In Situ Encapsulation of Cationic [2]Catenane in a Stable Zirconium Metal-Organic Framework

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Catalysis

Background:

• Metal-organic frameworks (MOFs) are versatile porous materials for hosting guest molecules.
• In situ encapsulation is a key method for incorporating diverse guests into MOFs.
• Encapsulation of cationic guests, particularly catenanes, in MOFs remains underexplored.

Purpose of the Study:

• To achieve in situ encapsulation of cationic catenanes within MOFs under mild conditions.
• To investigate the interactions between the MOF framework and cationic guests.
• To demonstrate a practical application of the resulting host-guest MOF composite.

Main Methods:

• In situ encapsulation of a cationic catenane (DA[2]C) in UiO-66-F4 MOF using water as a solvent at room temperature.
• Theoretical calculations to elucidate guest-framework interactions.
• Heterogeneous catalytic testing for the detoxification of 2-chloroethyl ethyl sulfide.

Main Results:

• Successful room-temperature in situ encapsulation of DA[2]C in UiO-66-F4 MOF.
• Strong interactions between the MOF's tetrafluoroterephthalic acid ligands and DA[2]C cations, driven by electrostatic forces and fluorine atom attraction.
• The DA[2]C·4Cl/UiO-66-F4 composite achieved >99% conversion and >97% selectivity in detoxifying 2-chloroethyl ethyl sulfide.

Conclusions:

• Developed a universal method for in situ encapsulation of cationic organic molecules in MOFs.
• Demonstrated the potential of MOF-based host-guest systems for catalytic applications.
• The approach is extendable to various cationic molecules, paving the way for new MOF applications.