Oxygenation of a tricopper(I) cyclophanate (1) affords reactive transients competent for C–H bond activation and O atom transfer to various substrates (including toluene, dihydroanthracene, and ethylmethylsulfide) based on ¹H NMR, gas chromatography/mass spectrometry (MS), and electrospray ionization (ESI)/MS data. Low product yields (<1%) are determined for C–H activation substrates (e.g, toluene, ethylbenzene), which we attribute to competitive ligand oxidation. The combined stopped-flow UV/visible, electron paramagnetic resonance, ESI/MS, ¹H NMR, and density functional theory (DFT) results for reaction of 1 with O₂ are consistent with transient peroxo- and di(oxo)-bridged intermediates. DFT calculations elucidate a concerted proton-coupled electron transfer from toluene to the di(μ-oxo) intermediate and subsequent radical rebound as the C–H activation mechanism. Our results support a multicopper oxidase-like mechanism for O₂ activation by 1, traversing species similar to the coplanar Cu₃O₂ unit in the peroxy and native intermediates.

中文翻译：

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具有O原子转移，CH键活化和多个O ₂活化步骤的Tricopper（I）复合物

一个tricopper的氧合（I）cyclophanate（1）得到的反应性瞬变胜任C-H键活化和O原子转移到各种基材（包括甲苯，二氢蒽，和ethylmethylsulfide）基于¹ H NMR，气相色谱/质谱（MS ）和电喷雾电离（ESI）/ MS数据。确定了C–H活化底物（例如甲苯，乙苯）的低产品收率（<1％），这归因于竞争性配体氧化。1与O ₂反应的合成停止流UV /可见光，电子顺磁共振，ESI / MS，¹ H NMR和密度泛函理论（DFT）结果与瞬时过氧桥和二氧桥桥接的中间体一致。DFT计算阐明了质子耦合电子从甲苯向二（μ-氧代）中间体的协调转移以及随后的作为CH活化机理的自由基反弹。我们的研究结果支持了一种通过1激活O ₂的多铜氧化酶样机制，遍历过氧化物和天然中间体中与共面Cu ₃ O ₂单元相似的物种。