A Multinary Metal–Organic Framework with Divided Linkers for C₂H₂/CO₂ Separation

Developing porous solid adsorbents with strong interactions toward C2H2 is crucial to achieve C2H2/CO2 separation with high selectivity. Herein, we introduce the concept of “divided linkers” for the construction of metal–organic frameworks (MOFs) with tailored pores and well-positioned adsorption sites. A single CuI node divides the pyrazyl-carboxylate linker 4,4′-(2,6-pyrazinediyl)dibenzoic acid into two equivalent edges. Furthermore, these edges reticulate with the pseudo-octahedral Zn-based building units to afford a porous multinary framework with single crystallinity and impressive chemical stability. Its appropriate pore size (6.4 Å) and high density of interacting sites empower the MOF with high capacity in C2H2 adsorption (104 cm3 g–1) and preferential C2H2 capture over CO2 (selectivity = 3.3) at 298 K. Potential use of the robust architecture for C2H2/CO2 separation is confirmed by the dynamic gas mixture breakthrough experiment.