KINETIC-STUDY FOR THE UNIMOLECULAR DISSOCIATION OF CF3H - RRKM AND PST CALCULATIONS ON AN AB-INITIO POTENTIAL-ENERGY SURFACE

Unimolecular dissociations of CF3H into (1) CF2((1)A(1)) + HF, (2) CF3 + H and (3) CF2H + F were studied by means of RRKM and PST calculatio ns on an ab initio potential energy surface. Activation energies for t he three channels (1), (2) and (3) are 73.95, 108.20 and 130.02 kcal/m ol at G2 level, respectively. RRKM and PST calculations show that the reaction rate for channel (1) is significantly faster than that for ch annel (2) at low energy. As the internal energy increases, channel (2) becomes important and, at energies greater than 7.0 eV, competes with channel (1). These results are consistent with recent experimental ob servations.