Rate Constants for the Thermal Energy Reactions of H−. with O2, NO, CO, and N2O

The reaction of H− with O2 has been measured in a flowing afterglow system at 278°K. The reaction is found to be associative detachment, H−+O2→HO2+e, with a rate constant 1.2 ± 0.2 × 10−9 cm3/sec. A careful search was carried out for the possible heavy negative ion products, O2−, OH−, O− with negative results. Such products are believed to contribute less than 1% to the reaction if they contribute at all. Also, the reaction H−+N2O→OH−+N2 has a rate constant 1.1 ± 0.3 × 10−9 cm3/sec, the reaction H−+NO→HNO+e has a rate constant 4.6 × 10−10 cm3/sec, and H−+CO→HCO+e has a rate constant 4.6 × 10−10 cm3/sec, and H−+CO→HCO+e has a rate constant ∼5 × 10−11 cm3/sec.