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Updated: Feb 24, 2026

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Published on: August 18, 2017

Acoplamiento Radial en la Intersección Cónica Gobierna las Vías de Fragmentación Competitivas en Cationes de

Yupeng Liu¹, Cong-Cong Jia², Peipei Ge¹

¹Huazhong University of Science and Technology, Wuhan National Laboratory for Optoelectronics and School of Physics, Wuhan 430074, China.

Physical review letters

|February 22, 2026

Abstract:

Controlling selective bond cleavage in polyatomic molecules remains a fundamental challenge in photochemistry, primarily due to nonadiabatic dynamics at conical intersections. By combining time-resolved Coulomb explosion imaging with quantum wave packet simulations, we report a striking reversal in bond selectivity for two structurally similar halomethane cations under strong laser fields, i.e., CH_{3}Cl^{+} predominantly undergoes C-Cl cleavage, whereas CH_{3}F^{+} favors C-H fission. We attribute this contrast to the halogen-dependent strength of radial coupling at the conical intersection between the A and B electronic states. The strong coupling in CH_{3}Cl^{+} diverts the wave packet to the repulsive A state, enhancing C-Cl cleavage and opening an indirect resonant Raman excitation pathway for C-H rupture. In contrast, the weaker coupling in CH_{3}F^{+} restricts the dynamics primarily to direct Raman excitation, resulting in dominant C-H bond fission. Our findings establish radial coupling strength at conical intersections as a key control parameter for multibond fragmentation and suggest new avenues for laser-driven reaction control through targeted manipulation of nonadiabatic couplings.

Palabras clave:

escisión selectiva de enlaces cationes de halometano campos láser acoplamientos no adiabáticos intersecciones cónicas acoplamiento radial dinámica de paquetes de ondas imágenes de explosión de Coulomb simulaciones de paquetes de ondas cuánticas modelado teórico física química dinámica molecular

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