Preparation And Properties Of Several Organic Functional Macrocyclic Molecules

With the rapid development of supramolecular chemistry,the composite materials based on cyclodextrin and pillar[n]arenes are playing an increasingly important role in the fields of sensing detection,biological intelligent materials,functional nanomaterials and so on.As the main body of the second generation macrocycle,cyclodextrins are easy to modify,has good biocompatibility,good water solubility and good host-guest properties and are widely used in sensing detection,drug inclusion,adsorption separation and drug delivery.As the fifth generation of macrocycle,pillar[n]arenes are easy to synthesize,symmetrical in structure,easy to derivate and have good host-guest complexation ability.They are widely used in the construction of functional nanomaterials such as adsorption separation,artificial nanochannel,catalysis,artificial light-harvesting system and drug delivery.In this paper,a fluorescence sensor based on diethylenetriamine-β-cyclodextrin and phenylboronic acid functionalized pillar[5]arene and a supramolecular drug delivery system based on water-soluble pillar[n]arenes were constructed,and their properties and functions were studied in detail.The full text is mainly divided into four chapters.In the first chapter,carbon quantum dots modified with diethylenetriamine-β-cyclodextrin were synthesized and the common cations in aqueous solution were detected.Chapter 2 and Chapter 3 construct a supramolecular drug delivery system based on water-soluble pillar[n]arenes and podophyllotoxin prodrugs,which can release anticancer drugs under the stimulation of p H and glutathione to achieve effective drug delivery and controlled release.In Chapter 4,phenylboronic acid functionalized pillar[5]arene were synthesized and used for sensing detection of common cations in solution.The thesis mainly includes the following five parts:In the first part,the development of supramolecular chemistry is summarized.First,the development history and main applications of cyclodextrins are briefly summarized,and then the development,synthesis and derivatization of pillar[n]arenes are mainly introduced.At the same time,the research progress of pillar[n]arenes in the fields of adsorption and separation,catalysis,light-harvesting system,artificial nano-channel and drug delivery are briefly reviewed.In the second part,diethylenetriamine-β-cyclodextrin-modified carbon quantum dots（3N-CQDs）were synthesized via a one-step hydrothermal method using citric acid as the carbon source and diethylenetriamine-β-cyclodextrin（3N-β-CD）as the nitrogen source.The successful preparation of 3N-CQDs were revealed by infrared absorption spectroscopy,ultraviolet（UV）-visible absorption spectroscopy,fluorescence spectroscopy,XRD,XPS,TEM,and TG.Further spectroscopic studies showed that the synthesized carbon quantum dots offered good anti-interference capability.The relative fluorescence quantum yield was 67.2%.The limits of detection for Hg²⁺and Fe³⁺were 0.25μM and 0.57μM,respectively.Cytotoxicity and imaging studies showed that the prepared carbon quantum dots had low cytotoxicity,good biocompatibility,and good cellular imaging capability for He La cells.They offered fluorescent sensing of Hg²⁺and Fe³⁺in live cells.Therefore,3N-CQDs were ideal fluorescent probes for the detection of Hg²⁺and Fe³⁺in water.In the third part,in order to improve the drug loading efficiency of the supramolecular drug delivery system,based on the prodrug strategy,we designed and synthesized podophyllotoxin prodrug molecule（G1）containing disulfide bond,which can further self-assemble with water-soluble phosphate pillar[6]arene in aqueous solution to form supramolecular nanoparticles with glutathione response（GSH）.Drug release studies have shown that podophyllotoxin can be released faster under conditions of weak acid and high GSH concentration,possibly because both weak acid and GSH environment are conducive to the disintegration of nano assemblies.This study shows that supramolecular nanoparticles based on GSH response have potential application value in the field of cancer therapy.In the fourth part,in order to further improve the drug loading efficiency and release efficiency of supramolecular drug transport,based on the same prodrug strategy,we designed and synthesized 4’-demethylepipodophyllotoxin prodrug molecule（G2）containing ester group and benzene sulfonyl group.The water-soluble carboxylate pillar[5]arene can form supramolecular nanoparticles with p H and GSH stimulation response in aqueous solution through the host-guest complexation.The nanoparticles are very stable under physiological conditions,but can rapidly release4’-demethylepipodophyllotoxin in the environment of micro-acid and high GSH concentration.To sum up,this dual-response supramolecular nanoparticles have important significance in the treatment of cancer.In the fifth part,phenylboric acid functionalized pillar[5]arene（P5B）were synthesized for the first time and used for cationic sensing.Preliminary results showed that P5B could selectively detection Fe³⁺from 21 common cations in acetonitrile:water=6:4,and the presence of other cations did not affect the fluorescence intensity of P5B,indicating that P5B has high selectivity for Fe³⁺recognition.Further spectroscopic studies have shown that P5B has a slight time response and good anti-interference ability for the recognition of Fe³⁺,and the minimum detection limit for iron ions can reach 1.1μM.Therefore,this probe has great application prospects in the field of Fe³⁺detection in solution.