If one compares BDEs with IPs and PAs, i.e. the reaction
enthalpies of the first steps in the two-step mechanisms,
HAT presents the thermodynamically preferred pathway. Contrary
to gas-phase, PAs are significantly lower than IPs. Interestingly, for
pyridoxal, IEF–PCM B3LYP, as well as SMD B3LYP calculations
provide similar BDE and PA values.