Metal–Ligand Dynamic Photopolymer Networks: Coordination State, Stimulus Response, Toughening and Reversibility

Metal-ligand coordination provides a reversible crosslinking mechanism whose strength and exchange rate can be tuned through metal identity, ligand field, stoichiometry and local environment. In photopolymer networks this enables stress dissipation, thermally assisted healing and post- print response without relying solely on covalent bond exchange. The central engineering challenge is state control: the same coordination chemistry that supports repair can also introduce creep, humidity sensitivity, ion migration, colour or optical attenuation, and competition between metal-ligand exchange and permanent covalent constraints. Recent DLP-printed metallopolymer studies demonstrate self-healing complex structures using zinc- and nickel-based coordination motifs while retaining overall geometry under selected healing conditions. Broader dynamic metal-ligand literature shows that multiphase architecture and ligand-to-metal ratio strongly affect mechanics and recovery. This review proposes a qualification framework that treats coordination state, activation temperature, environmental exposure, optical compatibility, creep, recovery efficiency and retained geometry as coupled variables rather than independent material properties.

ER-319 · Version 0.5.