Unraveling the Surface Chemistry of Aluminum Oxo Archimedean Cages for Efficient Serial Adsorption

Multifunctional materials that meet diverse application needs hold profound significance in resource optimization, efficiency enhancement, and environmental sustainability. However, the development of these materials faces numerous challenges, including raw material acquisition, design feasibility, and long-term stability. This study demonstrates the innovative application of the surface chemistry of aluminum oxo Archimedean cages in efficient serial adsorption. The "Four-in-One" surface chemistry enables various single-crystal-to-single-crystal (SC-SC) structural transformations, involving ligand modification, cation exchange, post-synthetic metalation, and metal elimination, successfully achieving the first reversible SC-SC transformation from cluster structures to infinite frameworks. The fundamental reason behind these dynamic structural changes lies in the exceptional balance between rigidity and flexibility provided by the intercluster tri-pyrazole sites on the Archimedean cages. This diverse structural transformation characteristic offers extensive application potential for solid-liquid and solid-gas serial adsorption. For instance, this material effectively adsorbs heavy metal ions in water treatment and can subsequently be used for the permanent fixation of gaseous radionuclides. This work not only deepens our understanding of dynamic chemistry but also provides guiding significance for environmental remediation.