CAS , Beijing 100190, People's Republic of China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Li
authors.forename: Fu-Min
authors.initials: FM
authors.lastname: Li
authors.forename: Wei-Liang
authors.initials: WL
authors.lastname: Zhao
authors.forename: Yong-Hua
authors.initials: YH
authors.lastname: Tian
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.forename: Rong
authors.initials: R
authors.lastname: Cai
authors.forename: Wen-Fu
authors.initials: WF
authors.lastname: Fu