Solvent effects on an SN2 reaction profile

The polarizable continuum model has been used to evaluate the solvent effects on the energetics of the Cl−+CH3Cl → ClCH3+Cl− SN2 reaction. Both geometry relaxation and harmonic vibrational energies have been considered, applying a recent algorithm for the analytical evaluation of second energy derivatives in solution. The results at the density functional level, using a recently proposed hybrid density functional, agree well with high-level post-Hartree–Fock calculations and with experimental data.