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.
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)。
