Rate of the resonant energy-transfer reaction between O/sub 2/(/sup 1/. delta. /sub g/) and HOO

Journal Article · Thu Feb 17 04:00:00 EST 1983 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100227a022· OSTI ID:5862230

Podolske, J R; Johnston, H S

Photolysis of ozone at 253.7 nm in a flow system with helium carrier gas was performed, both without and with added water vapor, and steady-state ozone concentrations were measured by ultraviolet absorption at 315.0 nm. O/sub 2/(/sup 1/..delta../sub g/) is a primary product of UV ozone photolysis, and in a pure ozone system each O/sub 2/(/sup 1/..delta..) is responsible for the destruction of two additional ozone molecules. With water present, the O(/sup 1/..delta..) formed by O/sub 3/ photolysis reacts with H/sub 2/O to form hydroxyl radicals, and these radicals initiate an ozone-destroying chain reaction carried by HO and HOO radicals. The experimental results upon addition of water differed qualitatively from predictions based on the 1981 reaction set, but these differences could be explained in terms of inhibition of O/sub 2/(/sup 1/..delta..) destruction of ozone by way of HOO quenching of O/sub 2/(/sup 1/..delta..): HOO(/sup 2/A'') + O/sub 2/(/sup 1/..delta../sub g/) ..-->.. HOO(/sup 2/A', ..nu../sub 3/=1) + O/sub 2/. An experimental study under a variety of conditions and the interpretation of the data indicate this rate constant to be (3.3 +/- 1.6) x 10/sup 11/ cm/sup 3/ molecule/sup -1/ s/sup -1/. The sensitivity of this result to the uncertainty in the rate constant for radical termination (HO + HOO) and vice versa were also investigated.

• Research Organization: Univ. of California, Berkeley
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5862230
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 87:4; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
ABSORPTION SPECTROSCOPY
CHEMICAL REACTIONS
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY TRANSFER
FLUIDS
GASES
HELIUM
HYDROXYL RADICALS
NONMETALS
OZONE
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
QUENCHING
RADIATIONS
RADICALS
RARE GASES
SENSITIVITY ANALYSIS
SPECTROSCOPY
ULTRAVIOLET RADIATION
VAPORS
WATER VAPOR