CO₂-Induced Phase Transfer of Amino-Modified ZIF-90 between Immiscible Liquid Phases for Recyclable Efficient Synergistic Catalysis

Abstract

Phase-transfer processes between immiscible liquids play a prominent part in various applications, particularly for separation and recovery of catalysts. Zeolitic-imidazolate frameworks (ZIFs), as a specific subset of metal–organic frameworks, have been proven to be encouraging candidates for catalysts or cocatalysts because of their appealing characteristics, whereas recovery and reusability of ZIFs still remain a challenge because of their submicrometer-to-micrometer size. In this work, a kind of amino-modified ZIF-90 was designed and prepared, and by adjusting the hydrophobicity and hydrophilicity of surface species, these ZIFs could reversibly transfer between organic solvents and water by alternate bubbling of CO2 and N2. It was found that the mechanism of the phase transfer was aroused from the reversible formation of hydrophilic salts upon CO2 addition. By employing this novel property of the functionalized ZIF-90, an efficient and regulable CuI-catalyzed cycloaddition was fulfilled wherein the amino-modified ZIF-90 was applied to encapsulate, activate and reuse the catalyst, and regulate the reaction.

Multiquenching-Based Aggregation-Induced Electrochemiluminescence Sensing for Highly Sensitive Detection of the SARS-CoV-2 N Protein

“…TPE–ZIF-90 and the amination of TPE–ZIF-90 were synthesized according to the literature with slight modification. , 0.05 g of PVP, 0.048 g of ICA, and TPE (0.0005 g) were dissolved in 2.5 mL of a 20% methanol solution and heated to 70 °C until solutes were completely dissolved. When the solution cooled to 42 °C, the mixed solution was added with 300 μL of a 0.42 M ZnNO 3 ·6H 2 O solution.…”

CO2-switchable amidine-modified ZIF-90-stabilized Pickering emulsions for controllable Knoevenagel condensation reactions

“…Therefore, gas triggers, especially CO 2 , are a good choice for commercialization. However, until now, there have been very limited reports on CO 2 -switchable MOF-stabilized Pickering emulsions, 49–52 leading to them being underdeveloped for further applications. In this case, it would be highly significant to engineer novel CO 2 -responsive MOF emulsifiers for the creation of smart Pickering emulsions for their diversified demands.…”