Synthesis and Characterization of Diiron Thiadithiolate Complexes Related to the Active Site of [FeFe]‐Hydrogenases
Synthesis and Characterization of Diiron Thiadithiolate Complexes Related to the Active Site of [FeFe]‐Hydrogenases
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DOI：
10.1002/ejic.200901023
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发表时间：
2010-03
影响因子：
2.3
通讯作者：
Li-Cheng Song;Qingshan Li;Zhi-Yong Yang;Yupeng Hua;Hongzhu Bian;Q. Hu
中科院分区：
文献类型：
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作者：
Li-Cheng Song;Qingshan Li;Zhi-Yong Yang;Yupeng Hua;Hongzhu Bian;Q. Hu
在通过[(μ-LiS) 2 Fe 2 (CO) 6 ]与过量S(CH 2 Br) 2 缩合的新方法制备已知络合物[Fe 2 (μ-SCH 2 ) 2 S(CO) 6 ] (A)的基础上，通过CO配体的取代和中心S原子的配位，合成了12种新的二铁硫代二硫醇作为[FeFe]-氢化酶活性位点的模拟物。用适当的试剂制备复合物A。用1当量处理A。单齿配体PPh 3 和[(η 5 -C 5 H 5 )(η 5 -Ph 2 PC 5 H 4 )-Fe]在Me 3 NO存在下和1当量的情况下的合成。 tBuNC 和环己基异氰化物得到单个 [2Fe3S] 簇的单取代络合物 [Fe 2 (p-SCH 2 ) 2 S(CO) 5 -(L 1 )] (1, L 1 = PPh 3 ; 2, L 1 = (η 5 -C 5 H 5 )(η 5 -Ph 2 PC 5 H 4 )Fe; 3, L 1 = tBuNC; 4, L 1 = C 6 H 11 NC)，而含双[2Fe3S]簇的双取代络合物 [(Fe 2 (μ-SCH 2 ) 2 S-(CO) 5 } 2 (L 2 )] [5, L 2 = 4,4'-(Ph 2 P) 2 (C 6 H 4 ) 2 ; 6, L 2 =反式-Ph 2 P-CH=CHPPh 2 ; 7, L 2 = 1,4-(CN) 2 C 6 H 4 ; 8, L 2 = (η 5 -Ph 2 PC 5 H 4 ) 2 -Fe ; 9, L 2 = (η 5 -Ph 2 PC 5 H 4 ) 2 Ru]由A与0.5当量的相应二齿化合物反应生成。此外，中心S原子配位的含单个[2Fe3S]簇的配合物，[{Fe 2 (μ-SCH 2 ) 2 S(CO) 6 }{(η 5 -MeC 5 H 4 )(CO) 2 Fe}(BF4)] (10)，[(Fe 2 (μ-SCH 2 ) 2 S(CO) 6 }(Cr(CO) 5 }] (11)和[{Fe 2 (μ-SCH 2 ) 2 S(CO) 6 }[W(CO) 5 }] (12)，可以通过配合物A与原位制备的[{(η 5 -MeC 5 H 4 )(CO) 2 -Fe}(BF 4 )]、[Cr(CO) 5 (thf)]反应得到，虽然发现配合物 3 能够还原弱酸 Et 3 NHCl 的质子生成 H 2 ，但 X 射线晶体学研究证实 (i) 1 和 8 中的磷烷配体的每个 P 原子占据 Fe 原子的顶端位置，(ii) 3 中的异氰化物配体位于 Fe 原子的基础位置，以及 (iii) (η 5) 10-12中的-MeC 5 H 4 )(CO) 2 Fe、Cr(CO) 5 和W(CO) 5 单元通过来自其[2Fe3S]簇核的两个稠合六元环的赤道键连接至配合物A的中心S原子。
On the basis of preparation of the known complex [Fe 2 (μ-SCH 2 ) 2 S(CO) 6 ] (A) by a new method involving condensation of [(μ-LiS) 2 Fe 2 (CO) 6 ] with excess S(CH 2 Br) 2 , twelve new diiron thiadithiolates as mimics of the [FeFe]-hydrogenase active site have been synthesized by substitution of the CO ligand and coordination at the central S atom of complex A with appropriate reagents. Treatment of A with 1 equiv. of the monodentate ligands PPh 3 and [(η 5 -C 5 H 5 )(η 5 -Ph 2 PC 5 H 4 )-Fe] in the presence of Me 3 NO and with 1 equiv. tBuNC and cyclohexyl isocyanide gave the single [2Fe3S]-cluster-containing monosubstituted complexes [Fe 2 (p-SCH 2 ) 2 S(CO) 5 -(L 1 )] (1, L 1 = PPh 3 ; 2, L 1 = (η 5 -C 5 H 5 )(η 5 -Ph 2 PC 5 H 4 )Fe; 3, L 1 = tBuNC; 4, L 1 = C 6 H 11 NC), whereas the double [2Fe3S]-cluster-containing disubstituted complexes [(Fe 2 (μ-SCH 2 ) 2 S-(CO) 5 } 2 (L 2 )] [5, L 2 = 4,4'-(Ph 2 P) 2 (C 6 H 4 ) 2 ; 6, L 2 = trans-Ph 2 P-CH=CHPPh 2 ; 7, L 2 = 1,4-(CN) 2 C 6 H 4 ; 8, L 2 = (η 5 -Ph 2 PC 5 H 4 ) 2 -Fe ; 9, L 2 = (η 5 -Ph 2 PC 5 H 4 ) 2 Ru] were produced by reaction of A with 0.5 equiv. of the corresponding bidentate ligands in the presence of Me 3 NO. In addition, the single [2Fe3S]-cluster-containing complexes in which the central S atom is coordinated, [{Fe 2 (μ-SCH 2 ) 2 S(CO) 6 }{(η 5 -MeC 5 H 4 )(CO) 2 Fe}(BF4)] (10), [(Fe 2 (μ-SCH 2 ) 2 S(CO) 6 }(Cr(CO) 5 }] (11), and [{Fe 2 (μ-SCH 2 ) 2 S(CO) 6 }[W(CO) 5 }] (12), could be obtained by reaction of complex A with the in situ prepared [{(η 5 -MeC 5 H 4 )(CO) 2 -Fe}(BF 4 )], [Cr(CO) 5 (thf)], and [W(CO) 5 (thf)], respectively. While complex 3 was found to be able to reduce the proton of the weak acid Et 3 NHCl to give H 2 , the X-ray crystallographic study confirmed that (i) each P atom of the phosphane ligands in 1 and 8 occupies an apical position at the Fe atoms, (ii) the isocyanide ligand in 3 lies in a basal position of the Fe atom, and (iii) the (η 5 -MeC 5 H 4 )(CO) 2 Fe, Cr(CO) 5 , and W(CO) 5 units in 10-12 are linked to the central S atom of complex A by an equatorial bond from the two fused six-membered rings of their [2Fe3S]-cluster cores.