The gas-phase reaction of CF3 radicals with HCN in the temperature range 333–523 K
Abstract
The reaction of CF3 radicals produced by photolysis of CF3I with HCN has been investigated in the temperature range 333–523 K. The radicals react with HCN by addition followed by a sequence of reactions of which the most important are: CF3+ HCN ⇆ CF3HCN (1,–1), CF3+ CF3HCN → HCF3CNCF3(2), CF3+ CF3HCN → CF3H + CF3CN(3), I + CF3HCN → HI + CF3CN (4) 2 CF3 [graphic omitted] C2F6. Arrhenius parameters for the addition reaction relative to radical recombination were estimated from experiments at conversions [graphic omitted] 3% in the temperature range 333–453 K. The best fit to our experimental results gave log[(A1/A1/2c) cm3/2 mol–1/2 s–1/2]= 4.97 and E1–½Ec= 30.9 kJ mol–1, with systematic estimated errors of up to 0.3 and 2.4 kJ mol–1, respectively. These parameters are compared with those obtained for other addition reactions of these radicals to substrates with a triple bond.