The invention provides emissive materials and organic light emitting devices using the emissive materials in an emissive layer disposed between and electrically connected to an anode and a cathode. The emissive materials include compounds with the following structure: wherein at least one of R8 to R14 is phenyl or substituted phenyl, and/or at least two of R8 to R14 that are adjacent are part of a fluorenyl group. The emissive materials have enhanced electroluminescent efficiency and improved lifetime when incorporated into light emitting devices.