Fig. 6. Pathways CF3I reacts with the free
radicals in fire flame.
When OH radical and CF3I approach each other, OH radical
interacts with different atoms of the CF3I molecule in
the reaction to form various possible products. As the first reaction
step, the O atom of the OH can directly absorb the F atoms of
CF3I molecule through the transition state TSb1 to form
CF2I· + FOH (P4), with the barrier height of 64.806
kcal·mol−1. When the O atom of the OH attacks the C
atom of CF3I, CF3OH + I (P5) may be
formed through the transition state TSb2. In the process of reaction, O
atom of OH attacks C atom of CF3I, causing it to get rid
of the I atom, and the energy barrier is 41.497
kcal·mol−1. The last reaction step between
CF3I and OH radical is the most likely to occur, with no
intermediate transition state. CF3I directly deatoms I
to generate CF3· + HIO (P7) with a small energy barrier
of 8.267 kcal·mol−1. According to the above
calculation results, the potential energy curve of the reaction path
between CF3I and OH radical is shown in Fig.7 .
The results show that in the CF3I + OH reaction, the I
atom extraction channel may be dominant from the perspective of
kinetics, and CF3I is more likely to generate
CF3 fire-extinguishing radical.