Porous liquids with chemical separation properties are quite well-studied in general, but there is only a handful of reports in the context of identification and separation of non-gaseous molecules. Herein, we report a Type II porous ionic liquid composed of coordination cages that exhibits exceptional selectivity towards l-tryptophan (l-Trp) over other aromatic amino acids. A previously known class of anionic organic–inorganic hybrid doughnut-like cage (HD) is dissolved in trihexyltetradecylphosphonium chloride (THTP_Cl). The resulting liquid, HD/THTP_Cl, is thereby composed of common components, facile to prepare, and exhibit room temperature fluidity. The permanent porosity is manifested by the high-pressure isotherm for CH₄ and modeling studies. With evidence from time-dependent amino acid uptake, competitive extraction studies and molecular dynamic simulations, HD/THTP_Cl exhibit better selectivity towards l-Trp than other solid state sorbents, and we attribute it to not only the intrinsic porosity of HD but also the host-guest interactions between HD and l-Trp. Specifically, each HD unit is filled with nearly 5 l-Trp molecules, which is higher than the l-Trp occupation in the structure unit of other benchmark metal-organic frameworks.

The fine-tuning of MBBs in Zn-MOF-74 through post-synthetic cation exchange with Ca²⁺ significantly enhances its basicity. The resulting Ca/Zn-MOF-74 gives an improved product yield over Zn-MOF-74 and Ni/Zn-MOF-74 in Knoevenagel condensation.

Solid base catalysts featuring green, robustness, and high activity play an important role in the current fine-chemical and petrochemical industry. Normally, the generation of supported K₂O by thermal decomposition of KNO₃ requires high temperature, and this process can sometimes destroy the structure of supporting materials. We herein report a solvent-assisted stepwise redox (SASR) approach to generate zeolite NaA-supported K₂O, which we call K₂O/NaA, that function as the solid base catalyst for Michael addition reaction between ethanol and ethyl acrylate. The solvent-assisted redox decomposition process of KNO₃ at elevated temperature was investigated by thermogravimetry–mass spectrometry. It reveals that after reducing a minor amount of KNO₃ at 400 °C, the organic solvent decomposes to form carbon, which promotes the reduction of KNO₃ to generate strong basicity on the zeolite NaA at 600 °C. The resulting material, K₂O/NaA-S, exhibits improved catalytic activity in Michael addition reaction over other benchmark base catalysts that have been used in this reaction. This catalyst is durable for at least four catalytic cycles without apparent loss in activity. K₂O/NaA-S exhibits larger reaction rate constant yet lower activation energy than K₂O/NaA prepared by thermal decomposition method. The SASR approach described in this paper represents a new blueprint for the generation of the supported alkali oxide as the solid base catalyst.