德国杜伊斯堡-埃森大学Schulz, Stephan团队报道了室温稳定的反芳香环戊二烯基阳离子盐的结构表征和反应性。相关研究成果于2024年1月15日发表在国际顶尖学术期刊《自然—化学》。

环戊二烯基（Cp）阳离子的单线态被认为是反芳香体系的真正原型。不幸的是，它们的高固有反应性抑制了它们作为盐在固态中的分离，并且受控反应也很少。

该文介绍了室温稳定的Cp阳离子盐 [Cp(C₆F₅)₅]⁺[Sb₃F₁₆]^-的合成和固态结构。尽管根据量子化学计算， [Cp(C₆F₅)₅]⁺阳离子的芳香族三重态在气相中在能量上是有利的，但晶格中[Sb₃F₁₆]或C₆F₆对阳离子的配位稳定了固态中存在的反芳香单线态。

 [Cp(C₆F₅)₅]⁺阳离子计算的氢化物和氟化物离子亲和力，高于全氟三丁基阳离子[C(C₆F₅)₃]⁺的计算的氢和氟化物离子亲和性。还介绍了 [Cp(C₆F₅)₅]⁺[Sb₃F₁₆]^-与CO的反应，其可能产生相应的羰基络合物，以及自由基 Cp(C₆F₅)₅与选定的模型底物(Cp₂Fe, (Ph₃C)₂和Cp*Al)的反应。

附：英文原文

Title: Structural characterization and reactivity of a room-temperature-stable, antiaromatic cyclopentadienyl cation salt

Author: Schulte, Yannick, Wlper, Christoph, Rupf, Susanne M., Malischewski, Moritz, SantaLucia, Daniel J., Neese, Frank, Haberhauer, Gebhard, Schulz, Stephan

Issue&Volume: 2024-01-15

Abstract: The singlet states of cyclopentadienyl (Cp) cations are considered as true prototypes of an antiaromatic system. Unfortunately, their high intrinsic reactivity inhibited their isolation in the solid state as a salt, and controlled reactions are also scarce. Here we present the synthesis and solid state structure of the room-temperature-stable Cp cation salt [Cp(C6F5)5]+[Sb3F16]. Although the aromatic triplet state of the [Cp(C6F5)5]+ cation is energetically favoured in the gas phase according to quantum chemical calculations, coordination of the cation by either [Sb3F16] or C6F6 in the crystal lattice stabilizes the antiaromatic singlet state, which is present in the solid state. The calculated hydride and fluoride ion affinities of the [Cp(C6F5)5]+ cation are higher than those of the perfluorinated tritylium cation [C(C6F5)3]+. Reactions of [Cp(C6F5)5]+[Sb3F16] with CO, which probably yields the corresponding carbonyl complex, and of radical Cp(C6F5)5 with selected model substrates (Cp2Fe, (Ph3C)2 and Cp*Al) are also presented.

DOI: 10.1038/s41557-023-01417-5

Source: https://www.nature.com/articles/s41557-023-01417-5