N.N. Vorozhtsov Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia.
Molecules. 2023 Jan 23;28(3):1146. doi: 10.3390/molecules28031146.
X-ray diffraction analysis and IR spectroscopy were used to study the products of the interaction of vinyl cations CH and CH (Cat) (as salts of carborane anion CHBCl) with basic molecules of water, alcohols, and acetone that can crystallize from solutions in dichloromethane and CHF. Interaction with water, as content increased, proceeded via three-stages. (1) adduct Cat·OH forms in which HO binds (through the O atom) to the C=C bond of the cation with the same strength as seen in the binding to Na in Na(HO). (2) H is transferred from cation Cat·OH to a water molecule forming HO and alcohol molecules (L) having the CH=CHOH entity. The O- atom of alcohols is attached to the H atom of the C=C-H moiety of Cat thereby forming a very strong asymmetric H-bond, (C=)C-H⋅⋅⋅O. (3) Finally all vinyl cations are converted into alcohol molecule L and HO cations, yielding proton disolvates L-H-L with a symmetric very strong H-bond. When an acetone molecule (Ac) interacts with Cat, H is transferred to Ac giving rise to a reactive carbene and proton disolvate Ac-H-Ac. Thus, the alleged high reactivity of vinyl cations seems to be an exaggeration.
采用 X 射线衍射分析和红外光谱法研究了乙烯阳离子 CH 和 CH（Cat）（作为硼烷阴离子 CHBCl 的盐）与可从二氯甲烷和 CHF 溶液中结晶的水、醇和丙酮的碱性分子相互作用的产物。随着含量的增加，与水的相互作用经历了三个阶段。（1）形成加合物 Cat·OH，其中 HO 通过（O 原子）与阳离子的 C=C 键结合，其结合强度与在 Na（HO）中与 Na 的结合强度相同。（2）H 从阳离子 Cat·OH 转移到水分子，形成 HO 和醇分子（L），具有 CH=CHOH 实体。醇的 O 原子连接到 Cat 的 C=C-H 部分的 H 原子上，从而形成非常强的不对称氢键，（C=）C-H⋅⋅⋅O。（3）最后，所有的乙烯阳离子都转化为醇分子 L 和 HO 阳离子，生成质子溶剂化物 L-H-L，具有对称的非常强的氢键。当丙酮分子（Ac）与 Cat 相互作用时，H 转移到 Ac 上，产生反应性卡宾和质子溶剂化物 Ac-H-Ac。因此，所谓的乙烯阳离子的高反应性似乎有些夸张。
