Lee YM, Bang S, Kim YM, Cho J, Hong S, Nomura T, Ogura T, Tröppner O, Ivanovic-Burmazovic I, Sarangi R, Fukuzumi S, Nam W (2013)
Publication Type: Journal article, Original article
Publication year: 2013
Original Authors: Lee Y., Bang S., Kim Y., Cho J., Hong S., Nomura T., Ogura T., Troeppner O., Ivanović-Burmazović I., Sarangi R., Fukuzumi S., Nam W.
Publisher: Royal Society of Chemistry
Book Volume: 4
Pages Range: 3917-3923
Journal Issue: 10
DOI: 10.1039/c3sc51864g
Redox-inactive metal ions that function as Lewis acids play pivotal roles in modulating reactivities of oxygen-containing metal complexes in a variety of biological and biomimetic reactions, including dioxygen activation/formation and functionalization of organic substrates. Mononuclear nonheme iron(iii)-peroxo species are invoked as active oxygen intermediates in the catalytic cycles of dioxygen activation by nonheme iron enzymes and their biomimetic compounds. Here, we report mononuclear nonheme iron(iii)-peroxo complexes binding redox-inactive metal ions, [(TMC)Fe(O)] -M (M = Sc and Y ; TMC = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane), which are characterized spectroscopically as a 'side-on' iron(iii)-peroxo complex binding a redox-inactive metal ion, (TMC)Fe-(μ, η:η-O)-M (2-M). While an iron(iii)-peroxo complex, [(TMC)Fe(O)], does not react with electron donors (e.g., ferrocene), one-electron reduction of the iron(iii)-peroxo complexes binding redox-inactive metal ions occurs readily upon addition of electron donors, resulting in the generation of an iron(iv)-oxo complex, [(TMC)Fe(O)] (4), via heterolytic O-O bond cleavage of the peroxide ligand. The rates of the conversion of 2-M to 4 are found to depend on the Lewis acidity of the redox-inactive metal ions and the oxidation potential of the electron donors. We have also determined the fundamental electron-transfer properties of 2-M, such as the reduction potential and the reorganization energy in electron-transfer reaction. Based on the results presented herein, we have proposed a mechanism for the reactions of 2-M and electron donors; the reduction of 2-M to the reduced species, (TMC)Fe-(O)-M (2′-M), is the rate-determining step, followed by heterolytic O-O bond cleavage of the reduced species to form 4. The present results provide a biomimetic example demonstrating that redox-inactive metal ions bound to an iron(iii)-peroxo intermediate play a significant role in activating the peroxide O-O bond to form a high-valent iron(iv)-oxo species. © 2013 The Royal Society of Chemistry.
APA:
Lee, Y.-M., Bang, S., Kim, Y.M., Cho, J., Hong, S., Nomura, T.,... Nam, W. (2013). A mononuclear nonheme iron(iii)-peroxo complex binding redox-inactive metal ions. Chemical Science, 4(10), 3917-3923. https://dx.doi.org/10.1039/c3sc51864g
MLA:
Lee, Yong-Min, et al. "A mononuclear nonheme iron(iii)-peroxo complex binding redox-inactive metal ions." Chemical Science 4.10 (2013): 3917-3923.
BibTeX: Download