八元瓜环与二(2-亚甲基-1,2,3,4-四氢异喹啉)的自组装模式

以用1,2,3,4-四氢喹啉和二溴乙烷合成的二(2-亚甲基-1,2,3,4-四氢异喹啉)的溴化氢酸盐为客体, 八元瓜环为主体, 利用1H NMR技术, 单晶X射线衍射方法以及理论计算等方法, 考察了两者的自组装模式. 1H NMR分析结果表明, 在溶液状态条件下, 不仅每一个八元瓜环分子同时与两个客体分子的芳环部分相互作用, 而且每一个客体分子两端的芳环部分同时与两个八元瓜环分子相互作用, 从而形成一维的自组装超分子链; 而在固体状态下, 每一个八元瓜环也可同时包结两个客体的芳环部分而形成三元的自组装结构, 但八元瓜环包结两个客体形成一独立的三元自组装结构. 利用晶体结构建立模型的计算结果说明, 模拟溶液状态比固体状态条件下的主客体包结更有利于体系能量的降低, 与主客体在溶液中1H NMR实验结果相符.

Self-assembly Modes of Cucurbit[8]uril with Bis(1,2,3,4- tetrahydroisoquinoline-2-ylmethyl)

Bis(1,2,3,4-tetrahydroisoquinoline-2-ylmethyl) HBr salt(K2) guest has been synthesized from 1,2,3,4-tetrahydroisoquinoline and ethylenedibromide.The self-assembly interaction models of cucurbit8]uril(Q8]) with this synthetic guest have been investigated by using 1H NMR technique,single crystal X-ray diffraction determination and theoretic calculation method.The 1H NMR spectral analysis established a basic interaction model in which a self-assembly supramolecular pseudorotaxane with a host:guest ratio of 1:1 forms,in which each host selectively includes the aromatic moieties of two guests and both of the aromatic moieties of each guest were included in the two cavities of two hosts.However,the single crystal structure of the Q8]-K2 inclusion complex showed that a self-assembly pseudorotaxane with a host:guest ratio of 1:2 forms,in which each host also selectively includes the two aromatic moieties of two guests.The calculation results based on the crystal structure data showed that,compared to the free guest and host,the inclusion complex in both solution and solid state appeared to favor in energy.