Study On The Construction And Application Of Aggregation-induced Emission Supramolecular Polymers Based On Host-guest Interaction

Supramolecular polymers originated from the combination of polymer science and supramolecular chemistry.Using the dynamic reversible process between non-covalent bonds,supramolecular polymers not only have the properties of traditional polymers,but also exhibit some new structures and functions.It has a wide application prospect in the preparation of biomedical materials,intelligent functional materials and environmentfriendly materials and other new functional materials.The supramolecular polymer with the aggregation-induced luminescence effect can fundamentally overcome the problem that the aggregation leads to the fluorescence quenching,and the formation of the supramolecular polymer can closely arrange the molecules,and the close alignment between the molecules can provide a higher proportion of the acceptor,a relatively high energy transfer efficiency can be exhibited in the energy transfer process.In this paper,the light-controlled reversible response and the light-trapping performance of the light-controlled light-emitting unit are studied by means of the interaction of the main and the objects with the light-emitting unit as the basic skeleton.This paper mainly develops the following three parts of work:1.Construction of supramolecular polymers based on tetraphenylethene-coumarin skeletonIn this part of the work,the building unit of aggregation-induced emission(tetraphenylethene)was used as the molecular framework,and the naphthalene 7-(4-bromohexoxy)-coumarin group was connected to the molecular skeleton by reasonable molecular design.Through the interaction between host and guest(?-cyclodextrin and coumarin group),supramolecular polymers with aggregation-induced luminescence were constructed.Because the host-guest interaction between coumarin group and ?-cyclodextrin can effectively restrict the rotation and non-radiation relaxation within the molecule,the aggregation-induced luminescence occurs,and the supramolecular polymer aqueous solution shows strong luminescence.At the same time,we realized the reversible conversion between non-covalently bonded supramolecular polymer and covalent-bonded supramolecular polymer by using the phenomenon of photodimerization and depolymerization of coumarin group under UV irradiation.In addition,two kinds of supramolecular polymers can be assembled in aqueous solution to form a spherical aggregate structure,which provides a new method for the construction of novel aggregation-induced luminescent supramolecular polymers.2.Study on supramolecular polymer construction and light-harvesting properties based on tetraphenylethene-naphthalene frameworkIn the work of this part,we build the super-molecular hyperbranched polymer by mixing the tetrastyrene derivative(TPE)and the cucurbit[8]uril(CB[8])in the aqueous solution with the main object between CB[8] and the TPE.The interaction of the host and guest between the CB[8] and the TPE effectively limits the rotation of the molecules and the non-radiative relaxation channels,the polymer emits strong fluorescence in dilute solution.In addition,the supramolecular hyperbranched polymer between CB[8] and TPE was selfassembled in water to a spherical structure of about 60 nm in diameter.An efficient lightharvesting system with a donor / receptor ratio of 200 000:1 was constructed in the aqueous solution by using the spherical supramolecular polymer as the energy donor and the eosin disodium salt(EY)as the energy receptor.The light-trapping system with high energy transfer efficiency and simple preparation method has the potential application value in photocatalysis,light-emitting devices and optical sensors,and our strategy can excite the exploration of a novel light-capturing system based on the supramolecular polymer.3.Study on supramolecular polymer construction and light-harvesting properties based on 9,10-bis((E)-2-(pyridin-4-yl)vinyl)anthracene-naphthalene frameworkIn this part of the work,we mixed CB[8] and 9,10-bis((E)-2-(pyridin-4-yl)vinyl)anthracene(BP2VA)with naphthalene substituted in aqueous solution.And linear supramolecular polymers are constructed by host-guest interaction between CB[8] and BVA.The host-guest interaction between CB[8] and naphthalene effectively limits intramolecular rotation and non-radiative relaxation channels.Thus produce very strong luminescence in dilute solution.The aggregation morphology of the supramolecular polymer in aqueous solution is nanorod structure,and its size distribution range is 60~200 nm.A aqueous lightharvesting system with a ratio of 1250 to 1 was constructed by using supramolecular polymer as energy donor and thiocyanate-5-carboxylic acid(Cy5)as energy receptor.The efficient energy transfer efficiency and the construction of a simplified light capture system provide potential applications in the fields of photocatalysis,light emitting devices and optical sensors,etc.It provides an idea for further exploring the construction of light capture system based on supramolecular polymers.