Theoretical Study of the Reactions of Methane and Ethane with Electronically Excited N2(A3Σu+)
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- 作者：Alexander S. Sharipov ; Boris I. Loukhovitski ; Alexander M. Starik
- 刊名：Journal of Physical Chemistry A
- 出版年：2016
- 出版时间：June 30, 2016
- 年：2016
- 卷：120
- 期：25
- 页码：4349-4359
- 全文大小：562K
- 年卷期：0
- ISSN：1520-5215
文摘
Comprehensive quantum chemical analysis with the usage of density functional theory and post-Hartree–Fock approaches were carried out to study the processes in the N2(A3Σu+) + CH4 and N2(A3Σu+) + C2H6 systems. The energetically favorable reaction pathways have been revealed on the basis of the examination of potential energy surfaces. It has been shown that the reactions N2(A3Σu+) + CH4 and N2(A3Σu+) + C2H6 occur with very small or even zero activation barriers and, primarily, lead to the formation of N2H + CH3 and N2H + C2H5 products, respectively. Further, the interaction of these species can give rise the ground state N2(X1Σg+) and CH4 (or C2H6) products, i.e., quenching of N2(A3Σu+) by CH4 and C2H6 molecules is the complex two-step process. The possibility of dissociative quenching in the course of the interaction of N2(A3Σu+) with CH4 and C2H6 molecules has been analyzed on the basis of RRKM theory. It has been revealed that, for the reaction of N2(A3Σu+) with CH4, the dissociative quenching channel could occur with rather high probability, whereas in the N2(A3Σu+) + C2H6 reacting system, an analogous process was little probable. Appropriate rate constants for revealed reaction channels have been estimated by using a canonical variational theory and capture approximation. The estimations showed that the rate constant of the N2(A3Σu+) + C2H6 reaction path is considerably greater than that for the N2(A3Σu+) + CH4 one.