KINETICS OF THE F-]FNO2+M REACTION STUDIED BY PULSE-RADIOLYSIS COMBINED WITH TIME-RESOLVED IR AND UV SPECTROSCOPY(NO2+M)

The title reaction was initiated by the pulse radiolysis of SF6/NO2 ga s mixtures, and the formation of FNO2 was studied by time-resolved inf rared spectroscopy employing strong rotational transitions within the nu(1) and nu(4) bands of FNO2. The pressure dependence of the formatio n kinetics was studied with SF6 pressures of 5-1000 mbar at 298 K. Com parative 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 o bserved pressure dependence is represented in terms of a fall-off curv e with the following values of the limiting high- and low-pressure rat e coefficients, k(rec,proportional to) = (2.1 +/- 1.0)x 10(10) (T/300) (0.5) M(-1) s(-1) and K-rec,K-0/[SF6] = (3.8 +/- 1.8) x 10(12) (T/300) (-24) M(-2) S-1 in the temperature rang 200-400 K, and with a broadeni ng factor, F-cent = 0.587X (T/300>(-0.32).