| Organic fluorescent materials have been developed rapidly in recent decades.They have been widely used in organic solid-state lasers,organic light-emitting diodes,organic field-effect transistors,intelligent materials,bioimaging,biochemical sensing,photocatalysis and other fields because of their advantages of low cost,no heavy metal pollution and easy modification.In this paper,the mechanism and application of organic fluorescent materials are described and studied in detail.A series of 3-amino-fluorene-2,4-dicarbonitrile organic fluorescent materials have been synthesized and achieved great progress in the preparation of organic light emitting diode devices,aggregation induced emission and mechanochromic fluorescence materials,and organic photocatalysis.The main contents and results are as follows1)Study on the relationship between the structure of 3-amino-fluorene-2,4-dicarbonitrile derivatives and the efficiency of OLED devicesA series of 3-amino-fluorene-2,4-dicarbonitrile derivatives were synthesized,including 1-(4-(Diphenylamino)phenyl)-3-amino-9H-fluorene-2,4-dicarbonitrile(la)and its derivatives 1b,lc,1d and le with methyl,ethyl,n-butyl and n-heptyl side chains,and 3-Amino-1-(4-carbazol-9-yl-phenyl)-9H-fluorene-2,4-dicarbonitriIe(2a)and its derivatives 2b and 2c with methyl and n-butyl side chains,as well as 1-(4-(10H-phenoxazin-10-yl)phenyl)-3-amino-9H-fluorene-2,4-dicarbonitrile(3a)and its derivatives 3b and 3c with methyl and n-butyl side chains.The spectral properties of these molecules in solution were studied in detail.These molecules were used eventually as fluorescent materials in OLED devices.Pure organic small molecular thin film devices and PVK-doped thin film devices were fabricated.The electroluminescent efficiency of compounds with different side chain lengths was compared under two device conditions.Finally,the most efficient device was obtained under PVK-doped thin film conditions.The maximum EQE of la is 2.3 14%,and that of 3a is 2.099%.2)Study on the aggregation induced fluorescence and mechanochromic fluorescence of 3-amino-fluorene-2,4-dicarbonitrile derivatives and its precursors containing phenoxazine moiety as donorTwo phenoxazine derivatives:4-(10H-phenoxazin-10-yl)benzaldehyde(3.1)and 1-(4-(10H-phenoxazin-1 0-yl)phenyl)-3-amino-9H-fluorene-2,4-dicarbonitrile(3a)which emit light in solid-state were studied in detail.These two compounds were determined to be aggregation induced emission(AIE),crystallization induced emission(CIE)and polymorphism-dependent emission(PDE).Two single crystals of 3.1 and three single crystals of 3a were obtained by evaporation from different solvents.The data of single crystals were analyzed in detail.It was observed that the dihedral angle between phenoxazine and benzene is essential for electronic communication between electron donor and electron acceptor in one molecule.The larger it is,the more blue-shifted emission it presents.It is also worthwhile to note that a loosely packing mode,with a larger cell volume and lower cell density,is easier for a crystal to change morphology and to show mechanochromic fluorescence under pressure.3)Application of 3-amino-fluorene-2,4-dicarbonitriIe derivatives in organic photocatalysisA series of 3-amino-fluorene-2,4-dicarbonitriles synthesized previously were applied to the decarboxylative aryl coupling reaction of a-amino acids with aryl nitriles as pure-organic photocatalysts.Among them,3-Amino-1-(4-carbazol-9-yl-phenyl)-9H-fluorene-2,4-dicarbonitrile(2a)achieved the best catalytic efficiency.Significant substrate scope is observed with respect to both the carboxylic acid and arene components.This method offers rapid entry to prevalent benzylic amine architectures from easily available a-amino acid or a-hydroxy acid precursors. |
PDF Full Text Request