ATMOSPHERIC CHEMISTRY OF FCOX RADICALS - KINETIC AND MECHANISTIC STUDY OF THE FC(O)O-2+NO2 REACTION

A pulse radiolysis system was used to study the kinetics of the reacti on of FC(O)O-2 radicals with NO2. By monitoring the rate of the decay of NO2 using its absorption at 400 nm the reaction rate constant was d etermined to be (5.5 +/- 0.6) x 10(-12) cm(3) molecule(-1) s(-1) at 29 6 K and 500-1000 mbar pressure of SF6 diluent. A long path length Four ier transform infrared spectrometer was used to investigate the therma l stability of the product FC(O)O2NO2. The rate of thermal decompositi on of FC(O)O2NO2 was independent of the total pressure of N-2 diluent over the range 100-700 torr and was fit by the expression k(-3) = 6.0 x 10(16) exp(-14150/T) s(-1). The results are discussed in the context of the atmospheric chemistry of FCOx radicals. (C) 1995 John Wiley an d Sons, Inc.