Construction And Study Of Properties Based On Coumarin Functionalized Pillar [5] Arene Fluorescence Sensor

Supramolecular chemistry is also defined as chemistry beyond molecules,which indicated that design and realize a functional molecular system maintained through non-convent.In the research of supramolecular chemistry,self-assembly is the core of supramolecular chemistry,and host-guest chemistry is the basis of research.The construction of host-guest chemistry is related to the development of the macrocycle.Especially in recent decades,the birth of new host macrocycles provides a good opportunity for the development of supramolecular chemistry.In2008,Ogoshi first reported a new macrocycle compound-pillar[n]arene,the special structure of pillar[n]arenes endow them special properties,which provide a good opportunity for the development of novel fluorescence function sensor.In 2001,the aggregation induced emission（AIE）effect was first reported by Tang,which solved the long-standing problem that the fluorescence reduction or quenching caused by traditional molecules in the aggregation state.Therefore,how to combine aggregation induced emission with supramolecular chemistry and construct a new fluorescent sensor provide important research value.In this paper,the recognition of fluorescent sensors based on macrocycles were investigated in three parts:（1）We summarized the the brief development history of supramolecular chemistry and fluorescent sensors by refering the related literatures and the importance of ion detection.It focuses on the research progress of the five generations of macrocycles including crown ether,cyclodextrin,calixarene,cucurbituril,and pillar[n]arene in ion and molecular detection and recognition.Simultaneously,it also introduces the development process of each generation of macrocycles.（2）We designed and prepared a coumarin-functionalized pillar[5]arene sensor molecule PX,which exhibited strong aggregation induced fluorescence in binary solution of DMF/H₂O（7:3,v:v）with a quantum yield up to 35.0%.It was found that Fe³⁺,Ba²⁺,H₂PO₄^-and CN^-could be well detected and the detection limit of are 1.67×10^-7 M,5.89×10^-8 M,1.50×10^-7 M and 6.20×10^-7 M,respectively.Simultaneously,the above mechanism was also verified by density functional theory.In addition,PX based test paper and logic gate were also prepared,which easily and quickly detection of ions.（3）Based on the study of the second part,a bilateral coumarin-functionalised pillar[5]arene sensor molecule DPX were designed and synthesied,which also exhibited better AIE effects in a DMF/H₂O（8:2,v:v）system with a quantum yield of 38.0%.DPX served as sensor could selectively detect Fe³⁺、H₂PO₄^-,and also detect Vc through redox reaction.The limit of detection were 2.9×10^-7M,6.1×10^-7 M and 3.5×10^-7M.Compared to PX,the introduction of moreπsystems in the system significantly improved the quantum yield and reached the fluorescence emission maximum earlier,and DPX showed good specificity and stability in ion detection.To further extend the practical application of the sensor,detection films were prepared to facilitate the detection of Fe³⁺.