Triarylamine polymers of bridged phenylenes by (N-heterocyclic carbene)-palladium catalysed C–N coupling

A library of triarylamine copolymers with 2,7-fluorene, 3,7-dibenzo[b,d]thiophene and 2,7-carbazole units incorporated in the polymer backbone is reported. The polymers were synthesised by using C-N coupling of anilines and dibromoarenes, catalysed by N-heterocyclic carbene complexes of palladium. The properties of the polymers were tuned by changing the nature of the fused ring structure and the substitution of the pendant benzene of the arylamine. The use of these polymers as the charge transporting layer of an OFET is demonstrated with the highest mobility found for polymers derived from 2,7-dibromo-9,9'-dioctylfluorene and 4-methoxy-2-methylaniline.