Schneider Joseph E, Zeng Shilin, Anferov Sophie W, Filatov Alexander S, Anderson John S
Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States.
J Am Chem Soc. 2024 Aug 28;146(34):23998-24008. doi: 10.1021/jacs.4c07335. Epub 2024 Aug 15.
High-valent cobalt oxides play a pivotal role in alternative energy technology as catalysts for water splitting and as cathodes in lithium-ion batteries. Despite this importance, the properties governing the stability of high-valent cobalt oxides and specifically possible oxygen evolution pathways are not clear. One root of this limited understanding is the scarcity of high-valent Co(IV)-containing model complexes; there are no reports of stable, well-defined complexes with multiple Co(IV) centers. Here, an oxidatively robust fluorinated ligand scaffold enables the isolation and crystallographic characterization of a Co(IV)-bis-μ-oxo complex. This complex is remarkably stable, in stark contrast with previously reported Co(IV) species that are highly reactive, which demonstrates that oxy-Co(IV) species are not necessarily unstable with respect to oxygen evolution. This example underscores a new design strategy for highly oxidizing transition-metal fragments and provides detailed data on a previously inaccessible chemical unit of relevance to O-O bond formation and oxygen evolution.
高价钴氧化物在替代能源技术中起着关键作用，可作为水分解的催化剂和锂离子电池的阴极。尽管具有这种重要性，但控制高价钴氧化物稳定性的性质，特别是可能的析氧途径尚不清楚。这种有限理解的一个根源是含高价Co(IV)的模型配合物稀缺；没有关于具有多个Co(IV)中心的稳定、明确配合物的报道。在这里，一种氧化稳定性强的氟化配体支架能够分离并通过晶体学表征一种Co(IV)-双-μ-氧代配合物。该配合物非常稳定，这与先前报道的高反应性Co(IV)物种形成鲜明对比，这表明氧合Co(IV)物种对于析氧不一定不稳定。这个例子强调了一种用于高氧化性过渡金属片段的新设计策略，并提供了与O-O键形成和析氧相关的先前无法获得的化学单元的详细数据。
