Leveraging Ligand Desymmetrization to Enrich Structural Diversity of Zirconium Metal–Organic Frameworks for Toxic Chemical Adsorption

Abstract

The discovery of metal–organic frameworks (MOFs) with novel structures provides significant opportunities for developing porous solids with new properties and enriching the structural diversity of functional materials for various applications. The rational design of building units with specific geometric conformations is essential to direct the construction of MOFs with unique properties. Herein, we leverage a ligand desymmetrization approach to construct a series of new MOFs. A flexible tetratopic carboxylate ligand with a tetrahedral geometry was designed and assembled with a Zr6 cluster, generating four Zr‐based MOF structures: NU‐2600, NU‐2700, NU‐2800, and NU‐1802, in which the ligand configurations and Zr6 cluster connectivities can be controlled by varying solvents and modulators during synthesis. Except for NU‐1802, these represent entirely new topologies. Notably, NU‐1802 exhibits structural flexibility, with up to a 74% reduction in the unit cell volume as confirmed by single‐crystal X‐ray diffraction studies. Given their microporous structures, we studied the adsorption behaviors of n‐hexane and 2‐chloroethyl ethyl sulfide to explore the structure‐property relationships of these MOFs. Overall, this work highlights ligand desymmetrization as a powerful method to enrich MOF structural diversity and access complex MOFs with non‐default topologies suitable for applications such as toxic gas capture.