Separation of xylenes by enclathration

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Materials Science

Background:

• Xylene isomers (ortho-, meta-, para-) present separation challenges due to similar physical properties.
• Enclathration offers a potential method for selective molecular separation and host-guest complex formation.

Purpose of the Study:

• To investigate the efficacy of novel host compounds for separating xylene isomers using enclathration.
• To elucidate the structural characteristics of host-xylene isomer complexes.
• To evaluate the energetic stability of specific clathrate structures.

Main Methods:

• Enclathration experiments utilizing three distinct host molecules: 9,9'-bianthryl (H1), 9,9'-spirobifluorene (H2), and trans-2,3-dibenzoylspiro[cyclopropane-1,9-fluorene] (H3).
• Single-crystal X-ray diffraction to determine the structures of host-guest complexes.
• Lattice energy calculations for selected clathrates.

Main Results:

• Successful separation of xylene isomers was achieved through enclathration with the employed host compounds.
• The crystal structures of complexes formed between each host and a single xylene isomer were determined.
• Relative lattice energies were computed for the clathrates of 9,9'-bianthryl (H1) with ortho- and para-xylene.

Conclusions:

• The studied host compounds demonstrate potential for selective xylene isomer separation via enclathration.
• Structural insights provide a basis for understanding the host-guest interactions and selectivity mechanisms.
• Energetic evaluation aids in predicting and optimizing the stability of clathrate formation.