Construction And Properties Of Supramolecular Functional Materials Based On Bispillar[5]arene

Supramolecular chemistry is defined as"beyond chemistry beyond molecules".It is an interdisciplinary discipline that forms complex and ordered supramolecular assembly systems with a variety of non-covalent bondw.Since 1987,supramolecular chemistry has received more and more attention and embedded research when Pedersen,Cram,and Lehn won the Nobel Prize in Chemistry.One of the most important aspects of supramolecular chemistry is macrocyclic chemistry.Among the important macrocyclic host known are crown ethers,cyclodextrin,calixarene,cucurbituril and pillararene.The emergence of each macrocyclic host has promoted the development of supramolecular chemistry,and the new macrocyclic host have been urgently explored.In 2008,the fifth-generation of macrocyclic host compound was reported by Japanese scientist T.Ogoshi for the first time,which named pillararenes.Pillar[n]arenes?n=5-10?are macrocyclic molecules bridged by para-methylene with repeating units of hydroquinone and its ethers.Compared with other macrocyclic host,pillararene have unique structural advantages,such as special symmetrical pillar architecture,electron-rich?-cavity with adjustable size,and desirable functional modification.In addition,pillararene have versatile host and guest performance,providing a place for self-assembly driving forces,such as multiple hydrogen bonding,C-H···?,?-?stacking,cations-?,metal coordination,Van der Waals and electrostatic interactions.Under the influence of various assembly driving interactions,a novel supramolecular functional materials besed on pillararene have been successfully constructed and applied them to life,environment,and medicine.Such as fluorescence sensing,molecular adsorption,inorganic Nano-materials,molecular machines,cell imaging,controlled drug release,and artificial transmembrane channels.In a short period of time,pillararene as a rising star in supramolecular chemistry attracted more and more researchers to explore and apply it to various fields.This thesis focus on the supramolecular functional materials based on pillar[5]arene in recent year and their research progress in stimulus response,ion recognition,molecular adsorption,catalysis,cell imaging,and controlled release of drugs.This paper is divided into four parts:In the first part,we summarized the research progress of supramolecular functional materials based on pillar[5]arene in recent years.In this section,we first summarize from the perspective of non-covalent bond interactions involved in supramolecular functional materials.This paper focuses on the construction of supramolecular functional materials based on pillar[5]arene through multiple hydrogen bonds,C-H···?,?-?stacking,metal-ligand coordination,and various non-covalent bonding interactions.Then from the application side,the supermolecular functional materials constructed based on pillar[5]arene are introduced in the field of stimulus response?pH,temperature,light,redox,mechanical?,identification and detection?cation,anion,small molecules?,applications in molecular adsorption separation,catalysis,cell imaging and drug release.In the second part,we designed and synthesized an azine-containing bispillar[5]arene as the host?BP5?,and the bi-pyridinium salt as the guest?G?,and successfully constructed a linear supramolecular pseudopolyrotaxane BP5·G.At high concentrations,supramolecular pseudopolyrotaxane gels are formed by intermolecular hydrogen bonding and?-?stacking.This gels showed a great reversible response to temperature,concentration,and showed irreversible stimulus response performance to organic acids,inorganic acids and competitive guests.In addition,the supramolecular pseudopolyrotaxane xerogel can be used as an adsorption material for adsorbing the dye molecule rhodamine B in an aqueous solution.The adsorption efficiency can reach98.4%.This work provides new ideas for the preparation of supramolecular functional materials based on bispillar[5]arene,and expands the application range of bispillar[5]arene.In the third part,we designed and synthesized a pyridylhydrazone functionalized bispillar[5]arene NBP5 as the host,and the tripod compound TG as the guest.A porous supramolecular polymer networks?NBP5-TG?was successfully constructed by non-covalent bond interactions such as host-guest interaction and intermolecular hydrogen bonding.Interestingly,NBP5-TG showed multiple responses to external stimuli,such as temperature,machinery,concentration,pH,and competitive objects.More importantly,the NBP5-TG xerogel can adsorb and separate methylene blue,crystal violet,methyl orange,orange I,Sudan red I and Sudan II organic dyes through complex intermolecular interactions.The adsorption rate of the gel to the dye is 83.15%-97.56%.In addition,NBP5-TG has good desorption performance as a good adsorbent.The organic solvent ethanol was washed at high temperature and showed good recyclability.The multi-stimulus reactivity and adsorption separation characteristics are based on the multiple interaction sites that we reasonably introduce NBP5-TG.Therefore,this is a convenient method for preparing multifunctional smart materials based on supramolecular polymer networks,and has potential application prospects in the adsorption of organic dyes.In the fourth part,we continue to use a pyridylhydrazone functionalization bispillar [5] arene NBP5 as the host and designa 2-hexadecylthiooxazolo[4,5-b]phenazine PA containing polyaromatic rings as a guest to construct a new supramolecular polymer NP.This supramolecular polymer gel has good bright yellow aggregation-induced emission?AIE?performance.Interestingly,the supramolecular polymer gels showed responsiveness to multiple external stimuli such as temperature,concentration,competitive guests,and mechanical forces.In addition,this supramolecular polymer gel can achieve high selectivity,ultra-sensitive identification and detection of iron ions through competition between the exo-wall?-?interactions and the cation-?interactions.The detection limit was 4.5nM.Finally,the film based on this supramolecular polymer gels can quickly detect Fe³⁺for rapid,efficient identification and detection.This experiment shows that supramolecular polymer gel NP has potential application prospects in the selective recognition of iron ions and fluorescent display materials.