Design And Synthesis Of Acridone Organic Fluorescent Materials

In recent years,organic light-emitting materials have attracted attention in applications such as organic light-emitting diodes?OLEDs?,fluorescent sensors,piezochromic materials,ion detection and so on.It is important to design and synthesize a novel?-conjugated system and study the relationship between its molecular structure and properties.In general,the preparation of such materials with different emission color is mostly achieved through Fluorescence the covalent modification of chemical structures.The organic light-emitting device requires the luminescent material to have a high fluorescence quantum yield,great stability,awesome stimuli responsivenes,and excellent processability and moldability in a solid film state.Therefore,it is particularly important to synthesize an organic luminescent material having excellent properties and high solid-state fluorescence quantum efficiency.Acridone derivative have rigid?skeleton,outstanding stability,and excellent luminescent proerties.The have been used organic luminescence many years ago.In this paper,we synthesized a series of acridone derivatives with different substituents.Self-assembly,piezochromic,acid/base response and AIE properties were studied to obtain luminescent materials with great performance.At the same time,the relationship between molecular structure,intermolecular interaction and material properties is deeply understood.In this paper,we carry out molecular expansion with acridone as the core,and design and synthesize two different series of?-conjugated systems.The main findings of the paper are as follows:This article is divided into three chapters,the main contents are as follows:In chapter ?,the application and development status of organic luminescent materials based on acridone,?-diketone boron difluoride and cyanostyrene are briefly introduced.In chapter ?,we synthesized two?-diketone difluorodifluoride derivatives,named ADBF₂-a and ADBF₂-b.ADBF₂-a has a high fluorescence quantum yield in various solvents,while ADBF₂-b has a TICT?twisted intramolecular charge transfer?emission in a polar solvent and the fluorescence is significantly quenched and red-shifted.ADBF₂-b also exhibits reversible emission On/Off switching in solution and in film towards volatile acid/base stimuli.We systematically studied the fluorescence response properties of ADBF₂-a and ADBF₂-b solids to mechanical,organic solvent and other stimuli and found ADBF₂-a solids with different emission colors such as green,yellow-green and orange-red.The relationship between their photophysical properties and molecular aggregation states has been enclosed in this study.In chapter ?:Chapter 3:A series of acridone-substituted cyanostyrene compounds AD-n?n=1?2?3?were synthesized by Ullmann reaction based on acridone cyanostyrene units.The results show that in common organic solvents,AD-n?n=1?2?3?all have the same absorption band(?_ab=380 nm)attributed to acridone.As the polarity of the solvent increases,AD-1 has only a single emission band(?_em=407 nm)attributed to acridone,while AD-2 and AD-3 have new emission bands.AD-3 shows a positive solvation discoloration effect.AD-1was found to have aggregation-induced luminescence enhancement?AIE?properties.We also studied the piezochromic properties of AD-n?n=1?2?3?and found that the AD-3 solid powder can be in the yellow crystalline state and the blue amorphous state under the stimulation of mechanical force and organic solvent molecules,Fluorescent transfer switches that can achieve different emission colors.