The influence of the temperature on electron attachment to some Br-substituted alkanes

Thermal electron attachment rate coefficients and activation energies for CH3CH2Br, CH3CH2CH2Br, CH3CHBrCH3, CF3CHBrCH3, CH3(CH2)2CH2Br and CH2F(CH2)2CH2Br have been measured using the Pulsed Townsend technique over the temperature range (298–378) K. The corresponding rate coefficients (k’s) at 298 K were equal to 9.3 ± 2.10 × 10−13, 2.9 ± 0.20 × 10−12, 2.7 ± 0.07 × 10−12, 1.1 ± 0.06 × 10−9, 6.6 ± 1.10 × 10−12 and 2.3 ± 0.3 × 10−10 cm3s−1, respectively. Activation energies (Ea’s) were determined from the fit of the Arrhenius function to the experimental points and were found to be equal to 0.35 ± 0.002, 0.35 ± 0.004, 0.31 ± 0.004, 0.19 ± 0.002, 0.33 ± 0.006 and 0.22 ± 0.002 eV, respectively for CH3CH2Br, CH3CH2CH2Br, CH3CHBrCH3, CF3CHBrCH3, CH3(CH2)2CH2Br and CH2F(CH2)2CH2Br molecules.