An organic light emitting device is provided. The device has an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer further comprises an emissive material having the structure: ##STR00001## wherein M is a metal having an atomic weight greater than 40; ring A is an aromatic heterocyclic or a fused aromatic heterocyclic ring with at least one nitrogen atom that is coordinated to the metal M, wherein the ring A can be optionally substituted; (X--Y) is an ancillary ligand; m is a value from 1 to the maximum number of ligands that may be attached to the metal; and m+n is the maximum number of ligands that may be attached to the metal. The emissive material itself is also provided. The emissive material may have improved efficiency and stability when incorporated into a light emitting device.