Measurement of Rate Constants of Elementary Gas Reactions of Importance to Upper Atmosphere and Combustion Systems
Final technical rept. 1 Sep 80-28 Feb 85
PITTSBURGH UNIV PA DEPT OF CHEMISTRY
Pagination or Media Count:
The vibrational energy transfer of highly excited HCl and HF was studied by the infrared chemiluminescence method in a series of five papers. HClv or 7 and HFv 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 v2 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.
- Inorganic Chemistry
- Atomic and Molecular Physics and Spectroscopy