Full‐Color Tunability Room Temperature Phosphorescence from Inorganic Crystal Frameworks

Abstract Room temperature afterglow (RTA) materials have aroused prodigious research interests owing to their unique long‐life luminescent properties. However, it is rare for RTA materials to be reported with full‐color afterglow emission. Herein, a universal strategy is designed to activate full‐color tunability RTA based on phenylboronic acid derivatives (BOH) and boric acid (BA) via an ingenious solvent‐free solid‐phase heating. As the conjugation degrees of aromatic groups of the guest molecule expanded, the BOH/BA composites showed tunable afterglow colors ranging from blue to red after ultraviolet (UV) irradiation. This strategy is to firmly anchor the guest molecule in a rigid framework of the inorganic metaboric acid matrix by abundant hydrogen‐bonding interactions between the host and guest, suppressing molecular motion and promoting the intersystem crossing (ISC) rate between the singlet and triplet excited states for enhanced afterglow emission. In addition, through mixing in multiple guest molecules into BA simultaneously, the obtained composite can be modulated in a wide excitation range from blue to red. This fascinating study provides a simple and universal method to fabricate full‐color tunability RTA composites, making them a promising candidate for applications in advanced information security and multi‐level encryption.