Patent ID: 8507896

Claim:
A composition comprising a compound of the formula R 1 (CR 3 ═CR 4 ) n Ar(CR 4 ═CR 3 ) n R 2 wherein: n is 0 or 1; Ar represents aryl or heteroaryl having 1-5 aromatic rings which is optionally chain or fused or a combination of chain and fused, which is optionally substituted with alkoxy, fluoro, fluoroalkyl or cyano and which in the case of a 5-membered ring nitrogen heteroatom is optionally N-substituted with aryl or substituted aryl optionally further substituted with alkoxy, fluoro, fluoroalkyl or cyano; R 1 and R 2 independently represent aryl or nitrogen, oxygen or sulphur-containing heteroaryl having two to four fused aromatic rings one of which is optionally a 5-membered and optionally substituted by aryl or heteroaryl having 1-5 chain or fused aromatic rings which is optionally further substituted with alkoxy, fluoro, fluoroalkyl or cyano; and R 3 and R 4 independently represent hydrogen, methyl, ethyl or benzyl, and a dopant.