Imidazolium-based covalent organic cages: from construction to functions

Abstract Imidazolium-based covalent organic cages (COCs) have recently emerged as versatile (supra)molecular platforms that unite ionic functionality with structural precision. Their modular architectures and tunable cavities enable diverse applications ranging from anion recognition and iodine capture to fluorescence sensing, antibacterial activity, and catalysis. This mini review summarizes advances in the synthesis and functional development of imidazolium-based COCs, with particular emphasis on strategies such as direct quaternization cyclization, metal-templated photochemical cycloaddition, and dynamic imine condensation, as well as insights into their structure–function relationships. The article concludes with perspectives on improving synthetic efficiency, optimizing cavity design, and expanding biomedical and environmental applications.