Capture of Thermal Electrons by Oxygen

Permanent capture of thermal electrons by O₂ to form O₂⁻ ions requires the participation of a third body in the collision process to provide a dynamical channel for stabilization. The effectiveness of H₂O and C₂H₄ as stabilizing agents in three‐(C₂H₄–O₂–H₂O) and two‐(C₂H₄–O₂) component mixtures has been investigated. The results are analyzed through the following three‐body reaction scheme: $$\begin{array}{c}\mathrm{e+}{\mathrm{O}}_2+{\mathrm{O}}_2\to {\displaystyle {lim}^{k_1}}{\mathrm{O}}_2^{-}+{\mathrm{O}}_2+\mathrm{energy},\\ \mathrm{e+}{\mathrm{O}}_2+{\mathrm{H}}_2\mathrm{O}\to {\displaystyle {lim}^{k_2}}{\mathrm{O}}_2^{-}+{\mathrm{H}}_2\mathrm{O}+\mathrm{energy},\\ \mathrm{e+}{\mathrm{O}}_2+{\mathrm{C}}_2{\mathrm{H}}_4\to {\displaystyle {lim}^{k_3}}{\mathrm{O}}_2^{-}+{\mathrm{C}}_2{\mathrm{H}}_4+\mathrm{energy},\end{array}$$ and the rate constants k₁, k₂, and k₃ are equal to 0.20±0.02 [J. L. Pack and A. V. Phelps, J. Chem. Phys. 44, 1870 (1966); 45, 4316 (1966)], 1.4±0.5, and 0.34±0.04×10⁻²⁹ cm⁶ sec⁻¹, respectively.