Chiral crystal-like droplets displaying unidirectional rotational sliding

Area of Science:

• Supramolecular chemistry
• Soft matter physics
• Materials science

Background:

• Achieving structural ordering beyond the nanoscale in self-assembled organic materials is a significant challenge.
• Understanding the interplay between molecular chirality and macroscopic material behavior is crucial for designing advanced functional materials.

Purpose of the Study:

• To report the spontaneous self-assembly of a chiral discotic triphenylene derivative into millimetre-sized droplets.
• To investigate the structural integrity, fluid nature, and chiral-dependent dynamics of these supramolecular assemblies.

Main Methods:

• Spontaneous self-assembly of chiral discotic triphenylene derivatives.
• X-ray imaging to analyze internal structure during sliding.
• Rheological measurements to probe mechanical properties and enantiomeric differences.

Main Results:

• Formation of millimetre-sized droplets with high positional and orientational ordering, mimicking single crystals.
• Demonstration of fluid-like sliding behavior on a vertical substrate while maintaining internal structure.
• Observation of unidirectional droplet rotation (clockwise or counterclockwise) dependent on molecular chirality ((R)- vs. (S)-enantiomers).

Conclusions:

• Molecular chirality is a key factor controlling the macroscopic movement direction of supramolecular structures.
• These chiral droplets exhibit unique fluid and rotational dynamics, distinct from traditional soft materials.
• Findings expand the fundamental understanding of structure-dynamics relationships in chiral soft matter.