Fabrication And Study On Solid Fluorescent Dyes Based On Polyarylethylene Sulfur Derivatives

Fluorescent dyes are a new type of functional dyes that have been widely studied in recent years and have promising applications in paper,textile,and plastic fields.However,the ACQ effect or concentration quenching effect of conventional fluorophores makes them unsuitable for applications at high concentrations or as solid particles.The aggregation-induced emission(AIE)is a photophysical phenomenon that is completely opposite to the ACQ effect,and the fluorescence was enhanced accompany by aggregation.Stimuli-response solid fluorescent dyes using fluorescence as a signal have attracted considerable attention in academic and industrial fields due to highly sensitive and rapid responses.In this regard,this project intends to design novel luminescent compounds with AIE and stimuli-response behaviors in the solid-state.Changing the properties of the luminescent compounds by conventional modes,such as oxidation or different substituent position,we will deeply investigate the structure-activity relationship and explore the application of AIE materials in anti-counterfeiting technology.The details are as follows:1)In this article,three sulfur/sulfide/sulfone-based bis(tetraphenylethene)compounds bis(4-(1,2,2-triphenylvinyl)phenyl)sulfane(II-1),bis(4-(1,2,2-triphenyl-vinyl)phenyl)sulfoxide)(II-2),and bis(4-(1,2,2-triphenylvinyl)phenyl)sulfone(II-3)were successfully designed and synthesized.The structures of the compounds were determined using 1H NMR,13 C NMR,and HRMS.All the materials exhibited obvious aggregation-induced emission behaviours.The maximum emission wavelength of compound II-1 in the aggregation state had very little change compared to its oxidation products II-2 and II-3,but the fluorescence intensity remarkably decreased after oxidation.Compound II-3 also exhibited polymorphism properties with different packing modes by introducing electron-withdrawing group sulfone,and the three solid-states could be converted.Compounds II-1,II-2 and II-3W displayed reversible mechanofluorochromism properties.The emission color of them changed from blue to green upon grinding,and the mechanofluorochromism mechanism is proved to be a transition process from crystalline to amorphous state by PXRD measurements.This study is a guideline for designing compounds with different luminescent properties and polymorphism.2)In this article,three new sulfur/sulfide/sulfone-based triphenylethylene derivatives(4-(2,2-diphenylvinyl)phenyl)(phenyl)sulfane(III-1),(4-(2,2-diphenyl-vinyl)phenyl)(phenyl)sulfoxide(III-2),and(4-(2,2-diphenylvinyl)phenyl)(phenyl)sulfone)(III-3)were successfully synthesized,and their structures were determined using NMR spectroscopy,high-resolution mass spectrometry and single-crystal X-ray diffraction.Photophysical property studies showed that compounds III-2 and III-3 showed significantly lower fluorescence intensity compared to III-1,but the oxidized compounds III-2 and III-3 exhibited photochromic properties under UV light irradiation in solution,on silica gel plates,and in the thin film.It was demonstrated that the AIE and photochromic properties of the triarylethylene compounds could be modulated through oxidation of sulfur atoms.The accomplishment of our proposal will be helpful to provide new design strategies for triarylethylene photochromic dyes and adjusting their AIE and photochromic properties through the oxidation of sulfur atoms.3)In this article,two new 2-thienyl/3-thienyl-based tetraarylethylene derivatives 2-(1,2,2-triphenylvinyl)thiophene(IV-1)and 3-(1,2,2-triphenylvinyl)thiophene(IV-2)were successfully synthesized,and their chemical structures were determined by NMR hydrogen spectroscopy,carbon spectroscopy and high-resolution mass spectrometry.The aggregation-induced emission performance study showed that the fluorescence intensity of compounds IV-1 and IV-2 were almost identical in CH3CN/water mixture with fw = 95%,but the maximum emission wavelength was blue-shifted by 34 nm,and the fluorescence colors were blue-green and bright blue,respectively.Compounds IV-1 and IV-2 exhibited excellent photochromic properties in both solution and polymer films,and compound IV-2 also exhibited reversible photochromic properties in the solid state.This study was a good guide to studying the relationship between the isomeric structure and properties.