An ab initio study of the Cl(P)+C2H6→C2H5+HCl abstraction reaction |
| |
Authors: | Orlando Roberto-Neto Francisco B C Machado |
| |
Institution: | a Instituto de Estudos Avançados, Centro Técnico Aeroespacial, São José dos Campos 12228-840, São Paulo, Brazil b Departamento de Química, Instituto Tecnológico de Aeronáutica, Centro Técnico Aeroespacial, São José dos Campos, 12228-900, São Paulo, Brazil |
| |
Abstract: | Electronic energies, geometries, and harmonic vibration frequencies for the reactants, products, and transition state for the Cl(3P)+C2H6→C2H5+HCl abstraction reaction were evaluated at the HF and MP2 levels using several correlation consistent polarized-valence basis sets. Single-point calculations at PMP2, MP4, QCISD(T), and CCSD(T) levels were also carried out. The values of the forward activation energies obtained at the MP4/cc-pVTZ, QCISD(T)/cc-pVTZ, and CCSD(T)/cc-pVTZ levels using the MP2/cc-pVTZ structures are equal to −0.1, −0.4, and −0.3 kcal/mol, respectively. The experimental value is equal to 0.3±0.2 kcal/mol. We found that the MP2/aug-cc-pVTZ adiabatic vibration energy for the reaction (−2.4 kcal/mol) agrees well with the experimental value −(2.2–2.6) kcal/mol. Rate constants calculated with the zeroth-order interpolated variational transition state (IVTST-0) method are in good agreement with experiment. In general, the theoretical rate constants differ from experiment by, at most, a factor of 2.6. |
| |
Keywords: | Abstraction reaction Ethane Chlorine Ab initio Rate constants |
本文献已被 ScienceDirect 等数据库收录! |
|