Unsaturated, mixed-valence diiron dithiolate model for the Hox state of the [FeFe] hydrogenase
Unsaturated, mixed-valence diiron dithiolate model for the Hox state of the [FeFe] hydrogenase
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DOI：
10.1002/anie.200702224
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发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Wilson, Scott R.
中科院分区：
文献类型：
--
作者：
Justice, Aaron K.;Rauchfuss, Thomas B.;Wilson, Scott R.
[FeFe]氢化酶是已知用于将质子还原成H2的最有效的催化剂。[1]活性位点以两种功能状态存在（方案1），S= 0的Hred和S= 1/2的Hox。[2]该领域的研究旨在阐明酶催化的机制，并利用这些信息开发无蛋白质的生物合成催化剂。[3]一个具体的研究目标是制备类似于活性位点的功能状态的分子，期望功能遵循形式。大多数关于二硫羟羰基二铁配合物的研究依赖于有机配体（如膦）来代替天然存在的氰化物和μ-SR [Fe 4S 4]配体，[4]它们具有复杂的酸碱行为，通常难以在蛋白质之外控制。模拟的另一个障碍是具有适当结构、稳定性和反应性的混合价二硫代二铁化合物的稀缺性。在二硫代二铁模型中混合价的第一个证据是在[Fe 2-{（SCH 2）2CMeCH 2SMe}（CN）2（CO）4] 2 H2O的单电子氧化中获得的，这提供了一种热敏混合价衍生物，其IR和EPR光谱特征类似于CO抑制酶的那些。[5]在最近的工作中，[Fe 2-（S2 C3 H6）（CO）4（PMe 3）L1]（L1= 1，3-双（2，4，6-三甲基苯基）咪唑-2-亚基）的氧化显示出混合价
The [FeFe] hydrogenase enzymes are the most efficient catalysts known for the reduction of protons to H2.[1] The active site exists in two functional states (Scheme 1), Hred, which is S= 0, and Hox, which is S= 1/2.[2] Research in this area is aimed at elucidating the mechanism of the enzymatic catalysis and at using this information to develop protein-free bioinspired synthetic catalysts.[3] A specific research goal is the preparation of molecules that resemble the functional states of the active site with the expectation that function will follow form. Most studies on diiron dithiolato carbonyl complexes rely on organic ligands (eg phosphanes) in place of the naturally occurring cyanide and μ-SR [Fe4S4] ligands,[4] which have complicated acid–base behavior that is often difficult to control outside of the protein. Another barrier to modeling has been the rarity of mixed-valence diiron dithiolate compounds with the appropriate structures, stability, and reactivity.The first evidence for mixed valency in diiron dithiolate models was obtained in the one-electron oxidation of [Fe2-{(SCH2) 2CMeCH2SMe}(CN) 2 (CO) 4] 2À, which afforded a thermally sensitive mixed-valence derivative with IR and EPR spectroscopy signatures resembling those for the CO-inhibited enzyme.[5] In very recent work, the oxidation of [Fe2-(S2C3H6)(CO) 4 (PMe3) L1](L1= 1, 3-bis (2, 4, 6-trimethylphenyl) imidazol-2-ylidene) was shown to give a mixed-valence