Studies on density function theory for the F−+CF3SO3CF2CF3SN2 reaction

The reaction mechanism of the sulfur oxygen and/or carbon oxygen bond breaking in sulfonates during nucleophilic substitution has been studied using DFT (B3LYP) method at 6-31G level. Through the analysis of the kinetics and thermodynamics, we conclude that halide ion (F−) easily attacks the sulfur atom of perfluoroalkanesulfonic ester, causing the S–O bond cleavage to give CF3SO2F and −OCF2CF3. In contrast to the S–O bond cleavage it has been found that the C–O bond scission in perfluoroalkanesulfonic ester is difficult to take place. This conclusion is in good agreement with experiment.