济南大学Wonwoo Nam团队合成了一种具有前所未有的高O–O伸缩性和亲电反应性的单核非血红素铁（III）过氧化物复合物。相关研究成果于2021年9月16日发表在《美国化学会杂志》。

研究人员合成了一种单核非血红素铁（III）-过氧络合物 [Fe(III)(O2)(13-TMC)]+ (1)，并对其进行了光谱表征；电子顺磁共振、穆斯堡尔谱、X射线吸收谱、共振拉曼光谱和质谱的表征表明高自旋S=5/2 Fe（III）物种与O2单元结合。一个值得注意的观察结果是过氧配体在约1000 cm^–1处出现异常高的νO–O。就反应性而言，1在H原子提取（HAA）和O原子转移（OAT）反应中表现出亲电反应性。

在HAT反应中，9,10-二氢蒽氧化的动力学同位素效应（KIE）值为5.8。在OAT反应中，在p-X-取代硫茴香醚的氧化过程中，Hammett图中的ρ负值为0.61。另一个有趣的观察结果是1在苯甲醛衍生物氧化过程中的亲电反应性，如Hammett图中的负ρ值为0.77，KIE值为2.2。

该研究报告了第一个在氧化反应中具有异常高的νO–O值，和前所未有的亲电反应性的单核非血红素铁（III）-过氧络合物的例子。

附：英文原文

Title: A Mononuclear Non-heme Iron(III)–Peroxo Complex with an Unprecedented High O–O Stretch and Electrophilic Reactivity

Author: Wenjuan Zhu, Semin Jang, Jin Xiong, Roman Ezhov, Xiao-Xi Li, Taeyeon Kim, Mi Sook Seo, Yong-Min Lee, Yulia Pushkar, Ritimukta Sarangi, Yisong Guo, Wonwoo Nam

Issue&Volume: September 16, 2021

Abstract: A mononuclear non-heme iron(III)–peroxo complex, [Fe(III)(O2)(13-TMC)]+ (1), was synthesized and characterized spectroscopically; the characterization with electron paramagnetic resonance, Mssbauer, X-ray absorption, and resonance Raman spectroscopies and mass spectrometry supported a high-spin S = 5/2 Fe(III) species binding an O2 unit. A notable observation was an unusually high νO–O at ～1000 cm–1 for the peroxo ligand. With regard to reactivity, 1 showed electrophilic reactivity in H atom abstraction (HAA) and O atom transfer (OAT) reactions. In the HAT reaction, a kinetic isotope effect (KIE) value of 5.8 was obtained in the oxidation of 9,10-dihydroanthracene. In the OAT reaction, a negative ρ value of 0.61 in the Hammett plot was determined in the oxidation of p-X-substituted thioanisoles. Another interesting observation was the electrophilic reactivity of 1 in the oxidation of benzaldehyde derivatives, such as a negative ρ value of 0.77 in the Hammett plot and a KIE value of 2.2. To the best of our knowledge, the present study reports the first example of a mononuclear non-heme iron(III)–peroxo complex with an unusually high νO–O value and unprecedented electrophilic reactivity in oxidation reactions.

DOI: 10.1021/jacs.1c03358

Source: https://pubs.acs.org/doi/10.1021/jacs.1c03358