Chiral Membrane Containing Subnanometer Channels for Enantioselective Transport Amino Acids.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Separation Science

Background:

• Chiral separation is crucial for understanding life's origins and utilizing chiral molecules.
• Pillar[n]arenes are versatile macrocyclic hosts with tunable properties.
• Membrane-based separations offer efficient and scalable solutions for chiral resolution.

Purpose of the Study:

• To design and synthesize novel anionic and cationic chiral pillar[6]arenes.
• To construct a chiral pillar[6]arene membrane using layer-by-layer assembly.
• To investigate the chiral separation performance and mechanism of the fabricated membrane.

Main Methods:

• Synthesis of anionic and cationic pillar[6]arenes.
• Layer-by-layer assembly for membrane fabrication via electrostatic interactions.
• Chiral separation experiments using alanine enantiomers (L-Ala and D-Ala).
• Host-guest interaction studies and theoretical simulations.

Main Results:

• The chiral pillar[6]arene membrane exhibited selective transport of L-Ala over D-Ala (7.7-fold difference).
• A single separation step achieved an enantiomeric excess (ee) value of 62% for L-Ala.
• The study explored the influence of assembly method, layer number, and driving force on separation efficiency.

Conclusions:

• The developed chiral pillar[6]arene membrane possesses effective chiral separation capabilities.
• The findings provide a new platform for applying chiral pillar[n]arenes in membrane-based chiral separations.
• Understanding host-guest interactions is key to optimizing chiral recognition and transport.