Benzo[a]aceanthrylene Derivatives for Red-Emitting Electroluminescent Materials

Benzo[a]aceanthrylene-cored compounds (acen) encapsulated with two peripheral arylamines have been synthesized from 1-chloro-anthraquinone by the method of Dehaen, palladium-catalyzed aromatic C−N coupling reactions, and cyclization of diphenylanthracene. These compounds have high thermal stability, and they readily form glass with high glass-transition temperatures. The emission colors of the compounds vary from orange to red. Two quasi-reversible one-electron oxidation waves were observed for the two peripheral amines which are in different chemical environments. The new materials can be deposited as a pure thin film. Pure red-emitting devices were fabricated using acen as both hole-transporting and emitting materials and 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI) as the electron-transporting materials, or using Alq3 (tris(8-hydroxyquinoline)aluminum) as the electron-transporting materials interposing a hole-blocking BCP layer between acen and Alq3.