Multiple-paths hydrogen abstraction reactions of fluorine -with CH_3OH have been investigated at the MP2 (full)/6-311 + + g(d, p) level. The potential energy surfaces (PES) for H-abstraction reaction from carbon atom and oxygen atom were given respectively. The results indicate that there is only one minimum energy path for hydrogen abstraction from carbon atom, while multiple paths were found for hydrogen abstraction from oxygen atom. All the stationary structures, frequencies as well as PES sketch of all channels were given, in which the dominant channel is by a five-member ring transition state. The calculated heat of reaction is 170.62 kj/mol for channel 1, 119.41 kJ/ mol for branch channel 6. The results are in good agreement with experimental data.

Key words: FLUORINE, METHANOL, POTENTIAL ENERGY SURFACES, REACTION MECHANISM, COLLISON, TRANSITION STATE THEORY, FREE RADICAL REACTION