Hydrazone‐Based AIEgens with Photofluorochromic Ability for Rewritable, Intensity‐Variable, and High‐Resolution Photopattern

Abstract Photoswitches with multiple fluorescence states known as photofluorochromism upon photo‐induced isomerization show practical applications in information storage, anticounterfeiting, and sensors. However, it is still challenging to realize rapid isomerization, efficient fluorescence, and gradient signal output simultaneously. Herein, by incorporating luminogenic units with aggregation‐induced emission (AIE) features into photo‐responsive hydrazone, a series of novel photofluorochromic AIE compounds are developed. These newly designed compounds exhibit quantum yields of up to 38.4% and could undergo reversible and swift photo‐isomerization upon 450/365 nm irradiation. Accordingly, the fabricated photopatterns based on them are utilized as quantitatively described images for information storage, which show excellent rewritability and intensity‐variable fluorescence with a high resolution of 10 µm. This work provides a new strategy to develop intelligent photopattern systems with continuous gradient fluorescence for information storage and cybernetics.