Compounds having the structure of Formula M(LA)x(LB)y and Formula III, are disclosed. In Formula M(LA)x(LB)y, Ligand LA is and ligand LB is a mono anionic bidentate ligand. In these compounds, metal M has an atomic number greater than 40; x is 1, 2, or 3; y is 0, 1, or 2; x+y is the oxidation state of metal M; L11 represents a linking group selected from alkyl, cycloalkyl, aryl, and heteroaryl; L12 represents a linking group selected from NR15 and PR15; each R1, R2, R3, R4, R5, R6, R11, R12, R13, R14, and R15 is independently selected from a group of substituents, wherein any adjacent substituents are optionally joined to form a fused or unfused ring; and LA and LB are optionally joined to form a ligand that is at least tetradentate. Formulations and devices, such as OLEDs, that include the compound of Formula M(LA)x(LB)y(LC)z are also described.