Stoyanov Evgenii S, Hoffmann Stephan P, Kim Kee-Chan, Tham Fook S, Reed Christopher A
Boreskov Institute of Catalysis, Prospekt Lavrentieva, 5, Novosibirsk 630090, Russia.
J Am Chem Soc. 2005 Jun 1;127(21):7664-5. doi: 10.1021/ja050401k.
Infrared, X-ray structural, 1H NMR, and computational evidence for pi-solvation of H3O+ by benzene molecules is presented. A salt with a discrete [H3O.3benzene]+ cation can be isolated using a very weakly interacting carborane counterion, CHB11Cl11-. pi-Arene solvation of H3O+ explains the solubility of this salt in benzene solution. Similar results are indicated for the "Zundel-type" H5O2+ ion. These findings suggest structures for the active protonating species when strong acids are used as catalysts in arene solvents containing trace water. They are also relevant to structures that may be present in biological proton transport.
本文给出了苯分子对H₃O⁺进行π-溶剂化作用的红外、X射线结构、¹H NMR以及计算证据。使用一种相互作用非常弱的碳硼烷抗衡离子CHB₁₁Cl₁₁⁻，可以分离出具有离散[H₃O·3苯]⁺阳离子的盐。H₃O⁺的π-芳烃溶剂化解释了该盐在苯溶液中的溶解性。对于“津德尔型”H₅O₂⁺离子也有类似结果。这些发现表明了在含有痕量水的芳烃溶剂中使用强酸作为催化剂时活性质子化物种的结构。它们也与生物质子传输中可能存在的结构相关。
