Synthesis and characterization of a family of binuclear non-heme iron monooxygenase model compounds: Evidence for a "phenolate/amide carbonyl (PAC) shift" upon oxidation

被引：18

作者：

Cappillino, Patrick J. ^{[1
]}

Tarves, Paul C. ^{[1
]}

Rowe, Gerard T. ^{[1
]}

Lewis, Andrew J. ^{[1
]}

Harvey, Mark ^{[1
]}

Rogge, Corina ^{[2
]}

Stassinopoulos, Adonis ^{[2
]}

Lo, Wayne ^{[3
]}

Armstrong, William H. ^{[3
]}

Caradonna, John P. ^{[1
]}

机构：

[1] Boston Univ, Dept Chem, Boston, MA 02215 USA

[2] Yale Univ, Dept Chem, New Haven, CT 06511 USA

[3] Boston Coll, Dept Chem, Chestnut Hill, MA 02467 USA

来源：

INORGANICA CHIMICA ACTA | 2009年 / 362卷 / 07期

基金：

美国国家科学基金会;

关键词：

Binuclear iron; Non-heme iron; Carboxylate shift; sMMO; Di-mu-alkoxy diferric; Dioxygen activation; RIBONUCLEOTIDE REDUCTASE R2; BRIDGED IRON(III) COMPLEXES; TYROSYL RADICAL COFACTOR; METHANE MONOOXYGENASE; CRYSTAL-STRUCTURES; OXYGEN ACTIVATION; ESCHERICHIA-COLI; DIAMOND CORE; ACTIVE-SITE; DIOXYGEN ACTIVATION;

D O I：

10.1016/j.ica.2008.09.036

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

A series of binuclear iron compounds has been synthesized using diamide, bis-phenolate ligands in which the carbon-linker between the amide nitrogen atoms has been varied. Two diferrous compounds in the series, Fe-2(II)(H(2)Hbach)(2)(N-MeIM)(2) and Fe-2(II)(H(2)Hbame)(2)(N-MeIM)(2) along with their two-electron oxidized, di-mu-methoxy-bridged counterparts, Fe-III(H(2)Hbach)(2)(OMe)(2) and Fe-III(H(2)Hbame)(2)(OMe)(2) have been crystallographically characterized, as have the di-mu-methoxy compounds Fe-2(III)(H(2)Hbap)(2)(OMe)(2); Fe-2(III)(H(2)Hbabn)(2)(OMe)(2) and Fe-2(III)(H(2)Hbapen)(2)(OMe)(2) (H(2)Hbab = 1,2-bis(2-hydroxybenzamido) benzene, H(2)Hbach = trans-1,2-bis(2-hydroxybenzamido) cyclohexane, H(2)Hbame = 1,2-bis(2-hydroxybenzamido) ethane, H(2)Hbap = 1,3-bis(2-hydroxybenzamido) propane, H(2)Hbabn = 1,4-bis(2-hydroxybenzamido) butane, H(2)Hbapen = 1,5-bis(2-hydroxybenzamido) pentane, N-MeIM = N-methylimidazole and OMe = methoxide). Fe-2(II)(H(2)Hbach)(2)(N-MeIM)(2) and Fe-2(II)(H(2)Hbame)(2)(N-MeIM)(2) are structurally very similar to previously reported diferrous compounds of this family of ligands that have been shown to be active as oxygen atom transfer catalysts. Flexibility in the carbon-linker allows some variability in the orientation of the phenolate arms of the ligands in the diferric di-mu-methoxy compounds, but the Fe2O2 core remains largely unchanged across the series. Two-electron oxidation of the ferrous compounds in methanol shows a substantial ligand rearrangement that is consistent with other spectroscopic, electrochemical and kinetic investigations. The loss of both phenolate bridges upon oxidation is reminiscent of the "carboxylate shift" observed in binuclear non-heme enzymes and could provide insight into the driving force behind this family of compounds' function as a catalyst. (c) 2008 Elsevier B. V. All rights reserved.

引用

页码：2136 / 2150

页数：15

共 53 条

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