College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471934, China.
Molecules. 2022 Jul 22;27(15):4690. doi: 10.3390/molecules27154690.
Dioxygen (O) is an environmentally benign and abundant oxidant whose utilization is of great interest in the design of bioinspired synthetic catalytic oxidation systems to reduce energy consumption. However, it is unfortunate that utilization of O is a significant challenge because of the thermodynamic stability of O in its triplet ground state. Nevertheless, nature is able to overcome the spin state barrier using enzymes, which contain transition metals with unpaired -electrons facilitating the activation of O by metal coordination. This inspires bioinorganic chemists to synthesize biomimetic small-molecule iron porphyrin complexes to carry out the O activation, wherein Fe-O species have been implicated as the key reactive intermediates. In recent years, a number of Fe-O intermediates have been synthesized by activating O at iron centers supported on porphyrin ligands. In this review, we focus on a few examples of these advances with emphasis in each case on the particular design of iron porphyrin complexes and particular reaction environments to stabilize and isolate metal-O intermediates in dioxygen activation, which will provide clues to elucidate structures of reactive intermediates and mechanistic insights in biological processes.
氧气（O）是一种环境友好且丰富的氧化剂，其利用对于设计仿生合成催化氧化体系以降低能耗具有重要意义。然而，不幸的是，由于 O 在三重基态下的热力学稳定性，其利用是一个重大挑战。尽管如此，自然界能够利用含有未配对电子的过渡金属的酶来克服自旋态障碍，从而促进 O 的活化，其中金属配位促进 O 的活化。这启发了生物无机化学家合成仿生小分子铁卟啉配合物来进行 O 活化，其中 Fe-O 物种被认为是关键的反应中间体。近年来，通过在卟啉配体上负载的铁中心活化 O，已经合成了许多 Fe-O 中间体。在这篇综述中，我们重点介绍了其中的几个例子，强调了每个例子中铁卟啉配合物的特定设计以及特定的反应环境，以稳定和分离氧气活化中的金属-O 中间体，这将为阐明生物过程中反应中间体的结构和机制提供线索。
