Metal−organic frameworks (MOFs) with open metal sites (OMSs) have been shown to preferentially adsorb unsaturated hydrocarbons such as C 2 H 4 due to the formation of π-complexation. However, the adsorption capacity and selectivity might well be dampened under humid conditions because OMSs could be easily poisoned in the presence of water vapor. C 2 H 6selective adsorbents with less hydrophilic environments, on the other hand, not only could effectively minimize the impact of humidity on separation capacity but also could directly produce high-purity C 2 H 4 from C 2 H 6 /C 2 H 4 mixtures. Here, we report a C 2 H 6 -selective MOF (JNU-2) underlying a rare xae topology. Its cage-like cavities are interconnected through apertures with a limiting diameter of ca. 3.7 Å, which is in the domain of kinetic diameters of C 2 H 4 and C 2 H 6 molecules. Molecular modeling studies suggest the four oxygen atoms on aperture are poised to preferentially interact with C 2 H 6 through multiple C−H•••O hydrogen bonding, rendering JNU-2 an enhanced C 2 H 6 selectivity. Indeed, experimental results reveal that JNU-2 not only takes up a great amount of C 2 H 6 comparable to other top-performing C 2 H 6 -selective MOFs but also displays excellent separation capacity even under humid conditions; moreover, it can be easily regenerated at room temperature owing to its moderate adsorption enthalpy. This work successfully demonstrated a strategy of balancing adsorption capacity and selectivity for C 2 H 6 by designing MOF materials with cavities interconnected through tailored apertures. The apertures function as screening sites for C 2 H 6 selectivity, while the internal cavities provide space for large adsorption.

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Porous materials that can undergo pore‐structure adjustment to better accommodate specific molecules are ideal for separation and purification. Here, we report a stable microporous metal‐organic framework, JNU‐1, featuring one‐dimensional diamond‐shaped channels with a high density of open metal sites arranged on the surface for the cooperative binding of acetylene. Together with its framework flexibility and appropriate pore geometry, JNU‐1 exhibits an induced‐fit behavior for acetylene. The specific binding sites and continuous framework adaptation upon increased acetylene pressure are validated by molecular modeling and in situ X‐ray diffraction study. This unique induced‐fit behavior endows JNU‐1 with an unprecedented increase in the acetylene binding affinity (adsorption enthalpy: up to 47.6 kJ mol−1 at ca. 2.0 mmol g−1 loading).

Charge separation plays a crucial role in regulating photochemical properties and therefore warrants consideration in designing photocatalysts. Metal–organic frameworks (MOFs) are emerging as promising candidates for heterogeneous photocatalysis due to their structural designability and tunability of photon absorption. Herein, we report the design of a pyrazole–benzothiadiazole–pyrazole organic molecule bearing a donor–acceptor–donor conjugated π-system for fast charge separation. Further attempts to integrate such a photosensitizer into MOFs afford a more effective heterogeneous photocatalyst (JNU-204). Under visible-light irradiation, three aerobic oxidation reactions involving different oxygenation pathways were achieved on JNU-204. Recycling experiments were conducted to demonstrate the stability and reusability of JNU-204 as a robust heterogeneous photocatalyst. Furthermore, we illustrate its applications in the facile synthesis of pyrrolo­[2,1-a]­isoquinoline-containing heterocycles, core skeletons of a family of marine natural products. JNU-204 is an exemplary MOF platform with good photon absorption, suitable band gap, fast charge separation, and extraordinary chemical stability for proceeding with aerobic oxidation reactions under visible-light irradiation.

N,N-Dimethylformamide (DMF) is frequently used as a solvent because of its unique physical properties that allow it to solubilize both organic and inorganic substances. It has also found broad applications as a catalyst for a variety of chemical transformations and as a donor for many functional groups in synthetic organic chemistry. However, DMF is incompatible with a wide variety of substances and has resulted in many incidents over the years. Analysis of literature information indicates that those incompatible substances can be categorized as acids, bases, halogenated reagents, oxidants, and reductants. This comprehensive review of the potential hazards of using DMF in chemical reactions will serve as an educational resource to promote awareness of such safety hazards in the broader chemistry community and encourage scientists to develop appropriate control strategies to mitigate the potential safety risks associated with the use of DMF in chemical reactions.