Synthesis And Properties Of 2-substituted BODIPY Fluorescent Dye

The progress of modern organic chemistry has promoted the development of dye chemistry.Currently,organic chromophores deserve a great deal of attention,and many efforts are being made to design organic dyes with tailor-made molecular structures and photophysical properties,to be applied in advanced applications.Among all the available organic dyes with adjustable key properties fulfilling the specific demands of the different application fields,those known as BODIPYs are in the forefront.BODIPY not only has excellent photophysical and chemical properties,but more importantly,its parent structure is easy to be modified.Through simple structural modification,the optical properties of BODIPY can be improved to apply to various fields,such as medicine and materials.In the second chapter,BODIPY with meso-position substituted by benzocoumarin was synthesized from 5,6-benzocoumarin-3-carbonyl chloride and 2,4-dimethylpyrrole as raw materials.The aldehyde group is introduced into the 2-position by the Vilsmeier-Haack reaction.Finally,a series of new BODIPY derivatives were synthesized by the Knoevenagel condensation reaction.The alternate connection of single and double bonds and the aromatic ring expanded the molecular conjugate system.All intermediates and target compounds were characterized by NMR and NMR.The target compound was further studied for its optical properties by UV-visible absorption spectrum,fluorescence emission spectrum,absolute quantum yield and fluorescence lifetime.Most of the target products showed good solubility in solutions of different polarities.In the dilute solution,both ultraviolet absorption and fluorescence emission showed a significant red shift,and the CIE coordinates were dispersed in the yellow and red regions,and the Stokes shift was significantly increased.Some target compounds were further red-shifted in the solid state and distributed in the red area in the CIE coordinates.In the third chapter,a photochromic intermediate of bisthienylethene unit was synthesized by Suzuki coupling reaction,and the compound was obtained by condensing the aldehyde group with 2,3-diaminomaleonitrile.Target compound had good photochromic properties and fatigue resistance.The bisthienylethene parent compound has very weak fluorescence.It is a feasible strategy to incorporate a fluorophore into bisthienylethene unit to synthesize a fluorescence-controllable photochromic compound.The target compound was designed and synthesized by incorporating dithienylethylene into the BOPHY fluorophore.The photochromic properties of the target product were studied by UV-visible absorption spectrum and fluorescence emission spectrum.The results showed that the fluorescence changed can be adjusted while the compound underwent reversible photochromism by excitation with 532 nm wavelength light.Compound also had good fatigue resistance.BOPHY is a new class of highly fluorescent organoboron compound.The new symmetric structural motif,the unusual absorption and emission properties,and better photostability have attracted considerable attentions for the development of various functional chromophores.In this work,we synthesized a BOPHY derivative(BOPHY-CHO)via the post derivatization of BOPHY at the ?-position with an aldehyde.The target product was obtained by the condensation of 2,3-diaminomaleonitrile with an aldehyde group.Target compound had very weak fluorescence.However,it displayed significant fluorescence enhancement in the presence of Cu2+.Further research showed that it was a highly selective and sensitive fluorescent probe.A fluorescence turn-on sensor for Cu2+ ions was therefore developed.