A compound comprising a ligand LA comprising a moiety L having a structure of Formula I is provided. In Formula I, LA coordinated to a metal M; A1 is selected from B, N, P, P═O, P═S, Al, Ga, SiR″, GeR″, and SnR″; where rings A, B, and C are 5- or 6-membered rings; Y1, Y2, and Y3 are selected from direct bonds, the metal M, and a variety of linkers; a+b+c=2 or 3; and one of a number of specific conditions is met. OLED devices, consumer products, and formulations including the compound are also provided.