Flowtube reactor study of the association reactions of CHCl 2 and CCl 3 with O 2 at low pressure

The new flowtube reactor employing dissociative electron attachment to produce radicals and high‐pressure photoionization in the mass spectrometric detection of radicals is described. The system has been applied to a study of the association reactions of CHCl 2 and CCl 3 with O 2 in a great excess of helium at total densities below 10 17 cm −3 over the temperature range 286 to 332 K. Both reactions display a strong negative temperature coefficient. The results can be parameterized in the form k 0 (CHCl 2 + O 2 ) = (4.3 ± 0.2) × 10 −31 ( T /300) −6.7±0.7 cm 6 s −1 , k 0 (CCl 3 + O 2 ) = (2.7 ± 0.2) × 10 −31 ( T /300) −8.7±1.0 cm 6 s −1 . © 1994 John Wiley & Sons, Inc.