Amplification of Asymmetry via Structural Transitions in Supramolecular Polymer-Surfactant Coassemblies

Area of Science:

• Supramolecular chemistry
• Materials science
• Chirality studies

Background:

• Asymmetric structures are crucial in nature and biointeractive materials.
• Controlling hierarchical asymmetry in synthetic, water-soluble systems remains a challenge.
• Homochirality is the uniform principle in natural systems.

Purpose of the Study:

• To investigate the amplification of helical asymmetry in benzene-1,3,5-tricarboxamide (BTA) supramolecular polymers.
• To explore the coassembly mechanism between BTA and chiral surfactants.
• To understand how molecular chirality influences macroscopic supramolecular structures.

Main Methods:

• Coassembly of BTA with homochiral nonionic surfactants.
• Spectroscopic techniques to analyze structural changes.
• Microscopy to observe fiber morphology and handedness.

Main Results:

• Strong amplification of molecular chirality from surfactants to BTA polymers was observed.
• Coassembly led to a shift from racemic double helices to single helices with preferred handedness.
• The coassembly mechanism was consistent across different chiral surfactants, indicated by maxima at identical stoichiometric ratios.
• Introduction of stereogenic centers in BTA overrode surfactant-induced asymmetry.

Conclusions:

• Supramolecular polymer-surfactant coassembly effectively amplifies helical asymmetry.
• This process offers a method to control the handedness of synthetic supramolecular polymers.
• The findings provide valuable insights into the formation and properties of chiral coassembled structures.