Measuring the rate constant of the reaction between chlorine atoms and CHF2Br by Cl atom resonance fluorescence

Abstract

The rate constant of the reaction between Cl atoms and CHF 2 Br has been measured by chlorine atom resonance fluorescence in a flow reactor at temperatures of 295-368 K and a pressure of ~1.5 Torr. Lin ing the inner surface of the reactor with F 32L fluoroplastic makes the rate of the heterogeneous loss of chlo rine atoms very low (k het ≤ 5 s -1 ). The rate constant of the reaction is given by the formula k = (4.23 ± 0.13) × 10 -12 e (-15.56 ± 1.58)/RT cm 3 molecule -1 s -1 (with the activation energy in kJ/mol units). The possible role of this reaction in the extinguishing of fires producing high concentrations of chlorine atoms is discussed.