Vibrational Relaxation of H2O by H2, HCl, and H2O at 295K
Abstract
A laser-induced fluorescence method has been used to measure rate constants for vibrational relaxation of the equilibrated v1 and V3 stretching level reservoir, the 2v2 bending overtone level, and the v2 bending level Of H20 by H2 and HCl at 295K. The rate constants for relaxation by H2 were found to be 8.0 +/- 1.1, 29 +/- 4, and 13 +/- 2 x 10(-13) cm3 molecule-1 s-1, respectively. For relaxation by HCl, the rate constants were 8.4 +/- 1.2, 47 +/- 7, and 24 +/- 4 x 10-(12) cm3 molecule-1 s-l, respectively. Relaxation by intermolecular V yield V transfer was experimentally determined to account for <8% of the rate constant for relaxation of the H20 stretching levels by HCl, and was estimated to contribute <16% of the rate constant for relaxation of the bending overtone level. For both collision partners, the H20 stretching levels were relaxed predominantly to the 2v2 level, and the 2v2 level was relaxed predominantly to v2. Following direct laser excitation, the rate constant for relaxation of the equilibrated v1 + v2 and v3 + v2 combination vibrational levels Of H20 by H20 was measured to be 1.6 +/- 0.2 x 10-10 cm3 molecule-1 s-1. Direct relaxation to the v1 and V3 fundamental levels was experimentally determined to account for <40% of the relaxation rate constant.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 16, 1992
- Accession Number
- ADA252800
Entities
People
- D. E. Masturzo
- P. F. Zittel
Organizations
- The Aerospace Corporation