Effect of solvation on ozonolysis reaction intermediates and transition states

Electrostatic solvent effects on the ozonolysis of ethylene have been inves tigated using correlated ab initio and density functional approaches. We us e a simple polarizable continuum model for the solvent. It allows us to eva luate the medium effect on both the electronic and nuclear structure of the chemical species involved in the reaction. The computations confirm that b asically the reaction proceeds through the Criegee mechanism. However, form ation of the van der Waals complexes ethylene/ozone and carbonyl oxide/form aldehyde also appears to play a role. All the calculated species are stabil ized with respect to the reactants except the transition state correspondin g to the primary ozonide formation. In general, electrostatic solvent effec ts are relatively small for activation barriers of single reaction steps an d more substantial for the corresponding reaction energies. Moreover, the m edium significantly modifies the structure of some species for which polari zation effects are crucial.