Heteroacenes for Organic Field-Effect Transistors

Significance

The authors report a two-step synthesis of heteroacene 1 in moderate yield. The synthesis consists of a Stille coupling between a methylsulfinyl-derivatized aryl dibromide and a alkylated thiophene precursor. An intramolecular cyclization is carried out in the presence of triflic acid. The resulting five-ring-fused pentacene analogues were used as organic semiconductors in bottom-gate, top-contact organic field-effect transistor devices. The authors report hole mobilities of up to 1.7 cm^²V^-¹s^-¹ and on/off ratios of 10⁷.