Hexagonal Lyotropic Liquid Crystal from Simple "Abiotic" Foldamers.

Area of Science:

• Synthetic chemistry
• Materials science
• Supramolecular chemistry

Background:

• Foldamer chemistry aims to create synthetic molecules that mimic natural biomolecules like peptides.
• While peptides self-assemble into complex structures, abiotic foldamers often struggle to form tertiary assemblies.
• A challenge exists in developing synthetic foldamers with peptide-like assembly capabilities.

Purpose of the Study:

• To design and synthesize a novel foldamer scaffold capable of forming ordered assemblies.
• To investigate the self-assembly behavior of these new foldamers in solution.
• To explore the potential of these foldamers in creating stable supramolecular structures.

Main Methods:

• Synthesis of a novel foldamer scaffold featuring p-phenyleneethynylene units linked by chiral carbon atoms.
• Solution behavior analysis of oligomers at varying concentrations using techniques like microscopy.
• Lyotropic liquid crystal (LC) phase formation and characterization in dichloromethane (CH2Cl2).

Main Results:

• Oligomers exhibited random coil behavior in very dilute solutions.
• Hexamers and octamers formed hexagonal lyotropic liquid crystalline phases above critical concentrations.
• Microscopy confirmed the assembly of foldamers into nanofibers within the LC phases.
• These nanofibers demonstrated remarkable stability, persisting after dilution of the LC phase.

Conclusions:

• The novel foldamer scaffold successfully self-assembled into ordered nanofiber structures.
• The observed stability of the assembled nanofibers is attributed to the foldamer's compact backbone and rigid side chains.
• This work presents a promising abiotic system for creating stable, peptide-like supramolecular architectures.