A theoretic study of halomethanes hydrogen atom transfer reactions by methyl radicals

ELSEVIER SCIENCE BV

Lugar: Amsterdan - Holanda; Año: 2000 vol. 507 p. 25 - 25

h2>Abstract The kinetics of hydrogen atom transfer reactions from chloro?fluoro methanes (CFH3, CF2H2, CF3H, CClH3, CCl2H2 and CCl3H) by methyl radical (CH3.) was studied using ab initio calculations. The transition states were determined at the HF level of theory with the 3-21G* and 6-31G** basis sets. The activation energies calculated for the hydrogen abstraction reactions were in reasonably good agreement with the experimental values when they were corrected taking into account the correlation energy contribution on reactants and transition states. Therefore, single point MP2 calculations were carried out on the geometries previously optimized at the UHF-RHF/6-31G**//3-21G* level. For a better description of the contributing factors to the activation entropy, the internal rotation co