Coustruction And Application Of Novel Supramolecular Aie Systems Based On Pillar[5]arenes

Aggregation-induced emission?AIE?was first discovered and reported by Tang Benzhong in 2001.The discovery of AIE provides a new research direction for the field of fluorescent materials.Compounds with this property can be used as a good fluorescent probe and have received more and more attention.Therefore,developing a new AIE group is an attractive topic.A novel macrocyclic host molecule pillar[5]arene after the crown ether,cyclodextrin,calixarene,and cucurbituril was first reported by Ogoshi in 2008.Due to its uniform pillar shape,easy preparation and easy functionalization,rigid structure and electron-rich cavities,it imparts unique host-guest complexation properties to pillar[5]arenes.They have received more and more attention in various fields such as drug release,cell imaging,separation and adsorption,phase transfer catalysis,fluorescence sensing and so on.At the same time,pillar[5]arenes provides a good platform for the development of AIE groups.It is worth mentioning that,as of now,the literature on the use of pillar[5]arenes as fluorescent luminescent groups has rarely been reported.Therefore,we applied pillar[5]arenes to AIE,constructed different AIE systems through the assembly of functionalized pillar[5]arenes,and studied their fluorescence sensing properties for different ions.Through research,we found that the constructed AIE system can achieve high sensitivity,uniquely identify anions and cations in aqueous solution,and has a good application prospect for cation adsorption.This paper is divided into four parts:Part One,We reviewed the related reviews and literature and introduced the the self-assembly,application of pillar[n]arenes and pillar[n]arenes with aggregation induced emission effects.The pillar[n]arenes with aggregation induced emission effects are highlighted,and the self-assembly of pillar[n]arenes is summarized in the fields of fluorescence sensing,drug release,cell imaging,separation and adsorption,phase transfer catalysis,photosensors,etc.Application and prospects.Emphasis is placed on the application of pillar[n]arene in the field of fluorescence sensing,including ion sensing,molecular sensing,bioimaging,and supramolecular aggregates.Part Two,We obtained a novel tri-pillar[5]arene-based supramolecular organic gelator JP5 by condensing acylhydrazine functionalized pillar[5]arene and benzene tricarboxylic acid chloride in dichloromethane.Through experiments we found that the stable supramolecular polymer JP5G was obtained within 0.5 minutes by the self-assembly of gelator JP5 in cyclohexanol via C-H…?,?…?stacks,vdW forces and hydrogen bonding interactions with strong blue aggregate induced emission effects.the JP5G presented special selective and high sensing properties for Hg²⁺,and othe cations didn't interfer in the sensing process.In addition,JP5G xerogel could effectively remove Hg²⁺from water.What's more,a thin film based on the organogel?JP5G?could also act as a convenient test kit for the detection of Hg²⁺.Part Three,We condensed the benzenedialdehyde and acylhydrazine functionalized pillar[5]arene to obtain a novel dihydrazone-linked bispillar[5]arene compound QS.It was found through research that the pillar[5]arene could act as a novel AIE?aggregation-induced emission?-based groups.Compound QS has no fluorescence in DMSO solution.However,QS could self-assemble in the DMSO-H₂O binary solution via intermolecular hydrogen bonding,?-?stacking and other interactions to emit strong yellow-green fluorescence accompanied by high fluorescence quantum yield.Meanwhile,bispillar[5]arene compound QS could act as a fluorescence sensor to detect Hg²⁺in water with high sensitivity and specificity.In addition,compound QS can be used as a new type of material to separate Hg²⁺in water.Moreover,QS-based thin film was prepared,which could act as fluorescent display material with potential practical applications.Part Four,We designed and synthesized a novel hydrazone-linked long alkyl chain functionalized pillar[5]arene PZ.in which,the long alkyl chain could provide intermolecular forces,pillar[5]arene act as a fluorescent group,and hydrazone was introduced into the molecule act as recognition site.Interestingly,the compound PZ could self-assemble into stable supramolecular organogel?OPZ?in cyclohexanol by intermolecular hydrogen bonding,?-?stacking,host-guest interaction,etc.and show blue aggregation-induced emission?AIE?.Simultaneously,the organogel OPZ could fluorescence sense iodide ion?I^-?with high selectivity and sensitivity.What's more,other anions didn't interfere in the sensing process.Otherwise,the supramolecular film prepared based on the supramolecular organic gel can be used as a fluorescent security detection tool.