Thermal Decomposition of Hsub3O(-) Produced in Reaction of OH(-) with Hsub2CO
Abstract
The ion-molecule reaction OH(-) + Hsub2CO yields Hsub3O(-) + CO has been studied at 300 K with isotopic labeling of reactants. The Hsub3O(-) product is only observed in small abundance because the ion dissociates into OH(-) + Hsub2 upon multiple collisions in a helium buffer gas. Without isotopic labeling, the pseudo-first-order kinetics plots for the reactions of OH(-) with Hsub2CO and OD(-) + Dsub2CO were found to be curved as a result of the regeneration of OH(-) or OD(-) reactant. A scavenger technique was used to remove the Hsub3O(-) (or Dsub3O(-) produced prior to dissociation, to reveal the true first-order attenuation of OH(-) (or OD(-)) in reaction with Hsub2CO (or Dsub2CO). The rate constant for the OH(-) + Hsub2CO reaction is 7.6 x 10 to the minus 10th power cc s(-1), and for OD(-1) + Dsub2CO, is 5.7 x 10 to the minus 10th power cc s(-1). For the isotopically mixed cases OH(-) + Dsub2CO and OD(-) + Hsub2CO, the rate constants are equal to 1.3 x 10 to the minus 9th power cc s(-1), about twice as large as those for the reactions involving only a single hydrogen isotope, indicating that isotopic exchange is an important process. The rate constants for the thermal dissociation of Hsub3O(-) and Dsub3O(-) in helium were found to the 1.6 x 10 to the minus 12th power and 1.1 x 10 to the minus 12th cc s(-1), respectively, within a factor of 2. The results are discussed in terms of other thermal dissociation reactions of ions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1994
- Accession Number
- ADA277470
Entities
People
- Albert A Viggiano
- Amy E. Miller
- Eileen R. Brown
- Emmett A. Sutton
- John F. Paulson
- Robert A. Morris
- Thomas M Miller
Organizations
- Phillips Laboratory