Compounds comprising the formula L1L2MX wherein L1, L2, and X are distinct bidentate ligands that form an octahedral complex on the metal M, wherein M is a metal with an atomic weight greater than 40. Compounds of this formula are sublimated more facilely than octahedral metal complexes where L1, L2, and X are not distinct bidentate ligands. Organic light emitting devices are also described wherein the emissive layer may comprise a host material containing an emissive molecule of formula L1L2MX, which molecule is adapted to luminesce when a voltage is applied across the heterostructure, and the emissive molecule is selected from the group of phosphorescent organometallic complexes, including iridium complexes of the formula L1L2IrX wherein L1, L2, and X are distinct bidentate ligands.