Synthesis And Properties Of Diarylethene Sensors Based On Rhodamine 6G And Fluorescein Groups

In recent years,the fluorescent sensors have been widely reported,because it has various advantages and characteristics.Among the many reported fluorescence sensors,fluorescence sensors based on diarylethene have attracted the attention of many chemists.The sensors have been widely used in many fields such as chemical and biological analysis,environmental monitoring and cell imaging.Diarylethene molecules were known as photochromic materials with the greatest potential,and can switch between open and closed circular structures under the irradiation of certain wavelengths of UV/Vis light.In addition,the materials have the preference of rapid response,excellent thermal stability,and excellent fatigue resistance.Therefore,the main trend of our research is to design and synthesize specific diarylethene derivatives with various functions,such as ion detection,pH effect,and acid-base response.In general,a fluorophore or a functional group was introduced into a diarylethene molecule to form a new type of diarylethene fluorescence sensor.In summary,six kinds of fluorescence sensors based on diarylethene have been designed and synthesized in this paper.Detection of different ions,acid-base and photochemical properties can be achieved by changing different fluorophores or using different diarylene precursors.The main research contents are as follows:In chapter 1,the research background of fluorescent sensors,the research progress of diarylethene derivatives and its application in biological field,and the research overview of Rhodamine 6G derivatives and fluorescein derivatives in fluorescent sensors were introduced.By systematically studying the photochemical properties,the research content of this paper was proposed.In chapter 2,a novel diarylethylene derivative DTR-1O with a rhodamine 6G hydrazide fluorophore has been synthesized by Schiff base method.Multi-responsively photoswitchable properties were achieved by using the regulation of UV/Vis light and other chemical substances.The test results show that the compound could be served as fluorescent sensor to detect Fe³⁺.In chapter 3,rhodamine 6G fluorophore was linked with the compound of salicylidene diarylethylene,a multifunctional DTR-2O was synthesized.The experimental results show that DTR-2O could sequential recognize Cr³⁺and CO₃^2-in methanol/water solution?v/v=4:1?.When Cr³⁺was added to the solution of DTR-2O,the fluorescence intensity was enhanced obviously.After CO₃^2-was added the solution of DTR-2O-Cr³⁺,the fluorescence was quenched to the original solution state.In addition,when Cu²⁺was added to the N,N-dimethylformamide solution of DTR-2O,it could serve as a naked-eye colorimetric sensor for detection of Cu²⁺.In chapter 4,a functional diarylethene DTR-3O with a triazole group as the intermediate linker have been synthesized by Click chemistry.The compound can distinguish Cu²⁺and Fe³⁺in acetonitrile/water?v/v=1:1?solution.The photochromism and fluorescence response of Cu²⁺were tested,and the performance of the fluorescence switch was studied for Fe³⁺.The results show that the compound can be used as a multifunctional fluorescent probe to detect Cu²⁺and Fe³⁺.In Chapter 5,three diarylethene fluorosensors DTF-4O,DTF-5O,and DTF-6O were designed and synthesized by the introduction of a fluorescein hydrazide functional group in the form of Schiff base into the different diarylethene.The test results show that only compound DTF-4O has specificity and highly selective recognition for Hg²⁺in acetonitrile solution.Furthermore,it can be effectively modulated by Hg²⁺/EDTA and UV/Vis irradiation in acetonitrile solution,and the compound DTF-4O could be served as a flurescent sensor for selectively recognition of Hg²⁺.