Synthesis of efficient blue and red light emitting phenanthroline derivatives containing both hole and electron transporting properties

Two phenanthroline derivatives containing a hole transporting triphenylamine and an electron transporting 1,3,4-oxadiazole unit have been prepared with high yield. UV-vis absorption and fluorescence measurement indicated they are high efficient light-emitting materials. The compounds are 6-(5-(4-N,N'-diphenylaminophenyl)-1,3,4-oxadiazol-2-yl) quinoxalino[2,3-f] phenanthroline (9, lambda(max)=635nm, 40% quantum yield), and 1-ethyl-2-(4-(5-(4-N,N'-diphenylaminophenyl)-1,3,4-oxadiazol-2-yl)phenyl)imidazo[4,5-f]phenanthroline (14, lambda(max)=461 nm, 78% quantum yield). Preliminary study on electroluminescence for the two fluorescent dyes prepared from vacuum evaporation resulted in blue and red light emitting organic light emitting diodes (OLED). (C) 2004 Elsevier Ltd. All rights reserved.