A compound having a structure of Formula I In Formula I, M is Pd or Pt; each of X1 to X12 is independently C or N; ring A is a 5-membered or 6-membered ring; K1 and K2 are selected from a direct bond, O, S, and NR; L1 is an organic linker; Y1 is selected from O, S, BR, PR, Se and NRY; each R, RY, RA, RB, RC, and RD is hydrogen or a substituent; and any two substituents can be joined or fused to form a ring. Further provided are OLEDs and related consumer products that utilize these compounds.