FTIR-SPECTROSCOPIC STUDY OF REACTIONS OF FCO AND FC(O)OO RADICALS IN THE PRESENCE OF O-2 AND NO2

Steady-state photolysis of oxalylfluoride (FC(O)C(O)F) together with F TIR-spectroscopy has been used to investigate the reactions of FCO and FC(O)OO radicals in the presence of O-2 and NO2. Formation of FCO rad icals has been identified as the main photodissociation process of oxa lylfluoride at lambda = 254 nm. However, a quantum yield of phi = 0.11 +/- 0.02 was attributed to the direct formation of CF2O and CO in thi s process. In the presence of O-2, the products of reactions of FC(O)O -x(x = 0, 1, 2) radicals were bis-fluoroformylperoxide (FC(O)OOC(O)F) and bis-fluoroformyltrioxide (FC(O)OOOC(O)F), as well as CF2O, CO and CO2. Addition of NO2 to the reaction system led to the formation of fl uoroformylperoxynitrate (FC(O)OONO2). The rate constant for the therma l decomposition of fluoroformylperoxynitrate in the temperature range 275-307 K was measured to be k(T) = 3.5 x 10(16) exp (-13900(-2600)(+1 700)/T) s(-1). For bis-fluoroformyltrioxide, a rate constant for therm al decomposition of 6.0 x 10(-4) s(-1) was measured at temperatures ar ound 250 K. The thermal stability of bis-fluoroformyltrioxide and fluo roformylperoxynitrate is discussed in terms of a comparison with the s tability of similar molecules.