An organic light emitting device is provided. The device has an anode, a cathode, and an organic layer disposed between the anode and the cathode. The organic layer comprises an emissive material having a transition metal and two or three bidentate ligands, which may be photoactive ligands. The bidentate photoactive ligands may be bound to the transition metal through a carbon-metal bond and a nitrogen-metal bond to form a cyclometallated ring. The organic layer may have the formula LX.sub.a-(L).sub.bM, wherein X is a linking group that links two or more ligand L and M is a metal.