Constructing an auto triplet excitons supply system for photogenerated radicals in the solid state

Organic radical materials have attracted significant attention for their unique photophysical properties and potential applications. Herein, we propose an auto triplet excitons supply system to generate radicals through the photoinduced electron transfer process for practical applications. By manipulating the n-π* transition and p-π conjugation, we achieve enhanced photoactivated phosphorescence coupled with rapid radical generation rates in the methoxy-substituted naphthylamine derivative (OCH3-DNaAPh) and fluorine-substituted naphthylamine derivative (F-DNaAPh), confirming the crucial role of the long-lived excitons supply in generating stable radicals upon UV irradiation. OCH3-DNaAPh is thus selected for implementing quantitative monitoring and an automated alarm system for UV radiation, featuring a two-stage risk warning model for excessive UV exposure. Furthermore, it acts as the photoinitiator for the polymerization of methyl methacrylate under UV irradiation, further enhancing phosphorescence emission above 473 K. The study describes a method to generate organic photogenerated radicals in the solid state, broadening their scope of practical applications.