Synthesis and Characterization of Diiron Diselenolato Complexes Including Iron Hydrogenase Models
Synthesis and Characterization of Diiron Diselenolato Complexes Including Iron Hydrogenase Models
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DOI：
10.1021/om800748p
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发表时间：
2009-02-23
期刊：
影响因子：
2.8
通讯作者：
Weigand, Wolfgang
中科院分区：
文献类型：
--
作者：
Harb, Mohammad K.;Niksch, Tobias;Weigand, Wolfgang
二铁二硒醇配合物已被制备为[FeFe]-氢化酶的活性中心的模型。Fe-3（CO）（12）与1当量的1，3-二硒氰基丙烷（1）在THF中回流反应得到模型化合物Fe-2（mu-Se_2C_3 H_6）（CO）（6）（2），产率68%。由Fe-3（CO）（1,2）与原位生成的化合物3-甲基-1，2-二硒环戊烷（4）反应得到类似的甲基取代配合物Fe-2（mu-Se 2C 3 H5 CH 3）（CO）（6）（3）。相反，Fe-3（CO）（12）与1，3，5-三硒环己烷（5）的反应产生Fe-2（mu（2），kappa-Se，C-SeCH 2SeCH 2）（CO）（6）（6），Fe-2[（mu-SeCH 2）（2）Se]（CO）（6）（7）的混合物。和Fe-2（mu-Se 2CH 2）（CO）（6）（8）。化合物2、3、6和7通过IR、H-1、C-13、Se-77 NMR、质谱、元素分析和X-射线单晶结构分析进行了表征。报道了3的He I和He 11光电子能谱，并借助密度泛函理论计算进一步分析了其电子结构。计算的3的阳离子的“旋转”，其中有一个半桥羰基配体的重组能，是小于类似的配合物与硫，而不是硒。配合物2和3分别被证明是弱酸特戊酸和乙酸中质子电化学还原生成氢气的催化剂。
Diiron diselenolato complexes have been prepared as models of the active site of [FeFe]-hydrogenases. Treatment of Fe-3(CO)(12) with 1 equiv of 1,3-diselenocyanatopropane (1) in THF at reflux afforded the model compound Fe-2(mu-Se2C3H6)(CO)(6) (2) in 68% yield. The analogous methyl-substituted complex, Fe-2(mu-Se2C3H5CH3)(CO)(6) (3), was obtained from the reaction of Fe-3(CO)(12) with the in situ generated compound 3-methyl-1,2-diselenolane (4). In contrast, the reaction of Fe-3(CO)(12) with 1,3,5-triselenacyclohexane (5) produced a mixture of Fe-2(mu(2),kappa-Se,C-SeCH2SeCH2)(CO)(6) (6), Fe-2[(mu-SeCH2)(2)Se](CO)(6) (7). and Fe-2(mu-Se2CH2)(CO)(6) (8). Compounds 2, 3, 6, and 7 were characterized by IR, H-1, C-13; and Se-77 NMR spectroscopy, mass spectrometry, elemental analysis, and X-ray single-crystal structure analysis. The He I and He 11 photoelectron spectra for 3 are reported, and the electronic structure is further analyzed with the aid of DFT computations. The calculated reorganization energy of the cation of 3 to the "rotated" which has a semibridging carbonyl ligand, is less than that of the analogous complexes with sulfur instead of selenium. Complexes 2 and 3 have been proved to be catalysts for electrochemical reduction of protons from the weak acids pivalic and acetic acid, respectively, to give hydrogen.