Synthesis, Properties, and OFET Characteristics of 5,5′-Di(2-azulenyl)-2,2′-bithiophene (DAzBT) and 2,5-Di(2-azulenyl)-thieno[3,2-b]thiophene (DAzTT)

Two azulene-based π-conjugated systems, 5,5′-di(2-azulenyl)-2,2′-bithiophene and 2,5-di(2-azulenyl)-thieno[3,2-b]thiophene, were constructed via Suzuki–Miyaura cross-coupling reactions. The crystal structures of both revealed an edge-to-face orientation in a well-defined herringbone packing. The molecules stood nearly perpendicular to the substrate in the film form, with features of an organic field-effect transistor at hole mobilities of up to 5.0 × 10–2 cm2 V–1 s–1.