Photochromic porous organic crystals constructed by the self-assembly of triarylethylene derivatives

Porous organic crystals have shown promising applications in fields such as separation, storage, catalysis and drug delivery, and the design and synthesis of photoresponsive materials with modulated properties represents a hot topic. In this work, a new photochromic porous crystal, namely TrPEF2-IPA, has been successfully developed via the self-assembly of a triarylethylene derivative. Notably, TrPEF2-IPA shows fast-response photochromic behaviour derived from the photoisomerisation of the triphenylethylene units with excellent fatigue resistance and repeatability under alternate irradiation by ultraviolet and visible light. Crystallographic studies and theoretical calculations further reveal that the three-dimensional structure of the porous self-assembled crystal is stabilised by hydrogen bonding and non-covalent interactions. The porous crystals can further be applied in photoswitchable patterning, multiple anti-counterfeiting and optical storage, thereby providing a promising strategy for the design of photoresponsive functional materials.