Study On The Bonding Behavior And Functional Application Of Calixpyridinium Salts And Sulfonated Calixarenes

In recent 30 years,supramolecular chemistry,as a new interdiscipline,has been regarded as the frontier of contemporary science and the future of chemistry.At present,supramolecular complexes have been thoroughly studied by scientists based on the first,second and third generation of macrocycles（crown ether,cyclodextrin,calixarene）.The research on the macrocycles has also been carried out,such as cucurbituril,modified pillararene,cyclic peptide and fullerene.Our research group mainly studies the preparation and application of supramolecular functional materials based on calixpyridinium and organic anion guests.Firstly,I have supplemented and sorted out the previous work:（1）We successfully constructed calixpyridinium-ribonucleic acid（RNA）supramolecular amphiphilic assembly.After that,I carried out the load and release of Nile red,a hydrophobic drug model in vitro,and completed subsequent cell experiments.As a result,the amphiphilic assembly could be used as a targeted drug delivery material at the tissue where RNase A was overexpressed.（2）Our studies achieved p H-induced color change from assembly to recognition of the calixpyridinium-pyrroloquinoline quinone disodium salt（PQQ-2Na）system.It indicated that calixpyridinium-PQQ-2Na was applied to be a controllable release model in vitro.During the summarization of the above work and previous literature,I came to know that porous solid materials have a high specific surface,different pore shapes and sizes,permanent nanopore,other diversified structural and functional characteristics.Traditional porous materials include zeolite,porous carbon and other inorganic frameworks.While emerging materials,such as metal-organic frameworks（MOFs）,covalent organic frameworks（COFs）and porous polymers,have also attracted much attention.These materials play important roles in modern industrial development and human life,such as energy storage,catalysis,adsorption/separation,sensing,drug delivery,and so on.However,most of them are porous materials constructed by coordination or covalent bond as driving forces,while supramolecular organic frameworks（SOFs）constructed by the weak non-covalent bonds are more flexible and relatively simple to be prepared.In order to study supramolecular organic porous materials based on macrocycle-macrocycle,I selected calixpyridinium and a series of p-sulfonatocalix[n]arenes to study their molecular bonding behavior and functional applications.My main work in the master stage is as follows:1.The development of supramolecular chemistry and porous materials was briefly summarized.The molecular recognition and molecular assembly systems constructed by calixpyridinium and different types of anionic guests were discussed.And the negatively charged macrocycle p-sulfonatocalix[n]arenes were briefly introduced.2.We synthesized calixpyridinium and a series of p-sulfonatocalix[n]arenes,including p-sulfonatocalix[4,5]arene and p-sulfonatothiacalix[4]arene.On this basis,the bonding behaviors of calixpyridinium with SC4A,STC4A,or SC5A were studied.It was found that calixpyridinium formed simple complexes with SC4A,STC4A or SC5A.3.We synthesized calixpyridinium and p-sulfonatocalix[8]arene with a larger cavity size.Next,we studied the bonding behavior between calixpyridinium and SC8A.It was obtained that calixpyridinium and SC8A formed supramolecular amphiphilic assembly.The different geometries and the number of cavities may lead to the different bonding behaviors.Therefore,we synthesized bis-p-sulfonatocalix[4,5]arenes with two cavities.And then,we studied the bonding behaviors of calixpyridinium with bis-SC4A or bis-SC5A respectively.The same result as calixpyridinium-SC8A was obtained.In other words,calixpyridinium with bis-SC4A and bis-SC5A constructed supramolecular assembly.All of them were prone to precipitate.Thus,two different systems were formed:molecularrecognitionsystems（calixpyridinium-SC4A,calixpyridinium-SC5A,calixpyridinium-STC4A）and molecular assembly systems（calixpyridinium-SC8A,calixpyridinium-bis-SC4A,calixpyridinium-bis-SC5A）.4.Comparing the results of these basic experiments,the introduction of the S atom into the skeleton of STC4A increases the size of its cavity and the number of recognition sites,which is more conducive to recognition.Therefore,the critical bonding concentration of calixpyridinium and STC4A was one order of magnitude smaller than the other two groups in the recognition systems.Different bonding behaviors may be ascribed that SC4A,STC4A and SC5A have only a single cavity,while SC8A,bis-SC4A and bis-SC5A have double cavities.Finally,the regulation experiments of temperature and p H were studied.5.When exploring the bonding mode through ~1H NMR spectra,I found that no matter the simple complex or advanced assembly formed by calixpyridinium and p-sulfonatocalix[n]arenes,they are easily precipitated due to strong electrostatic interaction.After separating the precipitation,corresponding solid materials can be got,and their different dye absorption efficiency was explored.The results showed that congo red,methylene blue and crystal violet can be effectively adsorbed,but rhodamine-B and methyl orange could not be adsorbed.Eventually,it was achieved the separation of different dyes according to the selective adsorption of solid materials.