Abstract
A theoretical study on the decarboxylation reaction of CH3CO2 radical at the MP2 level of theory has been carried out. It is found that the thermal reaction CH3CO2 → CH3 + CO2 may occur on the 2A′(A′) potential energy surface of CH3CO2 via a reaction barrier of 4.2 kcal/mol at the PMP4/6-311+G(3df,3pd)//MP2/6-311+G(2df,2p) level of theory. Another possible reaction path is the CH3CO2(A′) transform into the CH3CO2(A1) and thus undergo a barrier-less dissociation into the products CH3 + CO2. The thermal rate constants of channel CH3CO2(A′) → CH3 + CO2.were evaluated based on the electronic structure and energy information from the PMP4/6-311+G(3df,3pd)//MP2/6-311+G(2df,2p) level of theory with microcanonical variational transition state theory (μVT) in the temperature range of 200-3000 K. The fitted Arrhenius expression from the forward μVT rate constants within the calculated temperature range is Kμ VT = 2.196 × 1011 T0.294 e(- 2.304 × 103 / T) s- 1. It is also found that the geometry of the CH3CO2 radical is sensitive to the basis set used.
Original language | English |
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Pages (from-to) | 40-45 |
Number of pages | 6 |
Journal | Journal of Molecular Structure: THEOCHEM |
Volume | 854 |
Issue number | 1-3 |
DOIs | |
Publication status | Published - 15 Apr 2008 |