A computational study of the mechanism for water oxidation by (bpc)(bpy)(RuOH2)-O-II
2014 (English)In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 43, no 36, 13776-13782 p.Article in journal (Refereed) Published
A mechanistic study on the catalytic cycle water oxidation with 1 [(bpc)(bpy)(RuOH2)-O-II](+) (Hbpc = 2,2'-bipyridine-6-carboxylic acid, bpy = 2,2'-bipyridine) is described in this paper. Stepwise oxidation via proton-coupled electron transfer gives 3 [(bpc)(bpy)Ru-IV=O](+). An active 4 [(bpc)(bpy)Ru-V=O](2+), which is involved in the OO bond formation is generated from further 1e(-) oxidation of 3. Another different possible reaction at 4 was investigated and new destructive paths involving overoxidation of the metal were identified. The most viable path for OO bond formation via a water nucleophilic attack at the oxo of 4 is found to be the rate-determining step in this water oxidation catalytic cycle, and the hydro-peroxo 6 [(bpc)(bpy)-(RuOOH)-O-III](+) is generated accompanied with a proton transfer. The super-oxo 7(side-on) [(bpc)(bpy)(RuOO)-O-IV](+) and 8(side-on) [(bpc)(bpy)(RuOO)-O-V](2+), both low spin species, are generated by further oxidations of 6. Through an intersystem crossing they can transform to their high spin states, 9(end-on) [(bpc)(bpy)(RuOO)-O-IV](+) and 12(end-on) [(bpc)(bpy)(RuOO)-O-V](2+), respectively. Following a dissociative pathway O-2 is readily generated from both 9(end-on) and 12(end-on).
Place, publisher, year, edition, pages
2014. Vol. 43, no 36, 13776-13782 p.
IdentifiersURN: urn:nbn:se:kth:diva-145657DOI: 10.1039/c4dt02113dISI: 000341282100035ScopusID: 2-s2.0-84906302977OAI: oai:DiVA.org:kth-145657DiVA: diva2:719476
Updated from manuscript to article in journal.
QC 201410092014-05-262014-05-262014-10-09Bibliographically approved