Design,Synthesis And Properties Of AIE Compounds

In 2001,Tang's group discovered a class of compounds that emit little light in dilute solutions and increase their luminescence in aggregated state and named aggregation-induced emission(AIE).Traditional fluorescent compounds have the effect of aggregation caused quenching(ACQ)which has been hindered in practical applications,and the discovery of aggregation-induced luminescent substances solves this problem,making the field attracted more and more researchers' attention.Aggregation-induced emission compounds have broad prospects in light-emitting diodes,cell imaging,chemical sensors and other directions.In this thesis,two kinds of compounds,including diphenylquinoxaline as the core compound and allyonitrile compounds,were synthesized and characterized.The AIE properties of these molecules were studied and their AIE properties were explained.And use these compounds AIE nature and chemical properties of ions.(1)Using diphenylquinoxaline derivatives as nucleus,compounds A1?A6 with AIE properties were designed and synthesized,named 2,3-diphenylquinoxaline(A1),dimethyl-4,4'-(quinoxaline-2,3-diyl)dibenzoate(A2),2,3-bis(4-bromophenyl)quinoxaline(A3),6,7-diphenyl-[1,3]dithiolo[4,5-g]quinoxaline-2-thione(A4),dimethyl-4,4'-(2-thioxo-[1,3]dithiolo[4,5-g]quinoxaline-6,7-diyl)dibenzoate(A5),6,7-bis(4-bromophenyl)-[1,3]dithiolo[4,5-g]quinoxaline-2-thione(A6).The UV-Vis spectra and fluorescence spectra were characterized and the single crystal structure of the compound was obtained.The experimental results show that the compounds A1?A6 have AIE properties.The mechanism of the AIE phenomenon of the compounds is found through the analysis of the crystal structure.Restriction of intramolecular rotation(RIR)in the aggregates is the cause for the AIE effect.The experimental results show that the compound A4?A6 obtained by using quinoxaline as a nucleus and linking 1,3-dithio-2-thione can react with mercury ions and can be used for detecting mercury ions.(2)Three allylnitriles B1?B3 were synthesized and characterized,named 2-phenyl-3-(4-(pyridin-4-yl)phenyl)acrylonitrile(B1),methyl-4-(1-cyano-2-(4-(pyridin-4-yl)phenyl)vinyl)benzoate(B2),4-(1-cyano-2-(4-(pyridin-4-yl)phenyl)vinyl)benzoic acid(B3).The UV-Vis spectra and fluorescence spectra were characterized.The experimental results show that these compounds have AIE properties,and the mechanism of AIE phenomenon of these compounds is that the formation of J-aggregates leads to the co-planarization of the compounds.Pyridine compounds in the probe compounds can react with hydrogen ions,the experimental resulshow that the compounds can be used to detect hydrogen ions.