Liu Yuting, Su Xiaofang, Guan Wei, Yan Likai
Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, Changchun, P. R. China.
Phys Chem Chem Phys. 2020 Mar 7;22(9):5249-5254. doi: 10.1039/c9cp05893a. Epub 2020 Feb 24.
In this work, the mechanism of water oxidation catalyzed by an Ru-based complex [Ru(L)] (L = 5,5-chelated 2-carboxyl-phen, 2,2';6',2''-terpyridine) was studied by density functional theory (DFT) calculations. In [Ru(L)], a carboxyl group is included in the second coordination sphere and plays an important role in the catalytic process. In the oxidation activation stage of water oxidation catalysis, the carboxyl group is proposed as a promising proton acceptor to promote proton transfer, which results in active Ru[double bond, length as m-dash]O species. Then, O-O bond formation can proceed via water nucleophilic attack (WNA) or oxo-oxo coupling mechanisms. In the O release stage, similar to the oxidation activation process, the carboxyl group promotes proton transfer as a promising proton acceptor. In the present work, the favorable mechanism is WNA that involves proton transfer to the carboxyl group. It is expected that this work will provide meaningful information for synthesizing excellent water oxidation catalysts (WOCs).
在这项工作中，通过密度泛函理论（DFT）计算研究了基于钌的配合物[Ru(L)]（L = 5,5-螯合的2-羧基苯酚，2,2';6',2''-三联吡啶）催化水氧化的机理。在[Ru(L)]中，一个羧基包含在第二配位层中，并在催化过程中起重要作用。在水氧化催化的氧化活化阶段，羧基被认为是促进质子转移的有前景的质子受体，这导致形成活性Ru=O物种。然后，O-O键的形成可以通过水亲核攻击（WNA）或氧-氧偶联机制进行。在氧释放阶段，与氧化活化过程类似，羧基作为有前景的质子受体促进质子转移。在本工作中，有利的机制是涉及质子转移到羧基的WNA。预计这项工作将为合成优异的水氧化催化剂（WOCs）提供有意义的信息。
