| abstract |
A compound having the formula Ir(L A ) n (L B ) 3-n , having the structuren nof Formula I is provided. In the structure of Formula I, each of A 1 through A 8 is independently carbon or nitrogen; at least one of A 1 through A 8 is nitrogen; ring B is bonded to ring A through a C-C bond; the iridium is bonded to ring A through an Ir-C bond; X is O, S, or Se; each of R 1 through R 5 are independently selected from a variety of substituents, whichmay be linked for form a ring; n is an integer from 1 to 3; and at least one R 2 adjacent to ring C is not hydrogen. Formulations and devices, such as OLEDs, that include the first compound are also provided. |