H-shaped anthracene-based semiconducting molecules bearing a 9,10-bis((4-hexylphenyl)ethynyl)anthracene dimer

We have successfully synthesized and characterized H-shaped anthracene-based semiconducting molecules that are solution processable. They were synthesized using 9,10-bis((4-hexylphenyl)ethynyl)anthracene via the Stille coupling reaction. The two molecules not only form uniformly smooth films on large surfaces but also show better homogeneous layer formation with relatively small crystallites. The semiconducting properties of the two π-conjugated molecules, 3 and 4, were evaluated by using the molecules in organic thin-film transistors (OTFTs). As-spun films of these molecules showed fairly high charge carrier mobilities of around 0.013–0.037 cm2 V−1 s−1 (Ion/Ioff > 104–5) without additional thermal treatment. The molecule bearing a bithiophene connecting group unexpectedly showed relatively poor carrier mobility, which is attributed to a less-ordered structure and poor anisotropic arrangement of the crystallites without annealing process.