title: Efficient water oxidation catalyzed by mononuclear ruthenium(II) complexes incorporating Schiff base ligands.
abstract: Four new charge-neutral ruthenium(II) complexes containing dianionic Schiff base and isoquinoline or 4-picoline ligands were synthesized and characterized by NMR and ESI-MS spectroscopies, elemental analysis, and X-ray diffraction. The complexes exhibited excellent chemical water oxidation activity and high stability under acidic conditions (pH 1.0) using (NH4)2Ce(NO3)6 as a sacrificial electron acceptor. The high catalytic activities of these complexes for water oxidation were sustained for more than 10 h at low concentrations. High turnover numbers of up to 3200 were achieved. A water nucleophilic attack mechanism was proposed. A Ru(V)=O intermediate was detected during the catalytic cycle by high-resolution mass spectrometry.
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, Chinese Academy of Sciences, Beijing 100190 (P. R. China), Fax: (+86) 10-6255-4670.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.forename: Fu-Min
authors.initials: FM
authors.lastname: Li
authors.forename: Wei-Liang
authors.initials: WL
authors.lastname: Zhao
authors.forename: Chuan-Jun
authors.initials: CJ
authors.lastname: Wang
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Lv
authors.forename: Quan-Qing
authors.initials: QQ
authors.lastname: Xu
authors.forename: Wen-Fu
authors.initials: WF
authors.lastname: Fu
keywords: Schiff bases; homogeneous catalysis; ruthenium; water oxidation; water splitting