| abstract |
An electroluminescent device, including a space-apart anode and cathode; and an emissive layer disposed between the space-apart anode and cathode and including an organic compound having a complex fluorene structure represented by one of the above formulas: (I); (II); or (III) wherein: X1, X2, X3 and X4 are individually the same or different and include a moiety containing CH or N; R1, R2, R3 and R4 are substituents each being individually hydrogen, or alkyl, or alkenyl, or alkynyl, or alkoxy of from to 1 to 40 carbon atoms; aryl or substituted aryl of from 6 to 60 carbon atoms; or heteroaryl or substituted heteroaryl of from 4 to 60 carbons; of F, Cl, or Br; or a cyano group; or a nitro group; or R3 or R4 or both are groups that form fused aromatic or heteroaromatic rings. |