The Direct Oxidizing Mechanism for the Reaction of Ozone and Phenol: A DFT Study

Abstract

Using DFT/6-31+G (d, p) method, the structure of phenol are gained in the global optimization and properties were theoretically studied. The atomic electric charges, activation of reaction and thermodynamics parameters are obtained. The calculation shows that benzene ring in phenol tends to have electrophonic attacking substitution reaction O3 directly and form catechol and hydroquinol. The calculation of thermodynamics properties indicate that two pathways are exothermic reactions, and the Gibbs free energies (ΔG) are always less than zero, two reactions are easily occurred spontaneously. Dynamics calculations show that there is only one transition state in each reaction; through vibrational analysis we confirm the transition state. After corrected single point energy, we find that the reaction activation energies of the two reactions are small (Ea1=4.48kcal/mol and Ea2=2.87kal/mol), indicating that ortho-position and para-position products exist simultaneously, which is in accordance with the thermodynamics calculation result.