Water oxidation catalyzed by mononuclear ruthenium complexes with a 2,2′-bipyridine-6,6′-dicarboxylate (bda) ligand: How ligand environment influences the catalytic behavior
2014 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 53, no 3, 1307-1319 p.Article in journal (Refereed) Published
A new water oxidation catalyst [RuIII(bda)(mmi)(OH 2)](CF3SO3) (2, H2bda = 2,2′-bipyridine-6,6′-dicarboxylic acid; mmi = 1,3- dimethylimidazolium-2-ylidene) containing an axial N-heterocyclic carbene ligand and one aqua ligand was synthesized and fully characterized. The kinetics of catalytic water oxidation by 2 were measured using stopped-flow technique, and key intermediates in the catalytic cycle were probed by density functional theory calculations. While analogous Ru-bda water oxidation catalysts [Ru(bda)L2] (L = pyridyl ligands) are supposed to catalyze water oxidation through a bimolecular coupling pathway, our study points out that 2, surprisingly, undergoes a single-site water nucleophilic attack (acid-base) pathway. The diversion of catalytic mechanisms is mainly ascribed to the different ligand environments, from nonaqua ligands to an aqua ligand. Findings in this work provide some critical proof for our previous hypothesis about how alternation of ancillary ligands of water oxidation catalysts influences their catalytic efficiency.
Place, publisher, year, edition, pages
2014. Vol. 53, no 3, 1307-1319 p.
Transition-Metal-Complexes, N-Heterocyclic Carbene, Dimer Complex, Energy, Efficient, Density, Site, Thermochemistry, Challenges, Solvation
IdentifiersURN: urn:nbn:se:kth:diva-142811DOI: 10.1021/ic401701zISI: 000330812700011ScopusID: 2-s2.0-84893233983OAI: oai:DiVA.org:kth-142811DiVA: diva2:704550
FunderSwedish Energy AgencyKnut and Alice Wallenberg Foundation
QC 201403122014-03-122014-03-122014-11-10Bibliographically approved