The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration...The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration calorimetry(ITC) and X-ray crystallography. The data indicates that the Q[5]@4-AP complex exhibits exo binding, which is not observed in the other four host-guest complexes. Furthermore,X-ray crystallography clearly reveals how the Q[n]s bind with 4-AP to form complexes, for example Q[5]forms an outer-surface complex, whilst Q[6], TMe Q[6] and Q[7] formed 1:1 host and guest type complexes, and Q[8] formed a stable 1:2 ternary complex due to its large cavity, which can accommodate two 4-AP molecules.展开更多
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...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.展开更多
基金supported by the Innovation Program for Highlevel Talents of Guizhou Province (No. 2016-5657)the University of Hull for support。
文摘The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration calorimetry(ITC) and X-ray crystallography. The data indicates that the Q[5]@4-AP complex exhibits exo binding, which is not observed in the other four host-guest complexes. Furthermore,X-ray crystallography clearly reveals how the Q[n]s bind with 4-AP to form complexes, for example Q[5]forms an outer-surface complex, whilst Q[6], TMe Q[6] and Q[7] formed 1:1 host and guest type complexes, and Q[8] formed a stable 1:2 ternary complex due to its large cavity, which can accommodate two 4-AP molecules.
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)+2 种基金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)。
文摘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.
