The protonation of three-membered ring molecules Theab initio SCF versus the electrostatic picture of the proton approach

The protonation processes for eight three-membered ring molecules have been investigated using the SCF LCAO MO method with Gaussian basis sets and the results are compared with those obtained at the first order approximation, i.e. the electrostatic approximation. The electrostatic results are linearly connected with the SCF ones and are sufficient to get an ordering of the protonation energies in different chemical sites and to obtain reliable representations of the proton approaching paths.