Experimental and theoretical studies of the reaction between CF 3 and NO 2 at 298 K

Abstract

The title reaction has been studied by pulse radiolysis combined with time-resolved infrared diode laser spectroscopy. The kinetics of CF 3 were analysed taking into account the two competing reactions CF 3+ CF 3+M → C 2F 6+M (1) and CF 3+NO 2 → CF 2O+FNO (2a). Based on studies of the yield and kinetics of CF 3 we determined values of the absorption cross section, σ(CF 3)=(1.96±0.20)×10 −17 cm 2 molecule −1 at 1263.567 cm −1 and the bimolecular rate constant, k 1=(1.04±0.12)×10 −11 cm 3 molecule −1 s −1 with a bath gas pressure of 20 mbar at 298 K. Reaction (2a) was studied under pseudo-first-order conditions and the value of k 2a=(1.53±0.20)×10 −11 cm 3 molecule −1 s −1 was found to be independent of bath gas pressure in the range 4–22 mbar. Based on the characteristic absorption spectra of the products, the branching ratio of reaction (2a) was found to be 0.95.