C-H⋯π interaction-modulated solid-state packing and carrier mobility in thienyl and thieno[3,2-b]thienyl end-capped distyrylarylene derivatives

Research on structure-property relationships in distyrylarylene derivatives is far behind their wide applications in optoelectronic devices due to the absence of crystal structure information. Herein, the single crystals of 4,4′-bis(2-thienylvinyl)biphenyl (1) and 4,4′-bis(2-thieno[3,2-b] thienylvinyl)biphenyl (2) were successfully grown by the vapor transport method. Both molecules adopt the typical herringbone packing motif. However, the intermolecular C-H⋯π interaction in compound 2 is much stronger than that in compound 1. The correlations of interchain interaction with film morphology, optical and electronic properties were studied. Compound 2 formed higher crystalline films with (001) and (111) orientations. The organic field-effect transistor properties of both materials were investigated. Compound 2 showed better performance with a hole mobility higher than 0.01 cm ²V^-1s^-1 and an on/off current ratio over 10⁶. These results reveal that the intensity of C-H⋯π interactions can exert dramatic influences on the optical and electronic properties of distyrylarylene-based materials.