Department of Chemistry, KTH Royal Institute of Technology, 10044 Stockholm, Sweden.
Dalton Trans. 2018 Oct 23;47(41):14381-14387. doi: 10.1039/c8dt01931b.
Resolving the questions, namely, the selection of Mn by nature to build the oxygen-evolving complex (OEC) and the presence of a cubic Mn3CaO4 structure in OEC coupled with an additional dangling Mn (Mn4) via μ-O atom are not only important to uncover the secret of water oxidation in nature, but also essential to achieve a blueprint for developing advanced water-oxidation catalysts for artificial photosynthesis. Based on the important experimental results reported so far in the literature and on our own findings, we propose a new hypothesis for the water oxidation mechanism in OEC. In this new hypothesis, we propose for the first time, a complete catalytic cycle involving a charge-rearrangement-induced MnVII-dioxo species on the dangling Mn4 during the S3 → S4 transition. Moreover, the O-O bond is formed within this MnVII-dioxo site, which is totally different from that discussed in other existing proposals.
解决这些问题，即自然界中 Mn 对构建氧析出复合物（OEC）的选择性，以及 OEC 中立方 Mn3CaO4 结构的存在和通过 μ-O 原子连接的额外悬空 Mn（Mn4），不仅对于揭示自然界中水氧化的奥秘至关重要，而且对于实现人工光合作用中先进水氧化催化剂的蓝图也至关重要。基于迄今为止文献中报道的重要实验结果和我们自己的发现，我们提出了 OEC 中水氧化机制的一个新假设。在这个新假设中，我们首次提出了一个完整的催化循环，其中包括在 S3 → S4 转变过程中悬空 Mn4 上电荷重排诱导的 MnVII-二氧基物种。此外，O-O 键在这个 MnVII-二氧基位点内形成，这与其他现有提案中讨论的完全不同。
