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Updated: Oct 20, 2025
06:24
High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
6.6K
Helical mesoscopic crystals based on an achiral charge-transfer complex with controllable untwisting/breaking
Canglei Yang1, Lixing Luo1, Jinqiu Chen1
1State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China. iamjingzhang@njupt.edu.cn.
Chemical Communications (Cambridge, England)
|September 10, 2021
Summary
Researchers created dynamic helical structures from achiral molecules. These structures respond to stimuli like solvents, enabling untwisting and deformation for applications in biomimetics and mechanical actuators.
Area of Science:
- Supramolecular chemistry
- Materials science
- Chemical engineering
Background:
- Synthetic helical structures from achiral molecules are crucial for biomimetics and mechanical actuators.
- Chirality modulation via external stimuli is key to designing helical supramolecular structures through symmetry breaking.
Purpose of the Study:
- To synthesize a metastable complex crystal with a torsional backbone from achiral components.
- To investigate the stimulus-responsive behavior and dynamic motion of the self-assembled helical microstructures.
Main Methods:
- Synthesis of a metastable complex Form 1 crystal using pyrene and DTTCNQ components via a quick cooling method.
- Utilizing C-H⋯N hydrogen bonds to form the torsional backbone.
- Observing helix motion kinetics influenced by crystal thickness and polar solvents.
Main Results:
- A metastable complex Form 1 crystal was successfully synthesized.
- Helical microstructures exhibited untwisting in liquid media, forming needle-like crystals.
- The structures demonstrated predictable deformation (untwisting or breaking) under stimulus-responsive strain-relaxing phase transformation.
Conclusions:
- A novel approach for forming helical morphologies from achiral binary supramolecules was demonstrated.
- The dynamic motion and stimulus-responsive transformations are vital for developing advanced biomimetics and mechanical actuators.
- This study provides insights into controlling helical structures for functional material applications.
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