Theoretical mechanistic study on the reactions between FO2Â +Â NO and FOÂ +Â NO2

The detailed singlet potential energy surface (PES) of the [FNO3] system is investigated at B3LYP/6-311+G(2d) and CCSD(T)/6-311+G(2d) (single-point) levels. Six isomers and nine transition states are located. Various possible isomerization and dissociation channels are probed in order to explore the reaction mechanism for FO2 + NO. The calculated results indicate that the initial association between FO2 and NO can lead to the adduct FOONO, followed by the concerted F-shift and cleavage of the ON bond leading to the dominant product FNO + O2. The formation of other products, however, is much less feasible due to energy constraints. The three feasible products and reaction pathways are also analyzed for another reaction, FO + NO2, on the basis of the [FNO3] PES. This study may be helpful in understanding the reaction and chemical behaviors of oxygen fluorides.