Preparation And Optical Properties Of Pyridine-containing Tetraarylethylene Aggregation-induced Luminescent Materials

Traditional organic light-emitting materials are often affected by the quenching of aggregated fluorescence,and their fluorescence emission is weak in the solid or aggregated state,which greatly limits the application of organic light-emitting materials.In 2001,Benzhong Tang's group first reported Aggregation-induced emission(AIE)phonemona,whose inaterials show weak emission in the dilute solution state,and strong emission in the aggregate state or in the solid state.Organic light-emitting materials with AIE activity largely make up for the weak luminescence of traditional organic light-emitting materials in the aggregated state.Therefore,AIE materials have received great attention and are used in many fields.In this paper,a number of AIE active materials containing pyridine structure have been prepared by taking advantage of the characteristics of easy adjustment of the electron density and alkalinity of the pyridine structure,and the following work has been specifically carried out:1.The pyridine group were used to replace the phenyl group of the classic AIE molecule tetraphenylethylene(TPE),and a series of tetraarylethylene materials containing pyridine structure were prepared by further nitrogen oxidation and methylation.Then by changing the ratio between good solvents and poor solvents to study their optical properties to futher explore their applications.The results showrf that when the benzene rings were substituted by pyridine groups,their optical properties were very different from that of TPE.The change of the electron density of traditional materials could lead to change their optical properties.The research results demonstrated that electronic effects also affected the optical properties of AIE materials.This work indicated that the introduction of pyridine structure into tetraarylethenes could adjust their optical properties,thereby increasing the application range of related materials.2.The pyridine group was introduced into the classic AIE molecule TPE through single bond and triple bond,and then the nucleophilicity of pyridine was used to form salts with chiral binaphthyl benzyl bromides to synthesize materials R-BINOL-1-4 and S-BINOL-2/4.By adjusting the ratio of mixed solvent THF/H2O,the optical properties of these materials were studied.Fluorescence spectra showed that the materials had significant AIE characteristics;further research showed that R,S-BINOL-2,4 could be adjusted the aggregation induced circular dichroism(AI-CD)signals and the aggregation induced circularly polarized luminescence(AI-CPL)signals.The R and S configuration showed mirror symmetry CD and CPL signals,and the maximum |gium| value of compound S-BINOL-4 in the film state could reach to 0.02.This work has prepared AI-CPL materials that had both AIE and AI-CPL properties,The research results provided a way for the application of pyridine-eontaining aggregation-induced luminescent materials in circularly polarized luminescence3.Two materials,TPE-yne-2Py and TPE-2Py,were designed and synthesized,both of which showed significant AIE characteristics.Subsequently,the two materials were applied to the detection of trinitrophenol explosives.The results showed that both materials could detect trinitrophenol in trace amounts,and the detection limitation of TPE-2Py was as low as 5 ?M.This work was the application of pyridine-containing AIE materials in sensors and provided a new method for the detection of trace explosives.