Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, USA.
Inorg Chem. 2010 Apr 19;49(8):3618-28. doi: 10.1021/ic901891n.
Dioxygen (O(2)) activation by iron enzymes is responsible for many metabolically important transformations in biology. Often a high-valent iron oxo oxidant is proposed to form upon O(2) activation at a mononuclear nonheme iron center, presumably via intervening iron superoxo and iron peroxo species. While iron(IV) oxo intermediates have been trapped and characterized in enzymes and models, less is known of the putative iron(III) superoxo species. Utilizing a synthetic model for the 2-oxoglutarate-dependent monoiron enzymes, [(Tp(iPr2))Fe(II)(O(2)CC(O)CH(3))], we have obtained indirect evidence for the formation of the putative iron(III) superoxo species, which can undergo one-electron reduction, hydrogen-atom transfer, or conversion to an iron(IV) oxo species, depending on the reaction conditions. These results demonstrate the various roles that the iron(III) superoxo species can play in the course of O(2) activation at a nonheme iron center.
氧分子（O(2)）的活化是许多生物学中重要代谢转化的基础。通常，在单核非血红素铁中心的氧分子活化过程中，会形成高价态铁氧氧化剂，可能是通过中间的铁过氧和铁过氧物种。虽然已经在酶和模型中捕获和表征了铁(IV) 氧中间体，但对于假定的铁(III) 过氧物种知之甚少。利用 2- 氧代戊二酸依赖性单铁酶的合成模型 [(Tp(iPr2))Fe(II)(O(2)CC(O)CH(3))]，我们已经获得了形成假定的铁(III) 过氧物种的间接证据，该物种可以根据反应条件进行单电子还原、氢原子转移或转化为铁(IV) 氧物种。这些结果表明了铁(III) 过氧物种在非血红素铁中心的氧分子活化过程中可以发挥的各种作用。
