Supramolecular Self-assembly And Properties Of 8-membered Cucurbital Ring And Spiral 14-membered Cucurbital Rin

In general,the method of synthesizing cucurbit[n]urils?Q[n]s?is to fully mix glycoluril and paraformaldehyde in cold 12 mol·L^-1·concentrated hydrochloric acid,and then heat to 110?to get various Q[n]s with different polymerization degree.We made some improvements on the basis of the previous synthesis method,and increased the quality of paraformaldehyde,that is,n?glycoluril?:n?paraformaldehyde?>2:1,the excess paraformaldehyde can make the reaction more sufficient and reduce polymers of glycoluril.Improved method is also tried for the separation of twisted tQ[13],tQ[14]and tQ[15],namely,the separation of twisted cucurbit[n]urils by changing the large plate thin layer chromatography to column chromatography and reducing the polarity of the eluent.Q[8]-based supramolecular self-assembly A and B can be prepared by evaporation from 8 mol?L^-1 hydrochloric acid solution and 80%formic acid solution,respectively.The outer surface interaction of Q[n]s and hydrogen bonding are the driving forces for the construction of supramolecular self-assembly A and B.X-ray powder diffraction characterization showed that the Q[8]precipitated in concentrated hydrochloric acid reaction solution during the synthesis process was consistent with the Q[8]crystal configuration obtained by natural crystallization in the 8 mol?L^-1 hydrochloric acid solution.Q[8]-baseda supramolecular self-assembly A has a certain pore structure,showing a certain adsorption capacity for a series of dyes and polycyclic compounds,and can change the optical properties of these adsorbents,especially the fluorescence properties.This makes it possible for the Q[8]-based supramolecular self-assembly adsorbed dyes to become fluorescent probes or sensors and the experimental results further confirm this assumption.For example,the assembly FG8@A formed by A adsorption pyrene?FG8?showed blue shift of emission wavelength and enhanced fluorescence intensity.The fluorescence intensities of FG12@a and FG15@a assembled by A adsorbed pyrene formaldehyde?FG12?and 8-hydroxyquinaldine?FG15?,respectively were enhanced to varying degrees.Response experiments on volatile organic compounds showed that FG8@A responded to formaldehyde,toluene and tetrachloromethane by fluorescence quenching,while FG14@A responded to formaldehyde by fluorescence enhancement.Q[8]-based supramolecular self-assembly B has honeycomb-like structure feature,and the channels composed of Q[8]molecules are filled with formic acid and solvent water molecules.Activated B?removal of formic acid and solvent water molecules in the pore passage?can form FG14@B by adsorbing danoyl chloride?FG14?,which emits a strong blue fluorescence at 470 nm;FG13@B formed by adsorbing phenanthrene?FG13?significantly reduced the purple fluorescence at 410 nm;FG4@B generated a new emission peak at 492nm on the basis that the fluorescence intensity remained almost unchanged at 378nm,and the fluorescence intensity was strong.In addition,FG8@B showed specific selectivity of acetone,can be used as a solid material for adsorption acetone gas.In this thesis,the interaction of the twistet cucurbit[14]uril?t Q[14]?and berberine hydrochloride?BE?and properties of the corresponding product were investigated:tQ[14]can make non-fluorescent BE produce strong fluorescence when the interaction ratio of tQ[14]:BE was 15:1.Nuclear magnetic resonance?NMR?techniques have shown that the berberine hydrochloride was located at portals of tQ[14].Moreover,the tQ[14]/BE interaction system showed specific selectivity for Fe³⁺ion and there was no interference from other metal ions.