Dragon-Boat-Type Heptathienoacenes: Synthesis, Structures, and Their Applications in OFETs.

A novel synthetic strategy for efficient construction of dragon-boat-type heptathienoacenes ( DBHT s) via the α-β position carbon-carbon cross-coupling between two dithienothiophenes is employed. Their crystal structures are confirmed by X-ray single-crystal analysis. The first thin film FET devices of heptathienoacenes are fabricated using OTS-treated SiO 2 /Si substrates, in which DBHT-5 -based devices exhibit an unprecedented highest hole mobility value of 1.15 cm 2 V -1 s -1 and on/off ratios over 10 6 with a threshold voltage of 0 V.