| abstract |
A compound having a formula M(L A ) x (L B ) y (L C ) z , where ligand L A is n n n n n n n n n n ligand L B is n n n n n n n n n n and ligand L C is n n n n n n n n n n is disclosed. In formula M(L A ) x (L B ) y (L C ) z , M is a metal having an atomic number greater than 40; x is 1 or 2; A 1 -A 8 are carbon or nitrogen; ring B is bonded to ring A through a C—C bond; M is bonded to ring A through a M-C bond; X is O, S, Se, CRR′, or NR 1 ; rings C and D are each independently a 5 or 6-membered carbocyclic or heterocyclic ring; at least one R 4 is a five-membered or six-membered heterocyclic ring which can be further substituted by R E ; each R substituent is independently selected from a variety of moieties; and any adjacent R substitutents are optionally joined to form a ring. Formulations and devices, such as an OLEDs, that include the compound of formula M(L A )(L B )(L C ) z are also described. |