美国加州大学Jeffrey R. Long团队报道了在金属有机框架中通过双氧活化的反应性高自旋铁(IV)-氧代位点。相关研究成果发表在2023年11月3日出版的《科学》。

在自然界中，非血红素铁酶利用双氧生成高自旋铁（IV）=O物种，用于各种氧化反应。尽管合成化学家长期以来一直试图模拟这种反应性，但像酶一样激活O₂以形成高自旋铁（IV）=O物种仍然是一个未实现的目标。

该文中，研究人员报道了一种以铁（II）位点为特征的金属-有机框架，其局部结构与α-酮戊二酸依赖性双加氧酶相似。该框架在低温下与O₂反应形成高自旋铁（IV）=O物种，使用原位漫反射红外傅立叶变换、原位和可变场Mssbauer、Fe-K_β X射线发射和核共振振动光谱对其进行表征。在O₂存在的情况下，该框架能够催化环己烷的氧化和乙烷向乙醇的化学计量转化。

附：英文原文

Title: Reactive high-spin iron(IV)-oxo sites through dioxygen activation in a metal–organic framework

Author: Kaipeng Hou, Jonas Brgel, Henry Z. H. Jiang, Daniel J. SantaLucia, Hyunchul Kwon, Hao Zhuang, Khetpakorn Chakarawet, Rachel C. Rohde, Jordan W. Taylor, Chaochao Dun, Maria V. Paley, Ari B. Turkiewicz, Jesse G. Park, Haiyan Mao, Ziting Zhu, E. Ercan Alp, Jiyong Zhao, Michael Y. Hu, Barbara Lavina, Sergey Peredkov, Xudong Lv, Julia Oktawiec, Katie R. Meihaus, Dimitrios A. Pantazis, Marco Vandone, Valentina Colombo, Eckhard Bill, Jeffrey J. Urban, R. David Britt, Fernande Grandjean, Gary J. Long, Serena DeBeer, Frank Neese, Jeffrey A. Reimer, Jeffrey R. Long

Issue&Volume: 2023-11-03

Abstract: In nature, nonheme iron enzymes use dioxygen to generate high-spin iron(IV)=O species for a variety of oxygenation reactions. Although synthetic chemists have long sought to mimic this reactivity, the enzyme-like activation of O2 to form high-spin iron(IV) = O species remains an unrealized goal. Here, we report a metal–organic framework featuring iron(II) sites with a local structure similar to that in α-ketoglutarate-dependent dioxygenases. The framework reacts with O2 at low temperatures to form high-spin iron(IV) = O species that are characterized using in situ diffuse reflectance infrared Fourier transform, in situ and variable-field Mssbauer, Fe Kβ x-ray emission, and nuclear resonance vibrational spectroscopies. In the presence of O2, the framework is competent for catalytic oxygenation of cyclohexane and the stoichiometric conversion of ethane to ethanol.

DOI: add7417

Source: https://www.science.org/doi/10.1126/science.add7417