两种部分甲基取代瓜环配合物的晶体结构(英文)

Crystal Structures of Two Partially Methyl-Substituted Cucurbit[n]urils

本文报道了2种新的部分甲基取代瓜环配合物的晶体结构,利用X-射线单晶衍射技术表征了2种配合物的结构,在CdCl2溶液中,1,2,4,5-八甲基六元瓜环选择性的包结客体分子1,2-(2,2′-bisbenzimidazolyl)ethanedichloride,形成2∶1的哑铃型主客体包结配合物;而1,2,4-六甲基五元瓜环(HMeQ[5])与钠离子配位形成包结一个水分子的"分子胶囊","分子胶囊"之间通过氢键自组装形成一维的超分子长链。

Two partial methyl-substituted cucurbit[n]urils were characterized by single-crystal X-ray diffractions. A new methyl-substituted cucurbituril, 1,2,4,5-octamethylcucurbit[6]uril （OMeQ[6]） was separated by the formation of the inclusion complexes of OMeQ[6] with 1,2-（2,2′-bisbenzimidazolyl）ethane dichloride （SBE） in the presence of CdCl2, and a 1,2,4-hexamethylcucurbit[5]uril （HMeQ[5]） coordination to sodium ion was also obtained. In the crystal structure of compound {（SBE@2OMeQ[6]）^2＋[Cd2（ μ-Cl）2（Cl2）2（H2O）2]^2-} （1）, the OMeQ[6] host selectively included the benzimidazolyl moiety of the guest SBE through the hydrophobic cavity interaction and the ion- dipole interaction of the cation N＋ with the carbonyl oxygens of the host, and formed a dumbbell shape host-guest inclusion complex with a ratio of 2∶1. In the crystal structure of the complex {[Na（H2O）HMeQ[5]]^＋（NO3）^-5H2O} （2）, a molecular capsule included one water molecule was formed, and the capsules assembled one-dimensional supramolecular chain through the hydrogen bonding.