Tetrazine-based metal-organic frameworks

Metal-organic frameworks (MOFs), featuring tailor-made structural topology and porosity (aperture size and geometry) by judicious choices of inorganic second building units and organic ligands, hold great promises for multitudinous applications including gas storage, separation, chemical sensing, etc. To efficiently broaden their applications, novel frameworks can be designed and synthesized by additionally functionalizing MOFs via reasonable modification of the building blocks (organic bridging ligands and inorganic metal clusters/ions) of MOFs. Tetrazines, particularly 1,2,4,5-tetrazines (also referred to as s-tetrazines), have gained significant attention in the field of coordination chemistry due to their distinctive features, for instance, the electron-deficient nature and potential post-synthetic modification through the well-recognized inverse electron-demand Diels-Alder (iEDDA) cycloaddition. Although tremendous progresses have been made so far toward the synthesis and application of tetrazine-based MOFs for small molecules adsorption, photocatalysis, battery fabrication, and chemical sensing, a comprehensive review summarizing the latest progress of tetrazine-based coordination chemistry and their applications is absent. Herein, we summarize comprehensively the latest progress on the design and synthesis of tetrazine based MOFs and their applications in the aspects of adsorption, sensing, battery, and catalysis. The surface chemistry and structure characteristics were carefully associated with the relevant applications. Finally, challenges and future prospects about long-term development and potentially practical application of tetrazine-based MOFs are pointed out.