Consequences of conformational flexibility in hydrogen-bond-driven self-assembly processes.

Area of Science:

• Supramolecular chemistry
• Organic synthesis
• Chiral materials

Background:

• Chiral molecules can self-assemble into ordered structures.
• The influence of solvent on self-assembly and resulting chirality is crucial.
• C3-symmetrical molecules offer unique structural possibilities.

Purpose of the Study:

• To synthesize and characterize novel chiral, C3-symmetrical trisamides.
• To investigate the self-assembly behavior of these trisamides in different alkane solvents.
• To understand the role of solvent in inducing or maintaining supramolecular chirality.

Main Methods:

• Synthesis of C3-symmetrical trisamides.
• Self-assembly studies in linear and cyclic alkanes.
• Circular dichroism spectroscopy to detect chirality (Cotton effect).
• Molecular dynamics (MD) simulations to probe conformations and chiral bias.

Main Results:

• Successful synthesis of chiral, conformationally flexible C3-symmetrical trisamides.
• Observation of a strong Cotton effect in supramolecular polymers formed in linear alkanes.
• Absence of a significant Cotton effect in cyclic alkanes.
• MD simulations revealed 2:1 amide conformations in both solvent types, but a chiral bias only in linear alkanes.

Conclusions:

• Chiral trisamides can form supramolecular polymers with solvent-dependent chirality.
• Linear alkanes promote a chiral bias in the self-assembly of these trisamides.
• The conformational flexibility and C3-symmetry are key factors in the observed phenomena.