Precise Identification of Radioactive Iodine within Interlayer Molecular Cages of Metal–Organic Frameworks

Obtaining direct structural evidence to elucidate the intricate interactions between iodine and adsorbents remains a significant challenge in the development of more effective iodine capture platforms. To address this issue, we report a 2D Co-tib MOF with adaptive interlayer cages that enable precise iodine binding via synergistic I···π, I···H-phenyl, and I···N halogen bonds, as directly observed by single-crystal XRD. Importantly, the 1D pores formed by the Co-tib layered structure enhance the diffusion of I₂, facilitating its adaptive binding. Co-tib achieves record iodine capacities (7.68 g g^-1 in vapor, 2.3 g g^-1 in solution) while offering molecular-level mechanistic insights. In summary, this study provides critical insights and guidance for the design of materials with enhanced I₂ adsorption properties.