Dioxygen Binding to Complexes with FeII2(-OH)2 Cores: Steric Control of Activation Barriers and O
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- 作者：Sergey V. Kryatov ; Sonia Taktak ; Ivan V. Korendovych ; Elena V. Rybak-Akimova ; Jó ; zsef Kaizer ; Sté ; phane Torelli ; Xiaopeng Shan ; Sanjay Mandal ; Vicki L. MacMurdo ; Antoni Mairata i Payeras
- 刊名：Inorganic Chemistry
- 出版年：2005
- 出版时间：January 10, 2005
- 年：2005
- 卷：44
- 期：1
- 页码：85 - 99
- 全文大小：351K
- 年卷期：v.44,no.1(January 10, 2005)
- ISSN：1520-510X
文摘
A series of complexes with [FeII2(
-OH)2] cores has been synthesized with N3 and N4 ligands and structurallycharacterized to serve as models for nonheme diiron(II) sites in enzymes that bind and activate O2. These complexesreact with O2 in solution via bimolecular rate-limiting steps that differ in rate by 103-fold, depending on liganddenticity and steric hindrance near the diiron center. Low-temperature trapping of a (-oxo)(-1,2-peroxo)diiron(III)intermediate after O2 binding requires sufficient steric hindrance around the diiron center and the loss of a proton(presumably that of a hydroxo bridge or a yet unobserved hydroperoxo intermediate). The relative stability of theseand other (-1,2-peroxo)diiron(III) intermediates suggests that these species may not be on the direct pathway fordioxygen activation.
-OH)2] cores has been synthesized with N3 and N4 ligands and structurallycharacterized to serve as models for nonheme diiron(II) sites in enzymes that bind and activate O2. These complexesreact with O2 in solution via bimolecular rate-limiting steps that differ in rate by 103-fold, depending on liganddenticity and steric hindrance near the diiron center. Low-temperature trapping of a (-oxo)(-1,2-peroxo)diiron(III)intermediate after O2 binding requires sufficient steric hindrance around the diiron center and the loss of a proton(presumably that of a hydroxo bridge or a yet unobserved hydroperoxo intermediate). The relative stability of theseand other (-1,2-peroxo)diiron(III) intermediates suggests that these species may not be on the direct pathway fordioxygen activation.