| abstract |
The present application relates to organic electroluminescent materials and devices. A compound is disclosed comprising a first ligand LA having a formula selected from: and In said formula, rings B and C are 5-membered or 6-membered aromatic or heteroaromatic rings; Z 1 , Z 2 , X 1 , X 2 , X 3 , X 4 , X 5 and X 6 are each C or N, but when X 1 , X 2 , X 3 or X 4 forms a direct bond with Z 2 it is C; Y is selected from CRR', NR', O, S and Se; R, R', R A , RB , RC , and RD are each selected from a variety of substituents; the ligand LA is coordinated to the metal M , and optionally to other ligands, through dashed lines. Organic light emitting devices and consumer products containing the compounds are also disclosed. |