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Reversible Interconversion between a Carbon-Carbon Double Bond and Diradical beyond External Stimulus
Junyu Huang1, Liancheng He1,2, Runbo Pei1,2
1State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Journal of the American Chemical Society
|December 24, 2025
Summary
Researchers developed a new method using Lewis acids to twist carbon-carbon double bonds into stable diradical species. This reversible process opens doors for novel molecular design and responsive materials.
Area of Science:
- Organic Chemistry
- Materials Science
Background:
- Reversible interconversion between carbon-carbon double bonds and diradical species is a key challenge.
- Achieving stable diradical states via controlled bond twisting is difficult.
Purpose of the Study:
- To develop a strategy for controlled twisting of C═C bonds into diradical species.
- To explore the reversibility of this transformation.
Main Methods:
- Lewis acid coordination (Al(ORF)3 or SiEt3+) to bianthrone derivatives.
- Characterization using X-ray crystallography, EPR spectroscopy, and magnetic studies.
- Monitoring reversibility with UV-vis and NMR spectroscopy.
Main Results:
- Achieved controlled twisting of C═C bonds to over 70° using Lewis acids.
- Isolated and characterized stable twisted diradical adducts.
- Demonstrated reversible conversion back to folded alkenes upon Lewis acid displacement.
Conclusions:
- Lewis acid coordination provides a method to manipulate C═C bond topology and form diradicals.
- The diradical formation is reversible, enabling responsive molecular systems.
- Potential applications in molecular design and electronic materials.
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