Organic high-temperature afterglow with acid/base-responsive properties

Multi-stimuli-responsive afterglow materials have demonstrated broad applications in information encryption, anticounterfeiting, and sensors for dynamic and time-resolved emission toward various stimulus sources. Herein, through combining room-temperature phosphorescence (RTP) units with phenolic hydroxyl groups, high-temperature afterglow and acid/base-responsive properties were achieved by the formation of strong hydrogen bonding in the crystalline states and the reactivity of active hydrogen, respectively. Accordingly, the dynamic blue–green afterglow can be visible to the naked eye even at 423 K, the “turn-off” response toward HCl, and largely enhanced afterglow properties by NH₃ fumigation have been realized through the modulation of the molecular structures and aggregated states. This provided a convenient and efficient strategy to achieve multi-stimuli-responsive afterglow by the full utilization of hydroxyl groups as functional moieties.