Photocontrolled Noncovalent Cross-Linkers with Diversely Tunable Properties via Interchangeable Metal Cations

Noncovalently cross-linked polymer materials are widely used due to their dynamic response, self-healing, recycling, and reprocessing capabilities. Among the noncovalent cross-linkers, photocontrolled cross-linking is of great interest due to its clean and noncontact process for forming and dissociating noncovalent polymer networks. However, most of the noncovalent cross-linkers rely on predetermined binding motifs that exhibit fixed association affinities, restricting their adaptability to diverse material properties. This work introduces a new strategy for photocontrolled noncovalent cross-linking based on photomodulated metal-ligand interactions. By employing interchangeable central cations, our system introduces a modular platform for tuning cross-linking strength, enabling property diversity without altering the underlying motif. As a result, we prepared materials that demonstrate a wide range of thermal and mechanical properties depending on the choice of central cation, expanding the potential for noncovalent polymer network materials and supporting their use in various applications.