Construction And Properties Of Supramolecular Materials Based On Quinoline Functionalized Pillar[5]arene

Supramolecular materials are new material constructed by self-assemble using non-covalent interactions between molecules?van der Waals forces,hydrogen bonds,electron donor-acceptor interactions,hydrophilic/hydrophobic interactions,ionic interactions and so on?.Compared with traditional materials,supramolecular materials have the advantages of reversibility,adaptability,reactivity,self-healing and degradability.Therefore,a host of researchers are devoted to the research of supramolecular materials.Macrocyclic compounds,such as crown ether,cyclodextrins,calixarenes,cucurbiturils and pillararenes,are often selected as important and representative host molecules for the construction of supramolecular materials because of their excellent selectivity and stimuli-response performance.In 2008,Japanese professor Ogoshi synthesized and reported the fifth generation macrocyclic host,pillar[n]arenes.In the past ten years,pillar[n]arene derivatives have been considered as the ideal building blocks for building various supramolecular systems.In this paper,we first study and summarize the recent construction of supramolecular materials based on functionalized pillar[n]arenes and their applications in different fields.Secondly,our ongoing interest in the functionalized pillar[n]arenes,construction of supramolecular materials and their applications in molecular,ion detection and multi-stimuli responsive materials,herein,we further explored the construction of different supramolecular materials based on functionalized pillar[n]arenes and their performance in ultrasensitive detection,efficient removal of important ions in water,and multi-stimuli responsive materials.This paper includes four parts:In the first part,we have consulted a large number of literatures and reviews on pillar[n]arenes and summarized the types of supramolecular materials based on functionalized pillar[n]arenes in recent years,for instance,supramolecular polymers,rotaxanes or pseudorotaxanes,vesicles or micelles,supramolecular organic frameworks or supramolecular polymer networks and so on,and application progress of these supramolecular materials that have been successfully constructed in the fields of catalysis,light capture,drug release,cell imaging,fluorescence sensing,ion and molecular adsorption and separation ect.Through the above learning,summarizing and combined with the research direction of our research group,we put forward my own research topic.In the second part,we first designed and synthesized two functionalized pillar[n]arenes.Firstly,the 8-hydroxyquinoline group was reasonably introduced into the pillar[5]arene to obtain a new host compound QP5.Secondly,bromohexyl modified pillar[5]arene P5C6 were synthesized as guest molecules.Two functionalized pillar[5]arene QP5 and P5C6 successfully constructed the supramolecular organic framework gel PQPA in cyclohexanol solution or mixed solution of DMSO/H₂O?8:2,v/v?through the external wall?···?interaction and the host-guest interaction.The gel PQPA has strong aggregation induced emission enhancement?AIEE?phenomenon.At the same time,the gel PQPA showed the ability of ultrasensitive detection and efficient removal Fe³⁺from water.When Fe³⁺is added to gel PQPA,supramolecular metal organic framework gel PQPA-Fe without fluorescence emission can be constructed.The gel PQPA-Fe can ultrasensitively detect F^-in water.In addition,the gel PQPA can detect Fe³⁺in the actual sample?Yellow River water?.Finally,gel films based on PQPA and PQPA-Fe were prepared to be used as kits and fluorescence display materials for the detection of Fe³⁺and F^-.In the third part,we designed and synthesized the pyridinium modified decane DPD as the guest,and continued to use the 8-hydroxy quinolone functionalized pillar[5]arene QP5 as the host.The host QP5 and guest DPD were used to construct a new pillar[5]arene-based supramolecular polymer network SPN-QP in a mixed solution of DMSO/H₂O?8:2,v/v?.Surprisingly,when Ag⁺and I^-was continuously added to SPN-QP system,an unexpected strong warm-white fluorescence emission was observed.After careful investigation,we found that the strong warm-white fluorescence emission could be attributed to the in situ formation of AgI quantum dots under the confinement of the supramolecular polymer network SPN-QP.More importantly,through the approach of AgI quantum dot generation,ultrasensitive detection of Ag⁺and I^-was achieved.At the same time,the dry powder of the supramolecular polymer network SPN-QP can efficiently remove Ag⁺from the aqueous solution.This study not only provides a new method for the preparation of AgI quantum dots and provides a new idea for ultrasensitive detection,but also expands the application field of supramolecular functional materials.In the fourth part,in order to more easily and efficiently construct new supramolecular materials,and to fully play the important role of8-hydroxyquinoline in QP5 molecule,we studied the ability of QP5 to form supramolecular polymer metallogel through coordination with metal ions.Studies have shown that QP5 and Al³⁺can construct a stable supramolecular polymer metallogel QP5-AlG with aggregation induced emission?AIE?effect in DMSO/H₂O?8:2,v/v?mixed solution.Interestingly,the QP5-AlG shown multiple external stimuli-responsive behaviors such as temperature,guest compounds,acid,base and so on.Meanwhile,the QP5-AlG can be used as a fluorescent material for detection of Fe³⁺,F^-,trifluoroacetic acid?TFA?and triethylamine?TEA?by different fluorescence states?“on”or“off”?.In addition,the QP5-AlG xerogel can effectively adsorb Fe³⁺from aqueous solution,and the gel film based on QP5-AlG can be used as a stimuli-responsive intelligent fluorescence display material.This research can not only detect and separate Fe³⁺in water with high selectivity and sensitivity,and efficiently detect F^-in water,but also provide insights for the development of new multifunctional supramolecular materials.