Anharmonic effect of the unimolecular dissociation of CF3CX2O (X=F, H) Radicals

The C-C bond scission of the three fluorinated ethoxy radicals CF 3 CF 2 O, CF 3 CFHO, CF 3 CH 2 O has been investigated using YL (Yao and Lin) method.Anharmonic and harmonic rate constants have been calculated for the reactions.In the canonical system of the three reactions at 1 atm pressure, the anharmonic (k 1 ) and harmonic (k 2 ) rate constants of the unimolecular decomposition reactions are k 1 (300K)=6.35×10 6s -1 and k 2 (300K) =7.05×10 6 s -1 for CF 3 CF 2 O radical, k 1 (300K) =3.79×10 3 s -1 and k 2 (300K)=3.88×10 3s -1 for CF 3 CFHO radical, and k 1 (300K)=6.34×10 - s -1 and k 2 (300K)=4.29×10-2 s -1 for CF 3 CH 2 O radical, respectively.The anharmonic effects on the decomposition reactions have also been examined.The different rate constants indicate that the anharmonic effect has most significant contributions to the decomposition reaction of CF 3 CFHO radical, while the anharmonic effect has least contributions to the decomposition reaction of CF 3 CF 2 O radical.It has also found that higher symmetry of the reactants results in less anharmonic effects on the decomposition reactions.