Enhancement in catalytic proton reduction by an internal base in a diiron pentacarbonyl complex: its synthesis, characterisation, inter-conversion and electrochemical investigation
Enhancement in catalytic proton reduction by an internal base in a diiron pentacarbonyl complex: its synthesis, characterisation, inter-conversion and electrochemical investigation
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二铁五羰基络合物中内部碱增强催化质子还原：其合成、表征、相互转化和电化学研究
DOI：
10.1039/c6dt04409c
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发表时间：
2017
影响因子：
4
通讯作者：
Liu Xiaoming
中科院分区：
文献类型：
--
作者：
Li Zhimei;Xiao Zhiyin;Xu Fenfen;Zeng Xianghua;Liu Xiaoming
三脚架配体（H2 L）与{S2 N}供体集与三铁十二羰基在甲苯中的反应导致分离的二铁五羰基配合物1作为模型的子网站的[FeFe]-氢化酶。该配合物在CO（1个大气压）下的质子化定量地形成具有侧基吡啶鎓基团的六羰基络合物2 H+。红外光谱研究表明，它的吡啶侧基解离，得到六羰基配合物2，随后形成五羰基配合物1。研究了这些配合物的电化学性质。配合物2 H+在质子还原上表现出电催化作用，与其他中性六羰基二铁配合物相比，其电位正200 mV以上。这种催化作用在CO气氛下通过释放在催化作用中充当质子中继的结合的碱基而增强。
The reaction of a tripodal ligand (H2L) with a {S2N} donor-set with tri-iron dodecacarbonyl in toluene leads to the isolation of a diiron pentacarbonyl complex 1 as a model for the sub-site of the [FeFe]-hydrogenase. Protonation of this complex under CO (1 atm.) forms quantitatively the hexacarbonyl complex 2H+ with a pendant pyridinium group. Infrared spectroscopic investigations indicate that its pendant pyridinium group dissociates to give hexacarbonyl complex 2 which forms subsequently the pentacarbonyl complex 1. The electrochemistry of these complexes has been investigated. Complex 2H+ exhibits electrocatalysis on proton reduction at a potential more positive by over 200 mV compared to that for other neutral diiron hexacarbonyl complexes. This catalysis is enhanced under a CO atmosphere by freeing the bound base group which acts as a proton relay in the catalysis.