Porous materials that can undergo pore-structure adjustment to better accommodate specific molecules are ideal for separation and purification. Here, we report a stable microporous metal-organic framework, JNU-1, featuring one-dimensional diamond-shaped channels with a high density of open metal sites arranged on the surface for the cooperative binding of acetylene. Together with its framework flexibility and appropriate pore geometry, JNU-1 exhibits an induced-fit behavior for acetylene. The specific binding sites and continuous framework adaptation upon increased acetylene pressure are validated by molecular modeling and in situ X-ray diffraction study. This unique induced-fit behavior endows JNU-1 with an unprecedented increase in the acetylene binding affinity (adsorption enthalpy: up to 47.6 kJ mol-1 at ca. 2.0 mmol g-1 loading).
Keywords: binding affinity; cooperative action; gas separation; induced fit; porous materials.
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