Zhu Chengxu, D'Agostino Carmine, de Visser Sam P
Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom.
Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom.
Chemistry. 2023 Nov 13;29(63):e202302832. doi: 10.1002/chem.202302832. Epub 2023 Oct 20.
CO utilization is an important process in the chemical industry with great environmental power. In this work we show how CO and H can be reacted to form methanol on an iron(II) center and highlight the bottlenecks for the reaction and what structural features of the catalyst are essential for efficient turnover. The calculations predict the reactions to proceed through three successive reaction cycles that start with heterolytic cleavage of H followed by sequential hydride and proton transfer processes. The H splitting process is an endergonic process and hence high pressures will be needed to overcome this step and trigger the hydrogenation reaction. Moreover, H cleavage into a hydride and proton requires a metal to bind hydride and a nearby source to bind the proton, such as an amide or pyrazolyl group, which the scorpionate ligand used here facilitates. As such the computations highlight the non-innocence of the ligand scaffold through proton shuttle from H to substrate as an important step in the reaction mechanism.
一氧化碳（CO）的利用是化学工业中的一个重要过程，具有巨大的环境影响力。在这项工作中，我们展示了CO和H如何在铁（II）中心上反应生成甲醇，并突出了该反应的瓶颈以及催化剂的哪些结构特征对于高效转化至关重要。计算预测反应通过三个连续的反应循环进行，起始于H的异裂，随后是连续的氢化物和质子转移过程。H分裂过程是一个吸能过程，因此需要高压来克服这一步骤并引发氢化反应。此外，H裂解为氢化物和质子需要金属结合氢化物以及附近的源来结合质子，例如酰胺或吡唑基，这里使用的蝎形配体有助于实现这一点。因此，计算突出了配体支架通过从H到底物的质子穿梭的非无害性，这是反应机理中的一个重要步骤。
