Universal Display Corporation
Organic electroluminescent materials and devices

Abstract:

A compound of Formula (L.sub.A).sub.n-M-(L.sub.C).sub.m, wherein the ligand L.sub.A is of Formula I, and the ligand L.sub.C is selected from Formula I that is different than ligand L.sub.A, a monoanionic bidentate ligand, or a monoanionic monodentate ligand. M is a metal; and n is 1 or 2, and m is 0, 1 or 2. ##STR00001## Ring A is a 5-membered or 6-membered heteroaryl ring, which is bonded to Ring B; Z is selected from O or S; Z.sup.1 is selected from a carbene C or N; and Z.sup.2 is selected from C or N. Moreover, two adjacent ring carbons of Ring B will form a group of formula D, wherein * represents the point of attachment to the two adjacent ring carbons, ##STR00002## Formula D, wherein X is selected from NR.sup.N, O, S, or Se; and R.sup.N is selected from the group consisting of hydrogen, deuterium, alkyl, cycloalkyl, heteroalkyl, aryl, heteroaryl, and combinations thereof; and Y.sup.1, Y.sup.2, Y.sup.3, and Y.sup.4 are independently CR.sup.Y1, CR.sup.Y2, CR.sup.Y3, and CR.sup.Y4, respectively, or N, and Ring D has no more than two nitrogen ring atoms. An OLED that includes a compound of the Formula I above in an organic layer is also described.