An S-shaped thienoacene semiconductor forming unique cruciform lamellar packing via a 2D interaction network of π-stacking and chalcogen bonding

A crooked S-shaped thienoacene, S-B2T4, consisting of four fused thiophene rings and two benzene rings can self-organize into a unique cruciform lamellar packing. In each lamellar layer, adjacent S-B2T4 molecules are orthogonally arranged to form a cruciform molecular array. The extended 2D interaction network via π-stacking and chalcogen bonding is crucial for stabilizing such molecular packing. Effective electronic couplings in the S-B2T4 molecular array lead to high hole mobilities of up to 1.5 cm2 V−1 s−1 in solution-processed thin-film transistors.