Universal Display Corporation
ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES

Abstract:

A compound having a ligand L.sub.A of Formula I, ##STR00001## is disclosed. In Formula I, ring B is a 5-membered or 6-membered ring; K is a direct bond, O, or S; X is O, S, Se, NR, CRR', SiRR', or GeRR'; R.sup.1 and R.sup.2 are each independently selected from a variety of substituents; each R, R', R.sup.A, and R.sup.B is independently hydrogen or a substituent; L.sub.A is coordinated to a metal M selected from Os, Ir, Pd, Pt, Cu, Ag, or Au by the dashed lines; any two adjacent of R.sup.1, R.sup.2, R, R', R.sup.A, or R.sup.B can be joined or fused to form a ring, with the proviso that when ring B is a 6-membered ring, two R.sup.B substituents are not joined to form a fused 6-membered aromatic ring. Organic light emitting devices, consumer products, formulations, and chemical structures containing the compounds are also disclosed.