A Theoretical Investigation of the Reaction Mechanism and Kinetics of Hexafluoropropylene (HFP) With Ozone in the Presence of Water

ABSTRACT

A detailed theoretical investigation was conducted to elucidate the reaction mechanism and kinetics of hexafluoropropylene (HFP, CF ₃ CF = CF ₂ ) with ozone (O ₃ ), with and without the catalytic influence of water. Quantum chemical calculations were conducted using the M06‐2X/6–311+G(d,p) theoretical framework. The mechanistic analysis revealed that ozone adds to C = C of HFP, forming a primary ozonide that undergoes rapid decomposition to generate Criegee intermediates. The presence of water facilitates the reaction through hydrogen bonding and catalytic stabilization of intermediates significantly enhancing the overall reactivity. Kinetic parameters were computed using canonical transition state theory, yielding rate constants of 4.2 × 10 ⁻¹⁵ cm ³  molecule ⁻¹  s ⁻¹ for the water‐catalyzed pathway and 8.7 × 10 ⁻²⁰ cm ³  molecule ⁻¹  s ⁻¹ for the non‐catalyzed gas‐phase reaction. Additionally, the non‐catalyzed reaction in a solvent‐like environment was modeled, resulting in an increased rate constant of 2.5 × 10 ⁻¹⁸ cm ³  molecule ⁻¹  s ⁻¹ , highlighting the role of solvation in enhancing reactivity. The global warming potential (GWP) and atmospheric lifetimes have also been assessed.