Synthesis of thiophene–pyrrole mixed oligomers end-capped with hexyl group for field-effect transistors

Mixed thiophene–N-methylpyrrole oligomers composed of the five and six heterocycles and hexyl substituents at both ends were synthesized, and their structural, electronic, and field-effect properties were investigated. These oligomers behaved as good p-type semiconductors on FET devices and the mixed hexamer with a nearly linear structure showed higher hole mobility (5.3 × 10−2 cm2 V−1 s−1) than that of the pentamer with a banana-shaped structure.