Cyclodextrin Covalent-Organic Frameworks: Bridging Host–Guest Chemistry and Porous Materials for Diverse Applications

Cyclodextrin Covalent-Organic Frameworks (CD-COFs) represent a distinctive class of porous crystalline materials that combines the structural order and tunable porosity of covalent-organic frameworks with the host–guest recognition and chiral selectivity of cyclodextrins. This review presents an analysis of recent progress in CD-COF research with emphasis on applications already demonstrated in the literature. CD-COFs show strong performance as highly selective stationary phases for chromatographic separations, enabling resolution of positional isomers and chiral enantiomers through inclusion complexation within ordered cavities supported by a high-surface-area framework. Framework architecture also enables rapid and selective adsorption of micropollutants, perfluorinated compounds, and other persistent contaminants, pointing to use in sustainable water treatment. Studies further report roles in energy and environmental technologies that include solid-state lithium-ion conduction, carbon capture, functional membranes for antibacterial activity, and enantioselective separation. Knowledge gaps persist in scalable and environmentally friendly synthesis, broader coverage of underexplored application spaces, and the translation of host–guest design rules into predictive structure–property relationships. Continued progress positions CD-COFs as a versatile platform for next-generation functional materials that address challenges in separation science, energy storage, and environmental remediation.