Construction And Properties Of Tunable Fluorescence Molecules And Supramolecular Assembly Systems

Organic fluorescent molecules can not only be used in fine chemical industries of ink as fluorescent dyes,but also in new fields such as chemical sensing,fluorescent probes,organic field-effect transistors,and biological imaging.The stability of the fluorescent functional molecules,which prepared by covalent organic synthesis,is always satisfied.But they always have the problems of the synthesis and low yields.Interestingly,the supramolecular self-assembly methods based on non-covalent interactions can often prepare desired fluorescence functional molecules with almost quantitative yield.However,compared with the covalent organic synthesis way,the stability of self-assembly by noncovalent interactions is a bit weaker.It is one of the research hotspots in the field of supramolecular fluorescence functional molecules and materials to comprehensively utilize the advantages of covalent organic synthesis and noncovalent interactions self-assembly strategy.In this thesis,a series of fluorescent molecules with different substituents were designed and synthesized.Besides,a series of fluorescent functioned metallacycles were constructed by supramolecular coordination-driven self-assembly strategy,leading to the tunable properties of the new fluorescent functional materials.The process and the mechanism of supramolecular coordination-driven self-assembly were systematically studied by fluorescence technology.The main points of the thesis can be separated into the following three parts:1.Tunable fluorescence property and white light emission of triphenylamine derivativesTwelve triphenylamine(TPA)derivatives with different substituents and intramolecular charge transfer(ICT)characteristics were designed and synthesized in this chapter.This series of molecules not only have high fluorescence quantum yields and large Stokes shift,but also can be able to achieve multi-color fluorescence emission including white light emission through reversible adjustment of acid and base.They were also constructed as solid film materials with high sensitivity response to acid and base.At the same time,the visible "Xiang Yun" patterns under the wavelength of 365 nm have been successfully painted by using inkjet printing technology,which shows the potential application in the field of anti-counterfeiting.2.The construction of the metallacycles based on triphenylamine and their applicationsOn the basis of the first part of the research,in this chapter,a series of triphenylamine metallacycles with different substituents,based on the skeleton of the triphenylamine derivatives,were constructed by coordination-driven self-assembly.The structure characterization,luminescent properties and halide ion response tests were carried out as follow.The effects of substituents on the luminescence properties of molecules were systematically investigated by spectral experiments and the radiation and non-radiation rate constants of triphenylamine ligands and metallacycles.It has been successfully used in the field of fluorescent molecular ink with the painting of the traditional Chinese paper-cut patterns,which displays its great potential as a kind of supramolecular organic fluorescent functional material in information storage and anti-counterfeiting.3.Real-time monitoring of the process of assmbly by FRET technology and the study of its propertiesIn this chapter,bifunctional metallacycles with high fluorescence quantum yield and high FRET efficiency were constructed by introducing coumarin and fluoroboron pyrrole.The formation of supramolecular coordination metal assembly,the dynamic and reversible ligand exchange behavior,the ion response assembly and the disassembly process in real-time were monitored by utilizing FRET technology,followed by the deep exploration of the mechanism of the supramolecular assembly.