Unexpected Polymerization-Induced Luminescence in Deep Eutectic Solvent (DES)-Based Polymer

Here, a polymerizable type-IV deep eutectic solvent (DES) is synthesized via the coordination reaction between acrylamide and SbCl 3 , and for the first time it is demonstrated that the resultant type-IV DES-based polymers can exhibit luminescence after polymerization due to the efficient Sb-ligand and ligand–ligand charge transfer. Notably, the quantum yield of Sb-ligand charge transfer emission can be tuned with the controllable reversible addition-fragmentation chain transfer (raft) polymerization of acrylamide, reaching up to 15.32%. As a proof-of-concept application, the polymerizable DES is utilized as fluorescent anti-counterfeit ink, successfully realizing the fluorescence encryption.