CoCH₃(PMe₃)₄ is known for a long time for its potential to activate less reactive C–H Bonds under extremely mild conditions by methane elimination. A spontaneous second C–H bond activation at the same center of cobalt complex is not expected. In contrast to previous investigations with certain aryl‐iminophosphane chelating ligands, in this work two consecutive metalation steps at the same complex center lead to a rare example of a cobalt metallabicycle. In the first step a C–H activation results in a five‐membered chelate ring, whereas the second ring is formed by an incomplete C–H activation which stops at a stable, rarely observed δ‐C–H agostic interaction. The results are supported by NMR spectroscopy, X ray structure analysis and density functional theory (DFT) calculations. Knowledge of such agostic interactions are essential in order to understand catalytic reaction paths and studies of such molecular structures of their ring sizes, bite angles and electronic properties have shown that these ligands allow sensitive control within the metal coordination sphere.

中文翻译：

---

δ-C-H固溶相互作用稳定的单个钴（I）配合物的自发双环金属化

CoCH ₃（PMe ₃）₄众所周知，在极温和的条件下，它具有通过消除甲烷来活化反应性较低的C–H键的潜力。预计不会在钴配合物的同一中心自发地发生第二个C–H键活化。与以前对某些芳基-亚氨基膦螯合配体的研究相反，在这项工作中，在同一复杂中心进行两个连续的金属化步骤导致了一个罕见的钴金属labalicycle实例。第一步，C–H活化产生一个五元螯合环，而第二个环由不完全的C–H活化形成，该活化以稳定的，很少观察到的δ–C–H异常相互作用停止。NMR光谱，X射线结构分析和密度泛函理论（DFT）计算为结果提供了支持。