Symmetry-Breaking in Carbon Nanohoops Enables Room-Temperature Ternary Single-Molecule Switching
Kaili Chang1,2, Qing-Song Deng3, Kai Song1
1Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
Angewandte Chemie (International Ed. in English)
|October 29, 2025
Summary
Researchers achieved room-temperature ternary switching in single-molecule electronics using engineered carbon nanohoops. This breakthrough enables multi-state operation for high-density information processing, overcoming previous limitations.
Area of Science:
- Molecular electronics
- Materials science
- Nanotechnology
Background:
- Single-molecule electronics promise ultra-dense information processing.
- Room-temperature operation is typically limited to binary states due to thermal and electronic averaging.
Purpose of the Study:
- To demonstrate robust ternary switching at room temperature using engineered carbon nanohoops.
- To explore molecular symmetry control for multistate charge transport.
Main Methods:
- Synthesized and characterized symmetry-engineered carbon nanohoops with embedded pyrene units.
- Fabricated single-molecule junctions and performed mechanical elongation experiments.
- Conducted first-principles transport calculations.
Main Results:
- Demonstrated three well-resolved conductance plateaus at room temperature, each separated by approximately one order of magnitude.
- Observed unambiguous and reproducible ternary switching.
- Calculations confirmed that symmetry-breaking-induced orbital localization discretizes tunneling pathways.
Conclusions:
- Molecular symmetry control is a viable design principle for achieving room-temperature multistate charge transport.
- This approach enables high-density single-molecule logic architectures.
- Overcomes limitations of binary switching in single-molecule electronics.
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