Reactive high-spin iron(IV)-oxo sites through dioxygen activation in a metal–organic framework
Kai-Peng Hou, Jonas Börgel, 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, 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
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 O 2 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 O 2 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 Mössbauer, Fe Kβ x-ray emission, and nuclear resonance vibrational spectroscopies. In the presence of O 2 , the framework is competent for catalytic oxygenation of cyclohexane and the stoichiometric conversion of ethane to ethanol.