Gupta Sikha, Arora Pragya, Aghaei Zahra, Singh Baghendra, Jackson Timothy A, Draksharapu Apparao
Southern Laboratories-208A, Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Department of Chemistry and Center for Environmentally Beneficial Catalysis, The University of Kansas, Lawrence, Kansas 66045, United States.
J Am Chem Soc. 2025 Jan 8;147(1):619-626. doi: 10.1021/jacs.4c12523. Epub 2024 Dec 17.
Understanding the basic structure of the oxygen-evolving complex (OEC) in photosystem II (PS-II) and the water oxidation mechanism can aid in the discovery of more efficient and sustainable catalysts for water oxidation. In this context, we present evidence of the formation of a [(TPA)Mn(O)(μ-O)Ce(NO)] () complex (TPA = tris(pyridyl-2-methyl)amine) by adding aqueous ceric ammonium nitrate to an acetonitrile solution of the [(TPA)Mn] () complex. This unique intermediate () was analyzed by using various spectroscopic techniques and electrospray ionization mass spectrometry. Remarkably, closely mimics the structure of Mn(O)(μ-O)Ca(OH) proposed in the OEC of PS-II. Notably, reacts effectively with ferrocene derivatives, indicating that redox-active Ce binding enhances the electron transfer efficiency. Additionally, demonstrated the ability to perform oxygen atom transfer and hydrogen atom abstraction reactions. The discovery of this reactive [(TPA)Mn(O)(μ-O)Ce(NO)] species provides exciting opportunities for investigating the structure of the Mn(O)(μ-O)Ca(OH) unit in the OEC.
了解光系统II（PS-II）中析氧复合物（OEC）的基本结构以及水氧化机制，有助于发现更高效、可持续的水氧化催化剂。在此背景下，我们展示了通过向[(TPA)Mn]（）配合物的乙腈溶液中加入硝酸铈铵水溶液形成[(TPA)Mn(O)(μ-O)Ce(NO)]（）配合物（TPA = 三（吡啶-2-甲基）胺）的证据。通过使用各种光谱技术和电喷雾电离质谱对这种独特的中间体（）进行了分析。值得注意的是，其紧密模拟了PS-II的OEC中提出的Mn(O)(μ-O)Ca(OH)结构。值得注意的是，它与二茂铁衍生物有效反应，表明氧化还原活性Ce结合提高了电子转移效率。此外，它还展示了进行氧原子转移和氢原子提取反应的能力。这种活性[(TPA)Mn(O)(μ-O)Ce(NO)]物种的发现为研究OEC中Mn(O)(μ-O)Ca(OH)单元的结构提供了令人兴奋的机会。
