Organic crystals are essential in modern technology like optoelectronics, solar cells, etc., but are generally considered as brittle and inelastic. Polymers, hydrogels, etc. on the other hand are already used in smart materials due to their mechanical flexibility but suffer from long-range structural order. Therefore, organic molecular crystals equipped with flexible deformation capabilities can bridge hard (in)organic and soft polymeric materials. In this regard, photoluminescent organic crystalline crystals, which alter their emission properties by adopting different crystal shapes under external mechanical stress, are of extreme relevance in developing of all-organic mechanosensors, optical waveguides etc.

Here, we aim to fabricate/enhance mechanical flexibility (elastic/plastic) and photoluminescence properties of pure organic crystalline materials through cocrystal engineering and rationalize the underlying mechanisms at the supramolecular level.