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.

In contrast to the vast Al-oxo molecular cluster chemistry, Al-based building units for metalorganic framework (MOF) construction are limited in structural diversity and complexity. Synthesis of single crystalline MOFs based on this "hard" metal is further complicated by the poor reversibility of the Al-organic coordination linkages. Here, a strategy to employ two kinds of linkages with distinct strength-strong Alcarboxylate linkage and weak Cu-pyrazol N linkagegives FDM-91 (FDM = Fudan Materials) with gigantic Al 24 -based units. After replacing the weak moieties with organic linkers post-synthetically, two new stable MOFs with exceptional water harvesting capacity (up to 0.53 g g À 1 ) and outstanding cycling performance are developed. Linkage-selective dissociation of FDM-91 further leads to the isolation of the Al 24 molecular clusters. The versatile chemistry performed here to reinforce or deconstruct MOFs provides a new way to make important extended and discrete structures.

Terminal ligand exchange and framework linker exchange have been frequently practiced as powerful tools to functionalize reticular structures such as metal–organic frameworks (MOFs). Herein, we report the postsynthetic modification (PSM) of a 6-connected layered MOF (hxl topology) to achieve a 12-connected fcu framework. In the PSM process, isometric linker exchange in the layers and linker installation between adjacent layers by the substitution of modulating ligands happen simultaneously. Snapshots of PSM at different time points reveal that the hxl domain is adaptively reorganized to create sites for new linker installation, and gradually the fcu domain dominates the crystal. Detailed kinetic analysis suggests that, although adaptive linker installation requires interlayer expansion of stackings in situ, it is kinetically faster than isometric linker exchange in the layers.