We herein report the fabrication of a palladium nanoparticles (Pd NPs) loaded homochiral covalent organic framework using S-(+)-2-methylpiperazine and cyanuric chloride (Pd@CCOF-MPC) (2) via a very facile chemical approach. The chiral COF support of 1 (CCOF-MPC) is synthesized by the combination of cyanuric chloride and S-(+)-2-methylpiperazine at 90 °C for 36 h, and the Pd NPsloaded Pd@CCOF-MPC ( 2) is prepared via sequential solution impregnation and NaBH 4 reduction at room temperature. 2, as a highly active reusable asymmetric heterogeneous composite catalyst, is able to effectively promote the Henry reaction and reductive Heck reaction in high yield with excellent stereoselectivity.

A robust Zr-MOF (LIFM-28) containing replaceable coordination sites for additional spacer installation has been employed to demonstrate a swing- or multirole strategy for multifunctional MOFs. Through reversible installation/uninstallation of two types of spacers with different lengths and variable functional groups, different tasks can be accomplished using the same parent MOF. An orthogonal optimizing method is applied with seven shorter (L) and six longer (L) spacers to tune the functionalities, achieving multipurpose switches among gas separation, catalysis, click reaction, luminescence, and particularly, ultrahigh methane storage working capacity at 5-80 bar and 298 K.

To combine flexibility and modifiability towards a more controllable complexity of MOFs, a post-synthetic variable-spacer installation (PVSI) strategy is used to implement kinetic installation/ uninstallation of secondary ligands into/from a robust yet flexible proto-Zr-MOF. This PVSI process features precise positioning of spacers with different length, size, number, and functionality, enabling accurate fixation of successive breathing stages and fine-tuning of pore surface. It shows unprecedented synthetic tailorability to create complicated MOFs in a predictable way for property modification, for example, CO2 and R22 adsorption/separation, thermal/chemical stability, and extended breathing behavior.

We demonstrate herein a facile strategy to engineer versatile catalytically active coordination interspace in the same primitive metal–organic framework (MOF) for variable heterogeneous catalysis. Different functional ligands can be reversibly inserted into and removed from proto-LIFM-28 individually or successively to bring in single or binary catalytic sites for specific reactions and switch the parent MOF to multipurpose catalysts. Alcohol-oxidation, Knoevenagel-condensation, click, acetal, and Baylis–Hillman reactions are achievable through simple exchange of a single catalytic spacer, while sequential or stepwise reactions are designable via selective combination of two catalytic spacers with different functionalities, thus making proto-LIFM-28 a multivariate MOF for multiuse and economic catalysis.

Herein, a dynamic spacer installation (DSI) strategy has been implemented to construct a series of multifunctional metal—organic frameworks (MOFs), LIFM‐61/31/62/63, with optimized pore space and pore environment for ethane/ethylene separation. In this respect, a series of linear dicarboxylic acids were deliberately installed in the prototype MOF, LIFM‐28, leading to a dramatically increased pore volume (from 0.41 to 0.82 cm3 g−1) and reduced pore size (from 11.1×11.1 Å2 to 5.6×5.6 Å2). The increased pore volume endows the multifunctional MOFs with much higher ethane adsorption capacity, especially for LIFM‐63 (4.8 mmol g−1), representing nearly three times as much ethane as the prototypical counterpart (1.7 mmol g−1) at 273 K and 1 bar. Meanwhile, the reduced pore size imparts enhanced ethane/ethylene selectivity of the multifunctional MOFs. Theoretical calculations and dynamic breakthrough experiments confirm that the DSI is a promising approach for the rational design of multifunctional MOFs for this challenging task.

In multiphoton excited fluorescence (MPEF), highenergy upconversion emission is obtained from low-energy excitation by absorbance of two or more photons simultaneously.I napressure-induced fluorochromic process,t he emission energy is switched by outer pressure stimuli. Now,five metal-organic frameworks containing the same ligand with simultaneous multiphoton absorption and pressure-induced fluorochromic attributes were studied. One-, two-, and threephoton excited fluorescence (1/2/3PEF) can be achieved in the frameworks,w hich exhibit pressure-induced blue-to-yellow fluorochromism. The performances are closely dependent with the topologies,f lexibilities,a nd packing states of the frameworks and chromophores therein. The multiphoton upconversion performance can be intensified by pressure-related structural contraction. Over ten-fold increment in the 2PA active cross-section up to 2217 GM is achieved in pressed LIFM-114 compared with the 210 GM for pristine sample at 780 nm.

We transformed the hydrophilic metal–organic framework (MOF) UiO‐67 into hydrophobic UiO‐67‐Rs (R=alkyl) by introducing alkyl chains into organic linkers, which not only protected hydrophilic Zr6O8 clusters to make the MOF interspace superoleophilic, but also led to a rough crystal surface beneficial for superhydrophobicity. The UiO‐67‐Rs displayed high acid, base, and water stability, and long alkyl chains offered better hydrophobicity. Good hydrophobicity/oleophilicity were also possible with mixed‐ligand MOFs containing metal‐binding ligands. Thus, a (super)hydrophobic MOF catalyst loaded with Pd centers efficiently catalyzed Sonogashira reactions in water at ambient temperature. Studies of the hydrophobic effects of the coordination interspace and the outer surface suggest a simple de novo strategy for the synthesis of superhydrophobic MOFs that combine surface roughness and low surface energy. Such MOFs have potential for environmentally friendly catalysis and water purification.

Condensation of benzene-1,3,5-tricarbohydrazide with benzene-1,4-dicarboxaldehyde generated a new covalent organic framework, COF-ASB (1), in which the organic units are held together via hydrazone linkage to form porous frameworks. COF-ASB (1) is highly crystalline and displays good chemical and thermal stability and is permanently porous. In addition, 1 can be an ideal support to load Ru nanoparticles (Ru NPs) to generate Ru@COF-ASB (2). The obtained composite material is able to highly promote one-pot tandem synthesis of imine products from benzyl alcohols and corresponding amines under solvent-free conditions in air.