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Updated: Sep 17, 2025
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A Micropatterning Assay for Measuring Cell Chirality
Published on: March 11, 2022
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Chirality Unbound in Graphene Nanoribbons
Si Tong Bao1, Yongseok Hong1, Haoyu Jiang1
1Department of Chemistry, Columbia University, New York, New York, 10027, USA.
Angewandte Chemie (International Ed. in English)
|June 27, 2025
Summary
Researchers synthesized ultralong, chiral graphene nanoribbons (GNRs) with controlled helical twisting. These GNRs show record-breaking circular dichroism and function as room-temperature spin filters, paving the way for new chiroptical materials.
Area of Science:
- Materials Science
- Organic Chemistry
- Nanotechnology
Background:
- Graphene nanoribbons (GNRs) are promising materials with tunable electronic properties.
- Achieving controlled chirality and extended helical structures in GNRs remains a significant challenge.
Purpose of the Study:
- To demonstrate controlled helicity in extended graphene nanoribbons.
- To develop a high-yielding synthetic method for chiral GNRs.
- To investigate the chiroptical properties and spin-filtering capabilities of these novel GNRs.
Main Methods:
- Synthesis of defect-free, ultralong, chiral cove-edged GNRs using a robust method.
- Tuning helical twisting of the GNR backbone via functionalization with chiral side chains.
- Characterization of structural, chiroptical, and spin-selective properties.
Main Results:
- Demonstrated controlled, tunable helical twisting in extended GNRs.
- Synthesized GNRs up to 65 nm in length with nearly 10 helical rotations.
- Achieved an unprecedented circular dichroic response (|Δε| = 6780 M⁻¹ cm⁻¹ at 550 nm).
- Observed room-temperature spin filtering in thin films due to chirality-induced spin selectivity.
Conclusions:
- Established a new synthetic route for creating extended chiral GNRs with controlled helicity.
- Developed a novel chiroptical material with the highest recorded circular dichroic response for organic molecules.
- Showcased the potential of these GNRs as efficient room-temperature spin filters.
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