Based On Cyanostilbene Schiff Base Synthesis And Properties Of AIE Probe

The advent of Aggregation Induced Emission（AIE）materials has greatly promoted the development of organic materials and broadened their practical applications in sensors,biological imaging,and disease treatment.AIE f luorescent probe object recognition has the advantages of good fluorescence performance,simple preparation and modification,sensitivity and high efficiency,which greatly eases the limitations of detection conditions and improves the efficiency of substance identification.AIE fluorescent probes are used in heavy metal recognition,cell imaging,protein target recognition and other fields have wide application value.After the AIE molecule is derivatized,its twisted flexible structure is more sensitive to changes in the surrounding microenvironment.When a host-receptor structure is present,subtle environmental changes can be detected,which can give it a highly selective,highly sensitive host and guest ion.Recognition performance,structural modification of functional molecules with AIE effect,and research on the recognition performance of host and guest are important research directions in this field.In this paper,based on the theory of intramolecular charge transfer（ICT）effect,restriction of intramolecular motions（RIM）mechanism,and fluorescence resonance energy transfer（FRET）effect,the cyano stilbene is used as the precursor,which is connected to different functional groups through etherification and condensation.The synthesis of cyanostilbene derivative with different host-acceptor cyanostilbene derivatives was carried out,and its host-guest recognition performance was measured.The main contents are as follows:Firstly,synthesis of cyano stilbene thiosemicarbazide compound 4,and research on its photophysical properties found that compound 4 produces a fluorescence quenching phenomenon after complexation with palladium ions,and has good specific recognition performance;it can be convenient and fast for sewage The qualitative detection of palladium ions has certain application value.Secondly,symmetric cyano stilbene dimers with salicylaldehyde and C and O as bridged chains.Compounds 5 and 7 were prepared by the reaction.Research shows on their photophysical properties found that compounds 5 and 7 were in Hg²⁺and arginine were quenched after complexation,which indicated that compounds 5 and 7had good recognition effect on Hg²⁺and arginine,respectively.Thirdly,symmetric cyano stilbene derivatives with 2,4 dihydroxybenzaldehyde and C,O as bridged chains,to prepare compounds 8 and 10 respectively.The results showed that the fluorescence attenuation phenomenon occurred after compound 8complexed with guanine,and the fluorescence quenching phenomenon occurred after compound 10 complexed with picric acid,indicating that compounds 8 and 10 had specific recognition functions for guanine and picric acid,respectively.Fourthly,synthesizing perylene imide as a symmetric perylene imide derivative16 with a chiral cyano stilbene unit on the backbone.The results show that the introduction of two cyano stilbene units on the fluorinated anhydride skeleton can achieve the fluorescence emission of fluorinated anhydride in the solid powder state,and the fluorescence resonance energy transfer（FRET）effect is observed between the cyano stilbene unit and the fluorene core.Compared with the traditional ACQ control compound 14,it has good AIE and liquid crystal performance.