Hydrogen‐Bonded Metal–Nucleobase Frameworks for Efficient Separation of Xenon and Krypton

Abstract Xe/Kr separation is an industrially important but challenging process owing to their inert properties and low concentrations in the air. Energy‐effective adsorption‐based separation is a promising technology. Herein, two isostructural hydrogen‐bonded metal–nucleobase frameworks (HOF‐ZJU‐201 and HOF‐ZJU‐202) are capable of separating Xe/Kr under ambient conditions and strike an excellent balance between capacity and selectivity. The Xe capacity of HOF‐ZJU‐201a reaches 3.01 mmol g −1 at 298 K and 1.0 bar, while IAST selectivity and Henry's selectivity are 21.0 and 21.6, respectively. Direct breakthrough experiments confirmed the excellent separation performance, affording a Xe capacity of 25.8 mmol kg −1 from a Xe/Kr mixed‐gas at dilute concentrations. Density functional theory calculations revealed that the selective binding arises from the enhanced polarization in the confined electric field produced by the electron‐rich anions and the electron‐deficient purine heterocyclic rings.