New Molecular Photoswitch Based on the Conformational Transition of Phenothiazine Derivatives and Corresponding Triplet Emission Properties.

Molecular photoswitch research has drawn much attention in the last century owing to its great potential in the development of smart materials. However, photoswitches suitable for constructing light-responsive luminescent materials remain limited, especially those involving triplet-state phosphorescence. Herein, we designed a novel molecular photoswitch based on the conformation transition of phenothiazine derivatives, minimizing steric hindrance (-CH > -Cl > -F) to regulate the conformation transition process while introducing a cyanobenzene acceptor to promote phosphorescence emission potential. When they were doped into a polymer matrix, varying photoswitch rates were achieved by incorporating different steric hindrance groups into phenothiazine or cyanobenzene groups, accompanied by photoresponsive room-temperature phosphorescence. This study is expected to greatly expand the diversity and applications of organic photoswitch molecules.