Benchmark Ab Initio Characterization of the Abstraction and Substitution Pathways of the Cl + CH3CN Reaction
We investigate the reaction pathways of the Cl + CH3CN system: hydrogen abstraction, methyl substitution, hydrogen substitution, and cyanide substitution, leading to HCl + CH2CN, ClCN/CNCl + CH3, ClCH2CN + H, and CH3Cl + CN, respectively. Hydrogen abstraction is exothermic and has a low barrier, whe...
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Dokumentumtípus: | Cikk |
Megjelent: |
2022
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Sorozat: | JOURNAL OF PHYSICAL CHEMISTRY A
126 No. 18 |
Tárgyszavak: | |
doi: | 10.1021/acs.jpca.2c01376 |
mtmt: | 32895238 |
Online Access: | http://publicatio.bibl.u-szeged.hu/24762 |
Tartalmi kivonat: | We investigate the reaction pathways of the Cl + CH3CN system: hydrogen abstraction, methyl substitution, hydrogen substitution, and cyanide substitution, leading to HCl + CH2CN, ClCN/CNCl + CH3, ClCH2CN + H, and CH3Cl + CN, respectively. Hydrogen abstraction is exothermic and has a low barrier, whereas the other channels are endothermic with high barriers. The latter two can proceed via a Walden inversion or front-side attack mechanism, and the front-side attack barriers are always higher. The C-side methyl substitution has a lower barrier and also a lower endothermicity than the N-side reaction. The computations utilize an accurate composite ab initio approach and the explicitly correlated CCSD(T)-F12b method. The benchmark classical and vibrationally adiabatic energies of the stationary points are determined with the most accurate CCSD(T)-F12b/aug-cc-pVQZ energies adding further contributions of the post-(T) and core correlation, scalar relativistic effects, spin-orbit coupling, and zero-point energy corrections. These contributions are found to be non-negligible to reach subchemical accuracy. © |
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Terjedelem/Fizikai jellemzők: | 2802-2810 |
ISSN: | 1089-5639 |