Study Of The Properties Of Water-soluble Pillar[n]arene With Different Guest Species And Their Applications

The macromolecules,including calixarenes,cyclodextrins,crown ethers,cucurbiturils,and pillararenes,are cyclic oligomers containing repeating units,so they are also called macrocyclic hosts.They can form host-guest complexes with various organic/inorganic guest molecules based on the size of the cavity or their electron density.Among them,the pillararene is a new type of macrocyclic host compound with a columnar structure and an electron-rich cavity.It is easier to be modified chemically than cyclodextrin and cucurbituril,and it has a better rigid cavity than crown ether and calixarene.Therefore,in the past few years,pillararene has shown interesting and unique host-guest recognization properties.This article mainly discusses the self-assembly phenomenon and application of water-soluble pillararene and different guest molecules in water,and the research has been carried out in the following three areas:?1?A new supramolecular amphiphile was successfully constructed based on a water-soluble pillar[5]arene and a coumarin guest?G?with a CO₂-responsive tertiary amine unit and a UV-responsive moiety.The proposed amphiphile has dual response properties of light response and carbon dioxide response.TEM,SEM,DLS,SAXS,and NMR were used to characterize the system's self-assembly process and the resulting assembly,and this amphiphile shows potential applications in the field of"on-demand"load and release of drugs.?2?A mitochondrial-targeted long alkyl chain triphenylphosphine derivative?Compound 6 and Compound 7?was synthesized,and a supramolecular system based on host-guest complexation of water-soluble pillar[5]arene?WP5?was constructed.Wherein,the host-guest complexation of WP5 and proposed guest molecules were studied.The existence of complexation between host and guest was confirmed by ¹H NMR?with peak below 0 ppm?and NOESY spectrum.The fluorescence spectrum was used to compare the concentration-dependence test of the host-guest complexed and uncomplexed guest.It was found that with the increase of the alkyl chain length of the guest molecules,the concentration-dependent fluorescence enhancement effect of compound 7 in water was significantly stronger than Compound 6.Moreover,when the compound concentration exceeds the critical micelle concentration,the compound self-assembles,which effectively isolates the factors that are not conducive to the fluorescence emission in the system,thereby enhancing the system fluorescence.Utilizing the mitochondrial targeting properties of triphenylphosphine derivatives and its complexing properties with WP5 and guest molecules,it is expected to be used in biomedical aspects to enable the controlled release of mitochondrially targeted drugs.?3?A water-soluble pillar[6]arene and WCTV were synthesized and mixed at a ratio of 1:2 to form a supramolecular polymer material.Fourier transform infrared spectroscopy,and solid NMR was used to characterize the prepared supramolecular polymer material.When it was dispersed in an aqueous solution of the dye,it was found that the color of the dye gradually faded with the passage of time;and the solution became almost colorless after30 minutes.The UV spectrum also confirmed that the absorption peak was significantly reduced after 30 minutes.The theoretically calculated dye removal rates are above 85%.Furthermore,the material can be easily regenerated by using a simple washing process without loss of performance.This work provides a method for adsorbing dyes,which is expected to be used in dye adsorption and even sewage treatment.