Active-site models for iron hydrogenases: Reduction chemistry of dinuclear iron complexes
Active-site models for iron hydrogenases: Reduction chemistry of dinuclear iron complexes
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DOI：
10.1021/ic0610381
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发表时间：
2006-10-02
影响因子：
4.6
通讯作者：
Heinekey, D. Michael
中科院分区：
文献类型：
--
作者：
de Carcer, Inigo Aguirre;DiPasquale, Antonio;Heinekey, D. Michael
在四氢呋喃中，用1当量的十甲基钴茂（Cp*Co₂）还原Fe₂(μ - S₂C₃H₆)(CO)₆（1），得到一个四核二价阴离子2。2的溶液和固态样品的红外光谱在1736 cm⁻¹处有一个吸收带，表明存在桥连羰基（CO）配体。X射线晶体学证实2的结构由两个Fe₂单元组成，它们通过一个丙二硫醇盐部分桥连，其化学式为[Fe₂(μ - S₂C₃H₆)(CO)₅(SCH₂CH₂CH₂ - μ - S)Fe₂(μ - CO)(CO)₆]²⁻。其中一个Fe₂单元有一个桥连CO配体和六个端基CO配体。第二个亚单元呈现一个桥连的丙二硫醇盐部分。一个CO配体被一个端基硫醇盐配体取代，复制了唯铁氢化酶的基本结构。通过用2当量的[Cp₂Fe][PF₆]处理2，还原反应可以逆转，以接近定量的产率重新形成配合物1。配合物2也可以被对甲苯磺酸等酸氧化，重新生成配合物1并形成H₂。
Reduction of Fe-2(mu-S2C3H6)(CO)(6) (1) in tetrahydrofuran with 1 equiv of decamethylcobaltocene (Cp*Co-2) affords a tetranuclear dianion 2. The IR spectra of samples of 2 in solution and in the solid state exhibit a band at 1736 cm(-1), suggestive of the presence of a bridging carbonyl (CO) ligand. X-ray crystallography confirms that the structure of 2 consists of two Fe2 units bridged by a propanedithiolate moiety formulated as [Fe-2(mu-S2C3H6)(CO)(5)(SCH2CH2CH2-mu-S)Fe-2(mu-CO)(CO)(6)](2-). One of the Fe-2 units has a bridging CO ligand and six terminal CO ligands. The second subunit exhibits a bridging propanedithiolate moiety. One CO ligand has been replaced by a terminal thiolate ligand, replicating the basic architecture of Fe-only hydrogenases. The reduction reaction can be reversed by treatment of 2 with 2 equiv of [Cp2Fe][PF6], reforming complex 1 in near-quantitative yield. Complex 2 can also be oxidized by acids such as p-toluenesulfonic acid, regenerating complex 1 and forming H-2.