Determination of the absorption cross section for CH/sub 3/ at 216. 36 nm and the absolute rate constant for methyl radical recombination over the temperature range 296-577 K
The absorption cross section, sigma, for the CH/sub 3/ transition at 216.36 nm has been measured for a 0.60-nm band-pass. At 298 K, the cross section was determined by comparing the ethane yield, as measured by gas chromatography, with the zero-time CH/sub 3/ absorbance following laser flash photolysis of azomethane at 193 nm. sigma was also measured over the temperature range 298-537 K by a repetitive photolysis method in which a known initial pressure of azomethane was repeatedly photolyzed with ArF laser and the zero-time absorbance determined following each laser pulse. The two room-temperature determinations gave cross sections in good agreement. The limiting high-pressure rate constant (k/sub infinity/) decreases slightly with temperature, and it may be expressed in the form k/sub infinity/ = (4.09 +/- 0.36) x 10/sup -11/ exp((137 +/- 33)/(T/K)) cm/sup 3/ molecule/sup -1/ s/sup -1/ over the temperature range 296-577 K. The quoted errors represent 95% confidence limits. 35 references, 2 figures, 5 tables.
- Research Organization:
- Oxford Univ., England
- OSTI ID:
- 5132630
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 89:11
- Country of Publication:
- United States
- Language:
- English
Similar Records
Recombination of methyl radicals. 1. New data between 1175 and 1750 K in the falloff region
Cl{sub 2}O photochemistry: Ultraviolet/vis absorption spectrum temperature dependence and O({sup 3}P) quantum yield at 193 and 248 nm
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AZO COMPOUNDS
PHOTOLYSIS
METHYL RADICALS
CROSS SECTIONS
RECOMBINATION
ABSORPTION SPECTRA
EXPERIMENTAL DATA
LASERS
MATHEMATICAL MODELS
MEDIUM TEMPERATURE
TEMPERATURE DEPENDENCE
ALKYL RADICALS
CHEMICAL REACTIONS
DATA
DECOMPOSITION
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
RADICALS
SPECTRA
400500* - Photochemistry
400301 - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)