Spectral distribution of CO/sub 2/ vibrational states produced by collisions with fast hydrogen atoms from laser photolysis of HBr

Journal Article · Tue Mar 15 04:00:00 EST 1983 · J. Chem. Phys.; (United States)

OSTI ID:5636609

Chu, J O; Flynn, G W; Weston, Jr, R E

193 nm photofragmentation of HBr molecules in HBr/CO/sub 2/ mixtures produces energetic (approx.2.5 eV) hydrogen atoms which vibrationally excite CO/sub 2/ molecules via an inelastic translation-vibration/rotation (T-V/R) energy exchange process. Prompt infrared emission in the 4.3 ..mu..m region has been wavelength resolved, and the spectral energy distribution associated with the excited CO/sub 2/ product was measured. The emission profile is strongly red shifted from the spectral region of the ..nu../sub 3/ (00/sup 0/1--00/sup 0/0) fundamental transition indicating that these energetic collisions preferentially produce combination and overtone levels with oscillator strength in the 4.3 ..mu..m region. Cold gas filter studies show that significant emission originates from CO/sub 2/ bend--stretch excitation compared to pure stretching excitation. Approximately 15% of the emission is due to the 01/sup 1/1--01/sup 1/0 transition while the remaining fluorescence has contributions from levels above the 01/sup 1/1 state. The data are in qualitative agreement with theoretical calculations on O/CO/sub 2/ collisions employing either quasiclassical trajectory or infinite order sudden methods, but do not agree with predictions based upon either (harmonic oscillator) breathing sphere theory or statistical theory.

• Research Organization: Department of Chemistry and Columbia Radiation Laboratory, Columbia University, New York, New York 10027
• OSTI ID: 5636609
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 78:6; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COLLISIONS
DECOMPOSITION
ELEMENTS
EMISSION SPECTRA
ENERGY LEVELS
ENERGY TRANSFER
EXCITED STATES
HYDROBROMIC ACID
HYDROGEN
HYDROGEN COMPOUNDS
INFRARED SPECTRA
INORGANIC ACIDS
MOLECULE COLLISIONS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
SPECTRA
VIBRATIONAL STATES