View : 57 Download: 0

Lewis Acid Coupled Electron Transfer of Metal-Oxygen Intermediates

Title
Lewis Acid Coupled Electron Transfer of Metal-Oxygen Intermediates
Authors
Fukuzumi, ShunichiOhkubo, KeiLee, Yong-MinNam, Wonwoo
Ewha Authors
남원우이용민Shunichi FukuzumiKei Okubo
SCOPUS Author ID
남원우scopus; Shunichi Fukuzumiscopus; Kei Okuboscopus
Issue Date
2015
Journal Title
CHEMISTRY-A EUROPEAN JOURNAL
ISSN
0947-6539JCR Link1521-3765JCR Link
Citation
vol. 21, no. 49, pp. 17548 - 17559
Keywords
electron transferLewis acidsmetal-oxo complexesmetal-peroxo complexessuperoxides
Publisher
WILEY-V C H VERLAG GMBH
Indexed
SCI; SCIE; SCOPUS WOS scopus
Abstract
Redox-inactive metal ions and Bronsted acids that function as Lewis acids play pivotal roles in modulating the redox reactivity of metal-oxygen intermediates, such as metal-oxo and metal-peroxo complexes. The mechanisms of the oxidative C-H bond cleavage of toluene derivatives, sulfoxidation of thioanisole derivatives, and epoxidation of styrene derivatives by mononuclear nonheme iron(IV)-oxo complexes in the presence of triflic acid (HOTf) and Sc(OTf)(3) have been unified as rate-determining electron transfer coupled with binding of Lewis acids (HOTf and Sc(OTf)(3)) by iron(III)-oxo complexes. All logarithms of the observed second-order rate constants of Lewis acid-promoted oxidative C-H bond cleavage, sulfoxidation, and epoxidation reactions of iron(IV)-oxo complexes exhibit remarkably unified correlations with the driving forces of proton-coupled electron transfer (PCET) and metal ion-coupled electron transfer (MCET) in light of the Marcus theory of electron transfer when the differences in the formation constants of precursor complexes were taken into account. The binding of HOTf and Sc(OTf)(3) to the metal-oxo moiety has been confirmed for Mn-IV-oxo complexes. The enhancement of the electron-transfer reactivity of metal-oxo complexes by binding of Lewis acids increases with increasing the Lewis acidity of redox-inactive metal ions. Metal ions can also bind to mononuclear nonheme iron(III)-peroxo complexes, resulting in acceleration of the electron-transfer reduction but deceleration of the electron-transfer oxidation. Such a control on the reactivity of metal-oxygen intermediates by binding of Lewis acids provides valuable insight into the role of Ca2+ in the oxidation of water to dioxygen by the oxygen-evolving complex in photosystem II.
DOI
10.1002/chem.201502693
Appears in Collections:
자연과학대학 > 화학·나노과학전공 > Journal papers
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE