Measurement of Rate Constants of Elementary Gas Reactions of Importance to Upper Atmosphere and Combustion Systems
Abstract
The vibrational energy transfer of highly excited HCl and HF was studied by the infrared chemiluminescence method in a series of five papers. HCl(v < or = 7) and HF(v < or = 7) were produced by fast generating reations, e. g. H + IC1 yields (v < or = 7) + I or H +F2 yields (< or = 7) + F in large excess He which relaxes the rotational but not the vibrational excitation. With various added quencher gases, about 200 rate constants for stepwise vibrational energy transfer were measured. They tend to increase rapidly with increasing v, often independent of the vibrational energy defect. For HF (v) + HF (O), self-relaxation, the V-V channel decreases from 55% at v=2 to zero at v > 5 even though the relaxation rate constant rises as v to the 2.7 power. A versatile flow reactor system was built that features three detection methods (laser-induced fluorescence, vacuum u.v. resonance fluorescence, and modulated molecular beam mass spectrometry) plus upstream radical production by IR laser multiphoton decomposition. The NH2 + NO and CH3O + NO2 reactions were studied successfully. The latter was found to have a recombination (CH3ONO2) and disproportionation (CH2O + HNO2) channel and both were measured indirectly. The 18O + NO or O2 isotope exchange reactions were measured, and the results compared with measured and calculated high-pressure limits of the respective recombinations and with NO vibrational relaxation.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 10, 1985
- Accession Number
- ADA158824
Entities
People
- Frederick Kaufman
Organizations
- University of Pittsburgh