Rate Enhancement Resulting from Reagent Vibrational Excitation as Estimated by the BEBO Method.
Abstract
The bond-energy bond-order (BEBO) method for calculating rate coefficients and activation energies on the basis of molecular properties has been applied to estimating rate coefficients and activation energies for H-transfer reactions involving vibrationally excited reactants. The reactions examined included Br + H2(v equals 0, 1) equals H + HBr, Br + HC1(v equals 0, 1, 2) equals C1 + HBr, and F + HC1(v equals 0, 1) equals C1 + HF. Good agreement was obtained between the computed BEBO rate coefficients and published rate coefficients. It is important to note that the rate enhancement resulting from vibrational excitation could be explained for most of the reactions as being largely caused by the lower bond dissociation energy of the vibrationally excited reagent. Because of the significance of vibrational de-excitation rates in chemical lasers, BEBO computations were made for HF and DF de-excitation by reactions with H, D, F, and other atoms. The highest computed de-excitation rate coefficients were those involving reactions with F-atoms. Reagent vibrational excitation to v equals 10 was examined. Computations were also made to estimate rate coefficients for several possible deuterium isotope separation methods based on the use of vibrationally excited reactants. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1981
- Accession Number
- ADA106431
Entities
People
- Norman Cohen
- Stanley W. Mayer
Organizations
- The Aerospace Corporation