GAS-PHASE HYDROLYSIS OF TRIFLUOROMETHYL CARBONYL HALIDES TO TRIFLUOROACETIC-ACID

The structures, energetics and vibrational features of the transition structures for gas-phase hydrolysis of CF3C(O)X (where X = H, F, or Cl) compounds are described. The activated complexes are four-membered ring structures which involve the addition of the OH bond from water across the CO bond of CF3C(O)X. The calculated activation energies are 54.6, 35.5, and 50.1 kcal mol-1 for CF3C(O)H, CF3C(O)F, and CF3C(O)Cl, respectively. Decomposition of the hydrolysis product, CF3CX(OH)2, into trifluoroacetic acid, CF3C(O)OH, bas been examined, and activation energy barriers are 75.9, 38.5, and 7.6 kcal mol-1, for X = H, F, and Cl, respectively. The present calculations suggest that gas-phase hydrolysis of CF3C(O)H is more likely to form stable CF3CH(OH)2, while CF3C(O)F and CF3C(O)Cl will produce CF3C(O)OH and hydrogen halide.