Synthesis And Properties Of A Novel BODIPY Derivative Fluorescent Dye And Monomolecular White Light Compound

Fluorescent dyes are indispensable tools in all fields of modern science and medicine,including clinical diagnostics,biotechnology,material chemistry,analysis and environmental chemistry.With the rapid development of technology,thousands of fluorescent dyes have been developed.After half a century of development,BODIPY has become an important class of fluorescent dyes with good photophysical properties and photochemical properties,such as high fluorescence quantum yield,high molar extinction coefficient,easy structural modification through chemical methods and better photothermal stability.At the same time,most of the BODIPY fluorescent dyes also have some drawbacks,such as small Stokes shift,short emission wavelength,low synthesic yield of raw materials and poor exsolubility in water.The biggest shortcoming is poor biological water solubility,which to a large extent limits the application in water environment and life.Therefore,the future research will be devoted to improving the water-solubility of the fluorescent dyes,increasing their fluorescence emission wavelength and other characteristics,and further looking for shorter synthetic routes,more accessible raw materials and simpler purification methods.In this paper,a series of derivatives were designed and synthesized with the new BODIPY parent nucleus as the framework,and their spectral properties were studied.In the first chapter,the introduction briefly describes the principle of fluorescence generation and the types of fluorescent dyes,introduces the synthesis method of BODIPY,and emphasizes on the wide application of BODIPY fluorescent dyes in biological imaging,organic light-emitting diodes,photodynamic therapy,fluorescent probes and other fields.In the second chapter,a series of novel BODIPY derivatives were synthesized by introducing coumarin fluorophore into meso of BODIPY parental nucleus,introducing aldehyde group at site through Vilsmerier-Haack reaction and Knoevenagel condensation reaction for further functionalization.First of all,compared with the traditional BODIPY,the product purification is more convenient,and the yield of the synthesis is higher.In addition,in order to improve its photophysical properties,different groups are introduced into the?-area,and the conjugated system of molecules is expanded to make its maximum emission wavelength red shift.Finally,through a series of tests and property studies,a series of derivatives were synthesized,all of which had undergone fluorescence resonance energy transfer to varying degrees,resulting in a pseudo-stoker displacement greater than 100 nm.The third chapter describes the introduction of different groups in the?-area of the new BODIPY so as to develop two fluorescence probes which can detect Cu²⁺and CN^-respectively,and study the mechanism of the probe in identifying the target compound.The probe is a"Turn-on"type fluorescent probe based on Cu²⁺induced molecular enucleation.Another probe is a"Turn-off"type fluorescent probe based on CN^-destruction conjugate system.By studying the spectral data,we found that both of these probes have high selectivity and sensitivity as well as low detection limit,and they can visually observe the obvious color change and fluorescence change before and after the probe reacts with ions.In the fourth chapter,the design and synthesis of single molecule white light emission were introduced.BODIPY and coumarin are connected by alkyl chain,and a series of pyridine salt compounds are synthesized,which prevent the fluorophore fluorescence resonance energy transfer between the two fluorophore groups,thus achieving the dual fluorescence emission behavior.Compound get double emission peak height in different excitation wavelength,show the polychromatic light luminescence,under certain excitation wavelength,implements the approximation in fluorescence emission of white light,fluorescent amount when fluorescence quantum yield is low,but such compounds do not implement solid white fluorescent emission.However,the innovative design of this monomolecular compound with white light emission in solution has laid a certain foundation for the chemical research of white light emission even solid monomolecular white light emission in the future.