Reactions of the O Negative Ion with Hydrogen and the Lower Hydrocarbons

Abstract

The reactions between O–, formed by dissociative attachment to oxygen, and H2, D2, CH4, C2H6, C2H4 and C2H2 have been studied using a drift tube and mass filter. Gas densities ranged over a factor of five about 1017 molecule cm–3 and reduced fields were of the order of 3 × 10–16 V cm2 molecule–1. The reaction with the alkanes gave a single pair of products R + OH–, but the remainder produced both negative ions and free electrons. The following rate constants were measured and with the minor exception of OH– production from C2H4 were found to be substantially independent of the reduced field. [graphic omitted] The reaction with C2H4 also produced OH–, C2H–, C2OH– and C2H3O– at rates of 0.5 to 10, 5, 1.5 and 2 % respectively of the combined rate of the two major channels.

The upper limits for the rates of the reactions of O–3 with the same molecules were two orders of magnitude lower.