Recognition of glycine by cucurbit[5]uril and cucurbit[6]uril:A comparative study of exo-and endo-binding

作     者：Peihui Shan Ruilian Lin Ming Liu Zhu Tao Xin Xiao Jingxin Liu Peihui Shan;Ruilian Lin;Ming Liu;Zhu Tao;Xin Xiao;Jingxin Liu

作者机构：Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province.Guizhou UniversityGuiyang 550025China College of Chemistry and Chemical EngineeringAnhui University of TechnologyMaanshan 243002China 

出 版 物：《Chinese Chemical Letters》 (中国化学快报（英文版）)

年 卷 期：2021年第32卷第7期

页      面：2301-2304页

核心收录：

学科分类：07[理学] 070303[理学-有机化学] 0703[理学-化学] 

基　　金：supported by the National Natural Science Foundation of China(No.21861011) the Innovation Program for High-level Talents of Guizhou Province(No.2016-5657) the Major Program for Creative Research Groups of Guizhou Provincial Education Department(2017-028) the Science and Technology Fund of Guizhou Province(No.2018-5781) the Natural Science Foundation of Anhui Province of China(Nos.1808085MB43,2008085MB36)。 

主　　题：Cucurbituril endo-Binding exo-Binding Selective recognition Supramolecular assembly 

摘      要：Recognition features of glycine(Gly)with cucurbit[5]uril(Q[5])and cucurbit[6]uril(Q[6])both in aqueous solution and solid state were investigated by 1 H NMR spectroscopy and X-ray crystallography.1 H NMR data indicate that the Gly is located outside of the portals of the Q[5],exhibiting exo binding with the Q[5].In the case of the Q[6],the Gly shows endo binding or a dual binding mode(endo and exo binding)with the host,which depends on the amount of the host in the aqueous solution.X-ray crystallography clearly display that the Gly forms 2:1 exclusion complex with the Q[5],and 2:1 inclusion complex with the Q[6].Interestingly,hydrogen bondings between the encapsulated Gly molecules in the Q[6]were observed.