Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2011-08-16

Journal: CHEMISTRY-A EUROPEAN JOURNAL

Included Journals: EI、SCIE

Volume: 17

Issue: 34

Page Number: 9520-9528

ISSN: 0947-6539

Key Words: homogeneous catalysis; isotopic labeling; neutral ligands; ruthenium; water oxidation

Abstract: Two dinuclear and one mononuclear ruthenium complexes containing neutral polypyridyl ligands have been synthesised as pre-water oxidation catalysts and characterised by (1)H and (13)C NMR spectroscopy and ESI-MS. Their catalytic water oxidation properties in the presence of [Ce(NH(4))(2)(NO(3))(6)] (Ce(IV)) as oxidant at pH 1.0 have been investigated. At low concentrations of Ce(IV) (5 mm), high turnover numbers of up to 4500 have been achieved. An (18)O-labelling experiment established that both O atoms in the evolved O(2) originate from water. Combined electrochemical study and electrospray ionisation mass spectrometric analysis suggest that ligand exchange between coordinated 4-picoline and free water produces Ru aquo species as the real water oxidation catalysts.