Using the density functional theory (DFT), the reaction mechanism of ClF₃O and C₃H₈ to produce propane radical or propane was studied. At B3PW91/6-311＋＋G(d,p) level, the geometries of all species (reactants, intermediates, transition states and products) of 9 different reaction paths were optimized and the vibration frequencies as well as zero point vibration energies (ZPVE) were also calculated. The activation energies of the reactions were calculated with the results of ZPVE, and the reaction constants, using transition state theory, at room temperature and standard concentration were also calculated. The calculated results suggest that the reaction of ClF₃O and C₃H₈ can produce C₃H₇ radical, HF and C1F₂O or produce C₃H₇OH and ClF₃ through different paths. The main path of the reaction is ClF₃O＋C₃H₈→TS4→M2＋ HF＋ClF₂O with the activation energy only 7.54 kJ/mol and reaction constant k₄＝0.153×10⁶ mol^－1•dm³•s^－1.

Key words: chlorine trifluoride oxide, propane, density functional theory, reaction mechanism