Blue phosphorescent imidazophenanthridine materials

The present invention describes compounds containing phosphorescent metal complexes, which include cyclometalated imidazo [1,2-f] morphidine and diimidazo [1,2-a: 1 ', 2'- c] Quinazoline ligand or its isoelectronic or benzocyclized analogue. Organic light-emitting devices containing these compounds are also described.