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Catalyst-Free Radical Reaction Driven by Interfacial Electric Fields in Organic Microdroplets under Ambient
Jin Luo1, Xulin Gong2, Haobin Ye1
1State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, China.
Journal of the American Chemical Society
|December 29, 2025
Summary
Intrinsic electric fields in organic microdroplets drive radical reactions without catalysts. This study demonstrates catalyst-free methylation using pyridine-dimethyl sulfoxide (DMSO) microdroplets, opening new avenues for organic synthesis.
Area of Science:
- Organic Chemistry
- Physical Chemistry
- Chemical Physics
Background:
- Static electric fields can drive chemical reactions.
- Interfacial electric fields are present at organic microdroplet interfaces.
Purpose of the Study:
- To demonstrate that intrinsic interfacial electric fields in organic microdroplets can drive radical reactions without external catalysts or applied potentials.
- To investigate the mechanism of catalyst-free methylation of pyridine using pyridine-dimethyl sulfoxide (DMSO) microdroplets.
Main Methods:
- Induced charge accumulation measurements
- Raman spectroscopy
- Isotopic labeling
- Spin-trapping experiments
- Density Functional Theory (DFT) calculations
Main Results:
- Strong interfacial electric fields were confirmed in pyridine-DMSO microdroplets.
- Catalyst-free methylation of pyridine to 2-methylpyridine was achieved at 21.1 μM/h under ambient conditions.
- A reaction mechanism involving electric-field-induced hydrogen and methyl radical generation was elucidated.
Conclusions:
- Intrinsic interfacial electric fields in organic microdroplets can effectively drive radical reactions.
- This strategy offers a novel approach for catalyst-free organic synthesis.
- The findings have broad potential for various radical-mediated organic reactions.
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