Vibrational mode-specificity in the dynamics of the Cl + C2H6 â HCl + C2H5 reaction.
J Chem Phys
; 155(11): 114303, 2021 Sep 21.
Article
em En
| MEDLINE
| ID: mdl-34551541
ABSTRACT
We report a detailed dynamics study on the mode-specificity of the Cl + C2H6 â HCl + C2H5 H-abstraction reaction. We perform quasi-classical trajectory simulations using a recently developed high-level ab initio full-dimensional potential energy surface by exciting five different vibrational modes of ethane at four collision energies. We find that all the studied vibrational excitations, except that of the CC-stretching mode, clearly promote the title reaction, and the vibrational enhancements are consistent with the predictions of the Sudden Vector Projection (SVP) model, with the largest effect caused by the CH-stretching excitations. Intramolecular vibrational redistribution is also monitored for the differently excited ethane molecule. Our results indicate that the mechanism of the reaction changes with increasing collision energy, with no mode-specificity at high energies. The initial translational energy mostly converts into product recoil, while a significant part of the excess vibrational energy remains in the ethyl radical. An interesting competition between translational and vibrational energies is observed for the HCl vibrational distribution the effect of exciting the low-frequency ethane modes, having small SVP values, is suppressed by translational excitation, whereas a part of the excess vibrational energy pumped into the CH-stretching modes (larger SVP values) efficiently flows into the HCl vibration.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Chem Phys
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Hungria