Hydrophilic Quaternary Ammonium-Group-Containing [FeFe]-Hydrogenase Models: Synthesis, Structures, and Electrocatalytic Hydrogen Production.
Hydrophilic Quaternary Ammonium-Group-Containing [FeFe]-Hydrogenase Models: Synthesis, Structures, and Electrocatalytic Hydrogen Production.
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DOI：
10.1002/chem.201603040
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发表时间：
2016-11
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影响因子：
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通讯作者：
Li-Cheng Song;Yong-Xiang Wang;Xu-Kang Xing;Shu-Da Ding;Long-Duo Zhang;Xu-Yong Wang;Hongtao Zhang
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文献类型：
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作者：
Li-Cheng Song;Yong-Xiang Wang;Xu-Kang Xing;Shu-Da Ding;Long-Duo Zhang;Xu-Yong Wang;Hongtao Zhang
将前体[(μ-PDT)Fe2 (CO)4 {κ2 -(Ph2 P)2 N(CH2)2 NMe2 BzBr}](1)和[(μ-PDT)Fe2 (CO)4 {κ2 -(Ph2 P)2 N(CH2)2 NMe2 BzBr}](3)与苄基溴进行季铵化反应，制备了第一个季铵盐含[FeFe]氢化酶模型[(μ-PDT)Fe2 (CO)4 {κ2 -(Ph2 P)2 N(CH2)2 NMe2 BzBr}] （2； PDT=propanedithiolate）和[(μ-PDT)Fe2 (CO)4 {κ2 -(Ph2 P)2 N(CH2)2 NMe2}](4)。虽然新的配合物1-4已经通过光谱和x射线晶体学研究得到了充分的表征，但螯合配合物1和2在较高温度下转化为桥接异构体3和4，从而表明这些桥接异构体在热力学上是有利的。以MeCN和MeCN/H2 O为溶剂对亲水性模型2和4的电化学研究表明，随着水含量的增加，还原电位向负电位转移。这一结果表明，2和4在混合MeCN/H2 O溶剂中比在MeCN中更容易被还原。此外，亲水性模型2和4作为电催化剂，在MeCN/H2 O作为溶剂中获得比MeCN更高的icat /ip值和周转数（吨），用于弱酸HOAc制氢。
The first quaternary ammonium-group-containing [FeFe]-hydrogenase models [(μ-PDT)Fe2 (CO)4 {κ2 -(Ph2 P)2 N(CH2 )2 NMe2 BzBr}] (2; PDT=propanedithiolate) and [(μ-PDT)Fe2 (CO)4 {μ-(Ph2 P)2 N(CH2 )2 NMe2 BzBr}] (4) have been prepared by the quaternization of their precursors [(μ-PDT)Fe2 (CO)4 {κ2 -(Ph2 P)2 N(CH2 )2 NMe2 }] (1) and [(μ-PDT)Fe2 (CO)4 {μ-(Ph2 P)2 N(CH2 )2 NMe2 }] (3) with benzyl bromide in high yields. Although new complexes 1-4 have been fully characterized by spectroscopic and X-ray crystallographic studies, the chelated complexes 1 and 2 converted into their bridged isomers 3 and 4 at higher temperatures, thus demonstrating that these bridged isomers are thermodynamically favorable. An electrochemical study on hydrophilic models 2 and 4 in MeCN and MeCN/H2 O as solvents indicates that the reduction potentials are shifted to less-negative potentials as the water content increases. This outcome implies that both 2 and 4 are more easily reduced in the mixed MeCN/H2 O solvent than in MeCN. In addition, hydrophilic models 2 and 4 act as electrocatalysts and achieve higher icat /ip values and turnover numbers (TONs) in MeCN/H2 O as a solvent than in MeCN for the production of hydrogen from the weak acid HOAc.