Synthesis And Properties Of AIE Fluorescent Probes Based On Seven-membered Cucurbit Rings

Host-guest interaction based on cucurbit[n]uril（Q[n]）has been widely reported in recent 20 years.Researchers use the cavity structure of cucurbit[n]uril and guest molecules to assemble to construct supramolecular sensors for catalysis,cell imaging and drug delivery.Fluorescent cucurbit[n]uril has the characteristics of cucurbit[n]uril and generates fluorescence signal.Compared with ordinary cucurbit[n]uril,on the basis of recognition,the analyte can be detected by the change of fluorescence signal and reflect the information of micro area.As a typical Aggregation-induced emission（AIE）molecule,tetrastyrene has the advantages of simple structure,easy synthesis and high fluorescence quantum yield.In this paper,the research progress of cucurbit[n]uril fluorescent probes was firstly reviewed,and the research objectives were established based on the summary.Q[7]was used as the structural platform,and tetrastyrene with AIE property was introduced on its waist to synthesize fluorescent Q[7]with high sensitivity and selectivity.The main contents are as follows:1.Amphiphilic fluorescent cucurbiturils TPE-Q7 and TPE-2Q7 with AIE effect were synthesized by Connecting tetraphenylethylene group to the waist of derivative Q[7],the structures were characterized by NMR,MS and IR.2.The effects of water content and viscosity on the AIE properties of TPE-Q7and TPE-2Q7 were studied by ultraviolet and fluorescence spectra;Diameter and aggregation of TPE-Q7 and TPE-2Q7 in different environments were measured by DLS;The shape of TPE-Q7 in aqueous solution characterized by fluorescence microscope and SEM.3.The recognition of Cu²⁺and Fe³⁺by TPE-Q7 was studied by fluorescence spectroscopy.Calculation of detection limit of fluorescent probe for Cu²⁺and Fe³⁺;The FRET and host-guest interaction between TPE-Q7 and Rhodamine B were studied by fluorescence spectroscopy,ITC and ¹H NMR titration.4.The host-guest interaction mechanism between TPE-2Q7 and BV²⁺,TBuPyP was studied by ultraviolet and fluorescence spectroscopy,ITC,¹H NMR titration.