Infrared emission from the CF3+NO2 reaction

The reaction of the CF3 radical with NO2 has been investigated by using time-resolved FTIR emission spectroscopy. Strong infrared emission has been attributed to products, CF2O and FNO, excited in the ν2 and ν1 modes, respectively. The direct one-step production pathway 1a is suggested as a major reaction channel: CF3 + NO2 → CF2O + FNO, ΔH°298 = -267 kJ mol-1 (1a); → CF2O + F + NO, ΔH°298 = -31 kJ mol-1 (1b). The rate constant for reaction 1 was measured to be (2.4 ± 0.5) × 10-11 cm3 molecule-1 s-1. The F atom formation pathway 1b is the minor channel: the relative branching ratio of reactions 1a and 1b was estimated as 1 : 0.015. The formation of the FON isomer formed via a five-center intermediate is discussed as a possible carrier of an unidentified emission band near 1880 cm-1. The CF3O + NO reaction was investigated by the same technique. Lower emission intensities from the same reaction products were observed, with proportionally less vibrational excitation in the CF2O product

Infrared emission from the reaction of CHF ((X)over-tilde-(1)A') with NO

Infrared emission has been observed from the reaction of the CHF (X̃1A′) radical with NO (X2Π). The carbene radical was formed by infrared multiphoton dissociation (IRMPD) of either the CH2FCl or the CH2F2 precursor, and emission in the 1850-4500-cm-1 region was observed by a time-resolved Fourier transform infrared (FTIR) technique. Emissions have been identified from the HF product of the reaction and from species produced by the subsequent reaction of the NCO radical product with NO. The HF was found to possess more than a statistical share of the available energy in vibration. Addition of D2 to the system results in DF formed from the reaction of F atoms, and comparison of the HF/DF emission intensities has allowed the relative branching ratio of the CHF + NO reaction forming HF and F products to be 0.6 ± 0.04:0.4 ± 0.03. © 1996 American Chemical Society