Formation, thermal decomposition and atmospheric implications of the CF₂(OH)CF₂OONO₂ and CF₃CF₂OONO₂ peroxynitrates: a theoretical study

Abstract

A SACM/CT study of the CF₂(OH)CF₂OO + NO₂→CF₂(OH)CF₂OONO₂ and CF₃CF₂OO + NO₂→CF₃CF₂OONO₂ recombination reactions and their reverse unimolecular decomposition process was performed. The electronic energy along the reaction pathways was calculated at the G4(MP2) level. High-pressure rate coefficients of 1.53 x 10^-12 (T/300^)0.37 cm³ molecule^-1 s^-1 and 1.79 x 10¹⁶ (T/300)^0.40 exp (-24.4 kcal mol^-1/RT) s^-1 were derived at 200–300 K for the direct and backward reactions of CF₂(OH) CF₂OONO₂, while for CF₃CF₂OONO₂, the expressions 1.01 x 10^-12 (T/300)^0.39 cm³ molecule^-1 s^-1 and 1.05 x 1016 (T/300)<subp>0.44</sup> exp(-23.0 kcal mol^-1/RT) s^-1 were obtained. A decomposition lifetime profile was derived for CF₂(OH)CF₂OONO₂, indicating that it could act as transport and reservoir of CF₂(OH) CF₂OO and NO₂ in the stratosphere.