Conjugated microporous polymers promote photoswitching in the solid-state

Photoswitches are attractive for various applications due to the fast, efficient, and reversible isomerization under controlling of light and heat. However, it's difficult to achieve reliable photoisomerization in the solid state because of the strong intermolecular aggregation, which is originated from the planar molecular structure and conjugated nature of photoswitches. Improving molecular distribution is a general and important method for promoting the isomerization properties in the solid state. This review presents recent progress for fabricating solid state photoresponsive materials based on the periodically distributed nanoporous structure of metal-organic frameworks (MOFs). Photoswitches including azobenzene, spiropyran, diarylethene, and donor-acceptor Stenhouse adduct have been reported to be integrated into the nanopores of MOFs as part of a backbone, linker, and guest. The potential to control photoisomerization by varying the physicochemical environment in the nanopores of MOFs was discussed.