Single‐Molecule White‐Light Emission Based on the ESIPT Mechanism

ABSTRACT This work presents the design of a novel Schiff‐base fluorescent molecule PR, which exhibits excited‐state intramolecular proton transfer (ESIPT). It is demonstrated that PR emits white light at a concentration of 1 × 10 −5 mol/L but shows aggregation‐caused quenching (ACQ) at higher concentrations. Moreover, this molecule exhibits distinct color changes in solvents of varying polarity and demonstrates pronounced pH‐responsive behavior. Finally, a white light PVA/(1 × 10 −5 mol/L PR) gel was fabricated using polyvinyl alcohol (PVA) as a carrier. This PVA/PR gel system has been successfully utilized as a writing medium for information encryption and protection, showcasing great application potential in the field of single‐molecule white‐light‐emitting materials.