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Emergent complexity of quantum rotation tunneling
Yilin Guo1, Chen Yang1, Xinmiao Xie1
1Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P. R. China.
Science Advances
|February 5, 2025
Summary
Researchers monitored single aromatic chain rotations in graphene electrodes. Quantum tunneling, not free rotation, dominates phenyl ring dynamics at low temperatures, revealing complex intramolecular movements.
Area of Science:
- Molecular Dynamics
- Quantum Mechanics
- Materials Science
Background:
- Conformational isomerism is crucial for material performance and biomolecular activity.
- Studying conformational isomerization dynamics at the single-molecule level remains challenging.
Purpose of the Study:
- To present real-time electrical monitoring of single aromatic chain rotation dynamics.
- To investigate the mechanisms governing phenyl ring rotations at low temperatures.
- To reveal complex intramolecular rotation behaviors in single molecules.
Main Methods:
- Real-time in situ electrical monitoring.
- Single-molecule level analysis.
- Covalent embedding of aromatic chains in graphene electrodes.
Main Results:
- Full rotation dynamics of a single aromatic chain were monitored with single-event resolution.
- Phenyl ring rotations at low temperatures are dominated by quantum rotation tunneling.
- Complex intramolecular rotations, including unidirectional rotations with varying delays driven by inelastic electron tunneling, were observed.
Conclusions:
- This study bridges macroscopic and microscopic understanding of molecular dynamics.
- It enhances insights into structure-activity relationships.
- The findings suggest potential for imparting new functions to ordinary materials through controlled molecular rotations.
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