A compound of Formula I wherein M is a metal selected from Ir or Os; rings A, B, C, D, E, and F are independently a 5-membered or 6-membered aromatic ring; Z1 to Z14 are independently selected from C or N; X is selected from a direct bond, or a linker with one to ten backbone member atoms; and Y is selected from a direct bond, a linker with one to ten backbone member atoms, or is absent to provide an open hexadentate ligand. An organic electroluminescent device (OLED) that includes an anode, a cathode, and an organic layer comprising a compound of the Formula I, and a consumer product comprising the OLED.