Achieving Robust Phosphorescence Supramolecular Polymeric Hydrogels by Green In Situ Iodoisoquinolinium Binary Copolymerization

Abstract The exploration of phosphorescence supramolecular soft materials with both sufficient mechanical and photophysical properties is crucial for their practical optoelectronic applications. Herein, robust phosphorescence supramolecular hydrogels are conveniently constructed by green one‐pot copolymerization of monoalkene‐functionalized iodoisoquinolinium derivatives (G), exfoliated Laponite (LP) nanosheets, and acrylamide (AAm) monomers in aqueous solution. Compared with the G molecule exhibiting single fluorescence emission at 454 nm, the electrostatically driven co‐assembly of G with complementary negatively charged LP not only induces an emerging room‐temperature phosphorescence (RTP) peak centered on 547 nm but also creates polymerizable noncovalent precursor crosslinkers, which can be further covalently thermopolymerized with AAm into polymeric RTP hydrogels. Owing to the synergistic dual noncovalent and covalent cross‐linkings, the synthetic hydrogels possess high mechanical strength, rapid self‐healing ability, high transparency, as well as improved phosphorescence performance even tolerant to high temperatures. Fascinatingly, efficient long‐lived red‐shifted emissions up to 777 nm are readily achieved by incorporating ultralow content (≈0.5%) of acceptors into hydrogels via a delayed sensitization strategy. Ultimately, the potential multi‐channel imaging applications of these hydrogels are realized in living HeLa cells, which not only contributes an effective strategy for preparing advanced phosphorescent soft materials but also points to a new direction for exploring their biotechnological applications.