Department of Chemistry, University of California-Irvine, Irvine, CA 92697, USA.
Molecules. 2023 Jun 14;28(12):4755. doi: 10.3390/molecules28124755.
Non-heme Fe monooxygenases activate C-H bonds using intermediates with high-spin Fe-oxido centers. To mimic these sites, a new tripodal ligand [pop] was prepared that contains three phosphoryl amido groups that are capable of stabilizing metal centers in high oxidation states. The ligand was used to generate [Fepop(O)], a new Fe-oxido complex with an = 2 spin ground state. Spectroscopic measurements, which included low-temperature absorption and electron paramagnetic resonance spectroscopy, supported the assignment of a high-spin Fe center. The complex showed reactivity with benzyl alcohol as the external substrate but not with related compounds (e.g., ethyl benzene and benzyl methyl ether), suggesting the possibility that hydrogen bonding interaction(s) between the substrate and [Fepop(O)] was necessary for reactivity. These results exemplify the potential role of the secondary coordination sphere in metal-mediated processes.
非血红素 Fe 单加氧酶使用具有高自旋 Fe-氧中心的中间产物来激活 C-H 键。为了模拟这些位点，合成了一种新的三脚架配体 [pop]，它含有三个膦酰胺基，能够稳定高氧化态的金属中心。该配体用于生成 [Fepop(O)]，这是一种具有 = 2 自旋基态的新型 Fe-氧配合物。包括低温吸收和电子顺磁共振光谱在内的光谱测量结果支持高自旋 Fe 中心的分配。该配合物显示出与苄醇作为外部底物的反应活性，但与相关化合物（例如乙基苯和苄基甲基醚）没有反应活性，这表明底物与 [Fepop(O)] 之间氢键相互作用可能是反应活性所必需的。这些结果例证了次级配位球在金属介导过程中的潜在作用。
