A compound comprising a first ligand LA of Formula I,




is provided. In Formula I, rings A and B are 5- or 6-membered ring; K1 and K2 are each independently selected from the group consisting of a direct bond, O, S, N(Rα), P(Rα), B(Rα), C(Rα)(Rβ), and Si(Rα)(Rβ); Z1, Z2, X1 and X2 are C or N; Y1*, Y2*, Y1*, Y4*, and Y5* are selected from a variety of moieties; n is 0 or 1; Y5* is bonded directly to X2 when n is 0; each Ra, Rβ, R, R′, R1, R2, RA, and RB is hydrogen or a substituent; each independently represents a single bond or double bond in a Lewis structure; and LA is coordinated to a metal M, which may be coordinated to other ligands Formulations, OLEDs, and consumer products containing the compound are also provided.