Engineering elasticity in a brittle photoluminescent organic semiconductor via template-directed cocrystallization

We introduce a cocrystallization-based strategy to impart mechanical compliance to otherwise brittle organic semiconductor (OSC) crystals. While 9,10-bis((E)-2-(pyridin-3-yl)vinyl)anthracene (BP3VA) forms brittle crystals as a pure component, it becomes elastic upon cocrystallization with a series of trihalophenols (3X-ph-OH, X = Br, Cl, I). The structural buffering elements of the trihalophenols, comprising π-stacked architectures stabilized by dispersive [X⋯X] and [C-H⋯X] contacts, are effectively transferred from their single-component crystal structures into BP3VA cocrystals via "large synthons". The structural buffer transfer results in mechanically interlocked supramolecular architectures that exhibit elasticity while preserving intrinsic phololuminescence of the parent OSC. We envisage cocrystallization as an effective platform for designing elastic functional materials based on OSCs.