Kinetics of theF + NO2 + M → FNO2 + M reaction studied by pulse radiolysis combined with time-resolved IR and UV spectroscopy

The title reaction was initiated by the pulse radiolys ofSF6NO2 gas mixtures, and the formation of FNO2 was studied by time-resolved infrared spectroscopy employing strong rotational transitions within theν1 and ν4 bands of FNO2. The pressure dependence of the formation kinetics was studied with SF6 pressures of 5–1000 mbar at 298 K. Comparative studies were carried out by monitoring the decay kinetics of NO2 at 445 nm using pressures of 100–1000 mbar at 295 and 341 K. The observed pressure dependence is represented in terms of a fall-off curve with the following values of the limiting high- and low-pressure rate coefficients,krec,∞ = (2.1 ± 1.0) × 1010 (T/300) 0.15 M−1 s−1 andkrec,0/[SF6] = (3.8 ± 1.8) × 1012 (T/300)−2.4 M−1 s−1 in the temperature range 200–400 K, and with a broadening factor,Fcent = 0.587 × (T/300)−0.32.