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钼-铁-硫团簇中氮的结合和活化
作者:小柯机器人 发布时间:2021/5/30 14:23:22

美国麻省理工学院Daniel L. M. Suess研究小组提出了钼-铁-硫团簇中氮的结合和活化。 2021年5月27日出版的《自然化学》发表了这项成果。

本文报道,在保护性配体环境中嵌入[MoFe3S4]聚合体可以使N2与Fe结合。所制备的桥接[MoFe3S4]2(μ-η1:η1-N2)配合物的N-N键明显减弱,尽管金属中心具有较高的形式氧化态。用一个正电的Ti金属自由基取代[MoFe3S4]古巴烷之一,会引起额外的电荷转移到N2配体上,并产生Fe–N多键特征。

结构和光谱分析表明,N2活化伴随着Fe-S距离的缩短和各Fe位点(包括那些不直接与N2结合的位点)的电荷转移。这些结果表明,簇内的共价相互作用在N2的结合和活化中起着关键作用。

据悉,固氮酶的Fe-S簇进行了氮气到NH3的终身持续转化。尽管在建模固氮酶辅助因子的结构方面仍继续取得进展,但尚未显示合成的Fe–S簇能够与N2形成明确定义的配位化合物。

附:英文原文

Title: Dinitrogen binding and activation at a molybdenum–iron–sulfur cluster

Author: Alex McSkimming, Daniel L. M. Suess

Issue&Volume: 2021-05-27

Abstract: The Fe–S clusters of nitrogenases carry out the life-sustaining conversion of N2 to NH3. Although progress continues to be made in modelling the structural features of nitrogenase cofactors, no synthetic Fe–S cluster has been shown to form a well-defined coordination complex with N2. Here we report that embedding an [MoFe3S4] cluster in a protective ligand environment enables N2 binding at Fe. The bridging [MoFe3S4]2(μ-η1:η1-N2) complex thus prepared features a substantially weakened N–N bond despite the relatively high formal oxidation states of the metal centres. Substitution of one of the [MoFe3S4] cubanes with an electropositive Ti metalloradical induces additional charge transfer to the N2 ligand with generation of Fe–N multiple-bond character. Structural and spectroscopic analyses demonstrate that N2 activation is accompanied by shortened Fe–S distances and charge transfer from each Fe site, including those not directly bound to N2. These findings indicate that covalent interactions within the cluster play a critical role in N2 binding and activation.

DOI: 10.1038/s41557-021-00701-6

Source: https://www.nature.com/articles/s41557-021-00701-6

期刊信息

Nature Chemistry:《自然—化学》,创刊于2009年。隶属于施普林格·自然出版集团,最新IF:21.687
官方网址:https://www.nature.com/nchem/
投稿链接:https://mts-nchem.nature.com/cgi-bin/main.plex