Structural Engineering of a Zn 4 O-Based Metal–Organic Framework via Geometric Deformation of Secondary Building Units for Enhanced Trace Benzene Adsorption

Conformation engineering of building units has shown great potential in metal–organic frameworks (MOFs), enabling the construction of novel architectures with distinct topologies and thereby enriching the structural diversity of MOFs. However, research associated with the geometrically deformable metal-containing units without altering connectivity remains scarce. Here, we report the synthesis of a new Zn 4 O-based MOF, namely, WUST-4, with a 1,3,5-tris(4-carboxyphenyl)benzene (H 3 BTB) linker. Although sharing similar building units like the isomer MOF-177, WUST-4 features an unprecedented topological net due to the different geometries of Zn 4 O clusters and conformations of BTB linkers under controlled solvent conditions. Particularly, the Zn 4 O cluster in WUST-4 exhibits a unique distorted trigonal prismatic geometry, which is seldomly observed in other Zn 4 O-based MOFs. This geometric deformation arises from cooperative linker migration and solvent coordination, diverging from the conventional octahedral Zn 4 O configuration. Owing to unique pore structures with narrow traps and coordinatively unsaturated Zn 2+ sites along the channel walls, WUST-4 shows a higher benzene uptake at low pressure than MOF-177, suggesting its potential in the application of trace benzene removal.