Subphthalocyanine semiconducting cocrystals with efficient super-exchange coupling

Abstract

Organic cocrystals have attracted widespread research attention due to their unique properties. However, the development of crystal engineering is relatively slow because of the difficulty in designing the molecular structures and controlling the intermolecular interactions. Here, we report a subphthalocyanine (SubPc) cocrystal (SubPc-12H-12F) through preciously regulating hydrogen bonds and donor–acceptor interactions. The cocrystal forms a perfect one-dimensional columnar assembly and shows an almost identical packing mode with a one-component single crystal SubPc-6F(β), which provides an ideal example to study the super-exchange coupling in cocrystals. The SubPc-12H-12F cocrystal exhibits ambipolar transport properties with an improved hole mobility of 0.019 cm² V⁻¹ s⁻¹ by two orders of magnitude compared with SubPc-6F(β). The cocrystals of SubPc-12H-12F exhibit the highest mobilities ever reported among SubPc derivatives and surpass the order of 10⁻² cm² V⁻¹ s⁻¹ for the first time. Theoretical calculations indicated that the super-exchange coupling in cocrystals can both increase the charge carrier mobility and expand the charge transport channels, which holds the potential to further predictions for high-performance cocrystals.