3D Hydrogen‐Bonded Organic Framework Assembled from 1D Coordination Polymers for Efficient Gas Dehydration

Two -(2D) and three-dimensional (3D) porous coordination polymers have been extensively explored for their porous nature and thus gas separation, but one-dimensional (1D) materials remain much less explored due to their reliance on weaker, non-covalent interactions to sustain the permanent porosity. Recent significant advances on the construction of porous hydrogen-bonded organic frameworks (HOFs) through synergistic weak interactions have provided us with the promise and motivated us to explore porous HOFs using 1D coordination polymers (CPs), and their multifunctional properties. In this work, we present such a HOF, [Cu(bpy)(H₂PO₄)∙H₂O]_n (ZNU-30), constructed from a linear CP via hydrogen bonds, C─H⋯π, and π-π interactions. Upon thermal activation at 373 K under vacuum, ZNU-30 undergoes a reversible single-crystal-to-single-crystal transformation, yielding ZNU-30a with 1D channels. Notably, ZNU-30a exhibits exceptional hydrophilicity, featuring considerable water uptake at low humidity, rapid adsorption-desorption kinetics, mild regeneration conditions, and outstanding cycling stability over 100 adsorption-desorption cycles. Single-component gas adsorption isotherms reveal unique molecular sieving behavior, with preferential adsorption of water (100 mg g^-1) over CO₂ and C₁─C₃ alkene/alkanes (CH₄, C₂H₄, C₂H₆, C₃H₆, and C₃H₈) at 298 K. Single-crystal structural analysis and DFT calculations indicate that the selective adsorption of H₂O is facilitated by multiple hydrogen-bonding interactions within the framework. Breakthrough experiments further confirm the material's ability to efficiently separate trace water vapor from CH₄ and other gases.