Phosphorescent emitters

摘要

Compounds including a ligand with a dibenzo-fused 5-membered ring substituent are provided. In particular, the compounds may be iridium complexes including imidazole coordinated to the dibenzo-substituted ligand. The dibenzo-fused 5-membered ring moiety of the ligand may be twisted or minimally twisted out of plane with respect to the rest of the ligand structure. The compound may be used in organic light emitting devices, particularly as emitting dopants in blue devices. Devices comprising the compounds may demonstrate improved stability while maintaining excellent color.

主权项

1. A compound comprising a ligand L having the formula: wherein A is a 5-membered heterocyclic ring; wherein B is a 6-membered carbocyclic ring; wherein RB and RD represent mono, di, tri, or tetra substitutions; wherein RA represents mono or di substitution; wherein RA, RB, and RD are independently selected from hydrogen, halogen, alkyl, alkoxy, amino, alkenyl, alkynyl, aryl and heteroaryl; wherein RA, RB, and RD are optionally fused; wherein X is selected from the group consisting of NR, O, and S; wherein R is aryl or alkyl; wherein RC represents two identical substituents with the two substituents having a meta relationship to each other; wherein at least one RC is ortho to a carbon bonded to ring A; wherein the RC substituents are selected from cyclic alkyl and branched alkyl; wherein each RC has 3 or more carbon atoms; and wherein the ligand L is coordinated to a metal M having an atomic number greater than 40.