Gas‐Phase Characterization of Hypervalent Carbon Compounds Bearing 7‐6‐7‐Ring Skeleton: Penta‐/Tetra‐Coordinate Isomers
Gas‐Phase Characterization of Hypervalent Carbon Compounds Bearing 7‐6‐7‐Ring Skeleton: Penta‐/Tetra‐Coordinate Isomers
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带有 7-6-7 环骨架的高价碳化合物的气相表征：五配位/四配位异构体
DOI：
10.1002/chem.202203163
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Inokuchi Yoshiya
中科院分区：
文献类型：
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作者：
Muramatsu Satoru;Ohshimo Keijiro;Shi Yuan;Kida Motoki;Shang Rong;Yamamoto Yohsuke;Misaizu Fuminori;Inokuchi Yoshiya
在这项研究中，我们提供了明确的电子和几何结构的表征最近报道的高价五配位碳化合物通过使用气相表征技术：光解离光谱（PDS）和离子迁移-质谱（IM-MS）。特别是对于具有适度供电子配体的化合物，带有对甲硫基苯基取代基，四配位异构体和五配位异构体的共存得到证实，与溶液表征一致。它与单晶中唯一的四配位形式（具有中心碳原子的正常价态）形成鲜明对比。这表明非极性环境使五配位结构在化学上最稳定。四配位和五配位结构之间的这种微妙差异取决于环境，这密切反映了在中性溶剂或气相反应中发现的SN 2反应的较低活化势垒。
In this study, we afford explicit characterizations of the electronic and geometrical structures of recently reported hypervalent penta‐coordinate carbon compounds by using gas‐phase characterization techniques: photodissociation spectroscopy (PDS) and ion mobility‐mass spectrometry (IM–MS). In particular for a compound with moderately electron‐donating ligands, bearingp‐methylthiophenyl substituents, the coexistence of tetra‐ and penta‐coordinate isomers is confirmed, consistent with solution characterizations. It is in sharp contrast to the exclusive tetra‐coordinate form (with normal valence of the central carbon atom) in the single crystal. This suggests that a non‐polar environment makes the penta‐coordinate structure thermodynamically most stable. This delicate difference between the tetra‐ and penta‐coordinate structures, which depends on the environment, is a close reflection of the lower activation barrier of the SN2 reaction found in neutral solvent or gas‐phase reactions.