Triazolinedione chemistry: a versatile toolbox for advanced functional materials.

Triazolinedione (TAD) chemistry has established itself as a leading click platform with outstanding kinetics' high chemoselectivity' catalyst-free reaction conditions' and compatibility with a range of functional groups. These characteristics have enabled TAD chemistry to be used for constructing advanced functional materials beyond its initial application in polymer modification. This review summarizes the key TAD reaction pathways' including irreversible click reactions' reversible reactions and applications in advanced functional group transformation, with a focus on materials applications. Recent advancements in TAD-enabled functional materials' including smart and dynamic materials' porous polymers' biomaterials' functional nanomaterials' elastomers and rubbers' surface engineering and coatings' as well as electrochemical interface engineering' are also discussed and summarized. Particular attention is paid to the relationship between TAD reaction mechanisms and the resulting material properties, illustrating how rapid, selective, and reversible bond formation enables multifunctionality, responsiveness, and precise molecular engineering. Finally, current challenges, emerging opportunities, and future perspectives are discussed to develop TAD chemistry as a powerful platform for the next generation of functional materials.