A bifunctional robust and highly porous imidazolium-based ionic liquid decorated UiO-67 type MOF (UiO-67-IL, 1) was successfully constructed via solvothermal assembly of the imidazolium-based ligand and Zr(IV) ions. It exhibits a highly selective adsorption for CO over CH and N. Furthermore, 1 herein can be used as a highly active heterogeneous catalyst for CO cycloaddition with epoxides under atmospheric pressure with or without cocatalyst TBAB (n-BuNBr).

A Pd nano particle (NP)-loaded and nano metal-organic framework (NMOF)-based Pickering emulsifier is reported. The poly[2-(diethylamino)ethyl methacrylate)] (PDEAEMA) chains were grafted onto UiO-66-type NPs via a postsynthetic approach to generate PDEAEMA-g-UiO-66 NMOF (termed as MOF-3). The Pd NPs-loaded Pd@MOF-3 was synthesized via solution impregnation. Stable toluene-in-water Pickering emulsion was prepared with emulsifier Pd@MOF-3. Notably, the obtained Pd@MOF-3 is pH-responsive, and it is able to trigger the emulsification (at neutral condition) and demulsification (at acidic condition) of toluene droplets. Furthermore, it can be a highly active interfacial catalyst to effectively promote one-pot Knoevenagel condensation-hydrogenation cascade reaction at ambient conditions. The pH-responsive property allowed it to be in situ separated and recycled by demulsifying via simply tuning the pH value at the end of the reaction. This smart Pickering emulsion catalytic system is robust, and it can be recycled at least five times without loss of its catalytic activity.

Metal-organic frameworks (MOFs) are widely used as porous materials in the fields of adsorption and separation. However, their practical application is largely hindered by limitations to their processability. Herein, new UiO-66-Urea-based flexible membranes with MOF loadings of 50 (1), 60 (2), and 70 wt % (3) were designed and prepared by post-synthetic polymerization of UiO-66-NH2 nanoparticles and a polyurethane oligomer under mild conditions. The adsorption behavior of membrane 3 towards four hydrophilic dyes, namely, eosin Y (EY), rhodamine B (RB), malachite green (MG), and methylene blue (MB), in aqueous solution was studied in detail. It exhibits strong adsorption of EY and RB but weak adsorption of MG and MB in aqueous solution. Owing to the selective adsorption of these hydrophilic dyes, membrane 3 can remove EY and RB from aqueous solution and completely separate EY/MB, RB/MG, and RB/MB mixtures in aqueous solution. In addition, the membrane is uniformly textured, easily handled, and can be reused for dye adsorption and separation.

The crown ether-based covalent organic frameworks show excellent phase-transfer catalytic performance in various nucleophilic substitution reactions.

A UiO-66-MOF-based membrane UiO-66-TEM (1) was prepared by the assembly of methacrylamide-decorated UiO-66-NH-Met with a thiol side chain-attached polysiloxane (PSI-SH) via a photoinduced thiol-ene click reaction. The obtained membrane 1 can be a platform to support Au nanoparticles (Au NPs) to generate an Au-MOF-polymer composite membrane Au@UiO-66-TEM (2). 1 and 2 can be used to build highly efficient continuous flow-through membrane reactors for Knoevenagel condensation of 4-nitrobenzaldehyde with malononitrile and 4-nitrophenol (4-NP) reduction at ambient temperature, respectively.

Well-defined discrete metal-organic cages have been widely explored in the field of supramolecular catalysis. However, these metal-organic cages have been rarely explored as heterogeneous catalysts for one-pot reactions. Herein, we present the first successful confinement self-assembly of (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)containing metal-organic cages within amino-functionalized mesoporous carbon to realize a new family of bifunctional heterogeneous catalyst (Cage@FDU-ED) for one-pot reactions. The orthogonal features of the isolated catalytically active sites within the obtained bifunctional catalyst lead to enhanced catalytic activities, selectivity, and recyclability with the overall transformation yielding up to 96% conversion. These results demonstrate that continuous chemical transformation with high efficiency is possible through careful design of catalytic sites in both metal-organic cages and mesoporous matrix isolatedly. This study paves a new way toward metal-organic cages as a promising platform for heterogeneous sequential reactions.

It has been a challenging topic and perpetual task to design and synthesize covalent macrocycles with characteristic self-assembling behaviors and excellent host-guest properties in supramolecular chemistry. Herein, we present a family of macrocyclic diphenylamine[n]arenes (DPA[n]s, n = 3–7) consisting of methyldiphenylamine units through a facile one-pot synthesis strategy. Unlike many other reported macrocyclic arenes, the resultant non-planar DPA[n]s feature intrinsic π-π stacking interactions, interesting self-assembling behaviors and ethene/ethyne capture properties. Specifically, strong multiple intermolecular edge-to-face aromatic interactions in DPA[3] have been systematically investigated both in solid and solution states. The intriguing findings on the intermolecular edge-to-face stacking interaction mode in the macrocycle would further highlight the importance of noncovalent π-π interaction in supramolecular self-assembly. This study will also shed light on the macrocyclic and supramolecular chemistry and, we expect, will provide a direction for design and synthesis of covalent macrocycles in this area.

The topic of noncovalent spin−spin interactions is of increasing general interest in supramolecular radical chemistry. In this report, a series of exoand endo-TEMPO radical-functionalized metallacycles 1−4 and metallacages 5 and 6 were constructed via coordination-driven selfassembly, wherein the number, location, and distance of the spins were precisely controlled. Their intriguing spin−spin interactions were systematically investigated by electron paramagnetic resonance (EPR) and were well interpreted at the molecular level assisted by X-ray crystallography analysis. The results revealed their distinct spin−spin interactions in the solution state, wherein the spin−spin interaction of metallacycle 3 was much stronger than that of the other five assemblies mainly due to its shorter intramolecular spin−spin distance. In the solid state, 1−6 exhibited obvious spin−spin (dipole−dipole) interactions because of the close arrangement of TEMPO units as indicated in their single crystals. Specifically, a large zero-field splitting (ZFS; D = 17.5 mT) was observed in the crystalline form of metallacycle 4, which arose from the strong intermolecular spin−spin coupling. Interestingly, when the counterion of PF 6 − in 4 was changed to BF 4 − , the BF 4 − counterion analog 4a also exhibited a large ZFS, but the ZFS originated from the intramolecular spin−spin interaction due to a small variation in its crystal conformation. Moreover, the reversible on−off switching of the ZFS in 4 and 4a via the crystal-to-amorphous transformation induced by mechanical grinding and solvent vapor stimuli was also successfully realized. The unique and controllable inter-and intramolecular spin−spin interactions in this work reveal new insights for the understanding and manipulation of spin−spin interactions and may open up a new way to develop organic spin materials in the future.