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Quantum Tunneling in Reactions Modulated by External Electric Fields: Reactivity and Selectivity
Zhifeng Ma1, Zeyin Yan1, Xin Li1
1Shenzhen Grubbs Institute, Department of Chemistry, and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, P. R. China.
The Journal of Physical Chemistry Letters
|January 27, 2023
Summary
External electric fields (EEFs) significantly impact reactions involving quantum tunneling by lowering energy barriers. This study reveals EEFs can control reaction rates and selectivity, even switching reactions on/off under cryogenic conditions.
Area of Science:
- Quantum chemistry
- Chemical kinetics
- Theoretical chemistry
Background:
- Quantum tunneling and external electric fields (EEFs) are known to influence chemical reactions.
- The combined effect of EEFs on tunneling-involved reactions and their temperature dependence requires further investigation.
Purpose of the Study:
- To investigate the synergetic effect of EEFs on reactions involving hydrogen- or carbon-tunneling.
- To understand the temperature-dependence of EEF effects on these reactions.
- To explore EEF modulation of tunneling-driven reactions and selectivity.
Main Methods:
- Density Functional Theory (DFT)
- Dual-level spin-scaled Complete Active Space Self-Consistent Field (DLPNO-CCSD(T1))
- Variational Transition-State Theory (VTST)
Main Results:
- Oriented EEFs reduce reaction barriers and widths via electrostatic stabilization, enhancing reaction rates.
- EEFs decrease crossover temperatures and quantum tunneling contributions.
- EEFs can modulate and switch tunneling-driven reactions, like hydroxycarbene 1,2-H migration, under cryogenic conditions.
- EEF/tunneling synergy can control chemo- or site-selectivity in molecules with multiple reactive sites.
Conclusions:
- EEFs play a crucial role in modulating quantum tunneling effects in chemical reactions.
- EEFs offer a powerful tool for controlling reaction rates, temperature dependence, and selectivity.
- This research opens new avenues for designing reactions with precise control under various conditions, including cryogenic environments.
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