The influence of the temperature on electron attachment to some halocontaining molecules

Abstract

Thermal electron attachment rate coefficients for CH 2ClCHClCH 2Cl, CH 2ClCH 2Br, CH 2ClCH 2CH 2Br and CF 2ClCFCl 2 have been measured using the Pulsed Townsend technique over the temperature range T = 298–358 K. The corresponding rate coefficients at 298 K are equal to 1.7(4) × 10 −10, 7.9(15) × 10 −10, 3.4(5) × 10 −10 and 3.1(1) × 10 −8 cm 3 molec. −1 s −1, respectively. With rising temperature we have observed an increase of the rate coefficients k( T), which shows an Arrhenius-type behaviour. Activation energies E a of 0.16(1) eV (CH 2ClCHClCH 2Cl), 0.12(1) eV (CH 2ClCH 2Br), 0.20(1) eV (CH 2ClCH 2CH 2Br) and 0.08(1) eV (CF 2ClCFCl 2) were determined from the fit to the experimental data points with a function ln( k) = ln( A) − E a / k B T.