A series of novel arylvinyl-substituted phenanthroline derivatives have been synthesized and their applications as electron-transporting materials in organic light-emitting diodes (OLED's) have been investigated One particular derivative, namely, 2,9-bis(2-thiophen-2-ylvinyl)[1,10]phenanthroline shows significantly lower operating voltage than tris(8-quino-linolato)aluminum(III) (Alq(3)) and substantially higher lifetime than bathophenanthroline (BPhen)