Potassium-thiacalix[8]arene assembly: structure and guest sorption profiles

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Crystal Engineering

Background:

• Thiacalixarenes are macrocyclic compounds with tunable host-guest properties.
• Zeolitic structures offer porous frameworks for molecular adsorption.
• Potassium adducts can stabilize unique coordination environments.

Purpose of the Study:

• To synthesize and characterize a novel potassium adduct of thiacalix[8]arene.
• To investigate the structural properties and adsorption capabilities of the resulting material.
• To explore the reversible binding of guest molecules within the porous framework.

Main Methods:

• Reaction of thiacalix[8]arene with potassium hydride (KH) in tetrahydrofuran (THF).
• Recrystallization from methanol to obtain the crystalline adduct [K4(3.4H)].8MeOH.
• Characterization of the crystal structure and adsorption properties.

Main Results:

• A pale yellow crystalline adduct [K4(3.4H)].8MeOH was successfully synthesized.
• The adduct exhibits a highly extensive coordination network, forming a zeolitic structure.
• The derived apohost [K4(3.4H)] demonstrated reversible adsorption of gaseous organic molecules, including methanol and benzene.
• Adsorption of methanol resulted in the regeneration of the original adduct structure.

Conclusions:

• The potassium adduct of thiacalix[8]arene forms a stable, porous zeolitic framework.
• This framework acts as an effective host for reversible adsorption of organic guest molecules.
• The host-guest system demonstrates potential for applications in molecular separation and storage.