Two novel organic compounds substituted with hole transporting arylamine and electron transporting 1,3,4-oxadiazole moieties have been designed and synthesized using a facile multistep reactions with high yield. The compounds are N-{4-[5-(2-phenylquinolin-4-yl)-1,3,4-oxadiazol-2-yl]-phenyl}-N'-phenyl- N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (TPDOPQ) and N,N'-bis{4-[5-(2-phenylquinolin-4-yl)-1,3,4- oxadiazol-2-yl]-phenyl}-N,N'-diphenyl-1,1'-diphenyl-4,4'-diamine [TPD(OPQ)₂]. These compounds emit intensive green light with high fluorescence quantum yields of 33%～48% under 450 nm light excitation. Cyclic voltammetry measurement results imply that these two compounds have both good hole-transporting and good electron-transporting properties, and hole-transporting is predominant. TG analysis showed high thermal stability of the compounds and vacuum-coating experiments confirmed the formation of homologous films from these compounds. All the results indicate that the synthesized compounds are potentially good candidates as bipolar (hole-transporting/electron-transporting) and emitting materials for fabrication of organic light-emitting diodes.

Key words: organic small molecule, hole-transporting, electron-transporting, luminescence