Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea.
Department of Emerging Materials Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.
Inorg Chem. 2022 Mar 14;61(10):4292-4301. doi: 10.1021/acs.inorgchem.1c03104. Epub 2022 Feb 28.
High-valent transition metal-hydroxide complexes have been proposed as essential intermediates in biological and synthetic catalytic reactions. In this work, we report the single-crystal X-ray structure and spectroscopic characteristics of a mononuclear nonporphyrinic Mn-(OH) complex, [Mn(Me-TPADP)(OH)(OCHCH)] (), using various physicochemical methods. Likewise, [Mn(Me-TPADP)(OH)(OCHCF)] (), which is thermally stable at room temperature, was also synthesized and characterized spectroscopically. The Mn-(OH) adducts are capable of performing oxidation reactions with external organic substrates such as C-H bond activation, sulfoxidation, and epoxidation. Kinetic studies, involving the Hammett correlation and kinetic isotope effect, and product analyses indicate that and exhibit electrophilic oxidative reactivity toward hydrocarbons. Density functional theory calculations support the assigned electronic structure and show that direct C-H bond activation of the Mn-(OH) species is indeed possible.
高价过渡金属-氢氧化物配合物被认为是生物和合成催化反应中的重要中间体。在这项工作中，我们使用各种物理化学方法报道了单核非卟啉 Mn-(OH)配合物Mn(Me-TPADP)(OH)(OCHCH)的单晶 X 射线结构和光谱特性。同样，我们还合成并通过光谱法表征了在室温下热稳定的Mn(Me-TPADP)(OH)(OCHCF)。Mn-(OH)加合物能够进行氧化反应，与外部有机底物如 C-H 键活化、磺氧化和环氧化反应。动力学研究，包括哈米特相关性和动力学同位素效应以及产物分析表明，和对烃类具有亲电氧化反应性。密度泛函理论计算支持所分配的电子结构，并表明 Mn-(OH)物种的直接 C-H 键活化确实是可能的。
