title: Anion-directed self-assembly of two half-sandwich ruthenium-based metallamacrocycles as catalysts for water oxidation.
abstract: The binuclear [η(6) -(cymene)Ru(L)]2 (OTf)2 (TfO(-) =trifluoromethanesulfonate) and tetranuclear [η(6) -(cymene)Ru(L)]4 (NO3 )4 metallacycles were prepared by treating the pyridyl-substituted 8-hydroxyquinoline ligand (E)-2-[2-(pyridin-3-yl)vinyl]quinolin-8-ol (HL) with [(p-cymene)Ru(μ-Cl)Cl]2 in the presence of AgOTf or AgNO3 . The molecular structures of these complexes were confirmed by single-crystal X-ray diffraction, which revealed that both complexes have macrocycle frameworks induced by the TfO(-) and NO3 (-) counteranions, respectively. The electrochemical properties of the two metallacycles were investigated by cyclic voltammetry, which showed that they have great potential as catalysts for water oxidation. Good efficiency was obtained by utilizing the nitrate complex as a water oxidation catalyst in the presence of a Ce(IV) salt as an oxidant at high pH values.
authors.affiliation: Analysis and Testing Central Facility, School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002 (P.R. China), Fax: (+86) 555-2471263. yuweibin@ahut.edu.cn.
authors.forename: Wei-Bin
authors.initials: WB
authors.lastname: Yu
authors.forename: Qing-Ya
authors.initials: QY
authors.lastname: He
authors.forename: Hua-Tian
authors.initials: HT
authors.lastname: Shi
authors.forename: Guozan
authors.initials: G
authors.lastname: Yuan
authors.forename: Xianwen
authors.initials: X
authors.lastname: Wei
keywords: half-sandwich complexes; macrocycles; metallacycles; ruthenium; water oxidation