First examples of alkenyl pyridines as organic ligands for phosphorescent iridium complexes

The first successful synthesis of iridium complexes {(PEP)(2) Ir(acac), (NEP)(2)Ir(acac), (PETP)(2)Ir(acac), (MPEP)(2)Ir(acac), and (PP)(2)Ir(acac)} (see Figure) using an olefin-tethered pyridine ring is described. The electroluminescent devices prepared using these iridium complexes as dopant emitters showed very high brightness and efficiencies.