Fine Control of the Redox Reactivity of a Nonheme Iron(III)-Peroxo Complex by Binding Redox-Inactive Metal Ions

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• 作者：Seong Hee Bae ; Dr. Yong-Min Lee ; Prof. Dr. Shunichi Fukuzumi and Prof. Dr. Wonwoo Nam
• 刊名：Angewandte Chemie International Edition
• 出版年：2017
• 出版时间：January 16, 2017
• 年：2017
• 卷：56
• 期：3
• 页码：801-805
• 全文大小：2219K
• ISSN：1521-3773

文摘

Redox-inactive metal ions are one of the most important co-factors involved in dioxygen activation and formation reactions by metalloenzymes. In this study, we have shown that the logarithm of the rate constants of electron-transfer and C−H bond activation reactions by nonheme iron(III)–peroxo complexes binding redox-inactive metal ions, [(TMC)Fe^III(O₂)]⁺-Mⁿ⁺ (Mⁿ⁺=Sc³⁺, Y³⁺, Lu³⁺, and La³⁺), increases linearly with the increase of the Lewis acidity of the redox-inactive metal ions (ΔE), which is determined from the g_zz values of EPR spectra of O₂^.−-Mⁿ⁺ complexes. In contrast, the logarithm of the rate constants of the [(TMC)Fe^III(O₂)]⁺-Mⁿ⁺ complexes in nucleophilic reactions with aldehydes decreases linearly as the ΔE value increases. Thus, the Lewis acidity of the redox-inactive metal ions bound to the mononuclear nonheme iron(III)–peroxo complex modulates the reactivity of the [(TMC)Fe^III(O₂)]⁺-Mⁿ⁺ complexes in electron-transfer, electrophilic, and nucleophilic reactions.