| abstract |
Compounds having a metal M complexed to a ligand L containing a substituted imidazole carbene group, which is represented Formula (I), below: n nwherein ring B is a 5-member aromatic heterocyclic ring containing at least one heteroatom selected from the group consisting of N, O, and S; wherein ring A is a 5-membered or 6-membered carbocyclic or heterocyclic ring; wherein R A represents mono, di, tri, tetra substitutions or no substitution; wherein R 1 represents mono, di, or tri substitution or no substitution; wherein each R A , R 1 and R 2 is independently selected from various possible substituents; wherein Z 1 is nitrogen or carbon; and wherein the ligand is optionally linked with other ligands to comprise a tridentate, tetradentate, pentadentate or hexadentate ligand. Devices, such as organic light emitting devices (OLEDs) that comprise such compounds are also provided. |