Fluorogenic Dynamic Covalent Polymers: Ultrafast, One-Pot Synthesis, Bond Exchange Visualization, and Vitrimer-Like Functionality

This study presents a fluorogenic dynamic covalent platform based on indanone-conjugated acceptors, designed to address limitations in traditional dynamic covalent materials, including complex and time-consuming synthesis and a lack of real-time monitoring. By exploiting the orthogonal reactivity of the dual-site indanone acceptor with amines, the platform facilitates a simple one-pot synthetic route and imine bond formation with turn-on fluorescence, thus enabling in situ, real-time visualization and tracking of dynamic covalent bond exchange. The system demonstrates reversible, pH- and solvent-controlled switching between monoamine and diamine coupling, allowing for flexible polymer design in both aqueous and organic media. Leveraging this versatile platform, we achieved ultrafast polymerization to yield structurally tunable fluorescent linear polymers. This one-pot strategy overcomes the complexity of traditional methods, providing access to structurally well-defined macromolecules. Additionally, we synthesized a degradable, highly cross-linked vitrimer-like polymer that undergoes spontaneous network reorganization at elevated temperatures, without the need for catalysts or solvents during both synthesis and network reorganization, enabling efficient self-healing and thermal recyclability while maintaining mechanical properties. This integration of real-time optical monitoring, tunable environmental responsiveness, and robust macroscopic performance offers a versatile molecular toolkit for the design of smart materials with further applications.