Blue-emitting anthracenes with end-capping diarylamines

A new series of 2-tert-butyl-9,10-bis(bromoaryl)anthracenes have been synthesized from 2-tert-butyl-9,10-anthraquinone. Palladium-catalyzed C-N bond formation between these bromo compounds and diarylamines provides stable 2-tert-butyl-9,10-diarylanthracenes containing two peripheral diarylamines (anth). They possess high thermal decomposition temperature (T-d > 450 degreesC) and form a stable glass (T-g > 130 degreesC). Furthermore, they are fluorescent in the blue region with moderate to good quantum efficiencies. Two types of light-emitting diodes (LED) were constructed from anth, (I) ITO/anth/TPBnlg:Ag and (II) ITO/anth/Alq(3)/Mg:Ag, where TPBI and Alq(3) are 1,3,5-tris(M-phenylbenzimidazol-2-yl)benzene and tris(8-hydroxyquinolinato)aluminum, respectively. In type I devices, the anth function as the hole-transporting and emitting material. In type II devices, emission from Alq3 is observed. Several blue-light-emitting type I devices exhibit good maximum brightness and physical performance. The relation between the energy levels of the anth and the performance of the light-emitting diode is discussed.