In situ radical detection under very low pressure photolysis conditions using resonance-enhanced multiphoton ionization. Kinetics of CF/sub 3/ radicals produced from IR multiphoton dissociation of hexafluoroacetone

Journal Article · Thu Sep 22 00:00:00 EDT 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100330a006· OSTI ID:6220057

Robertson, R M; Golden, D M; Rossi, M J

Resonance-enhanced multiphoton ionization (REMPI) and mass spectrometry have been used to measure the kinetics of CF/sub 3/ radicals inside a very low pressure photolysis (VLP/Phi/) cell. Infrared multiphoton dissociation (IRMPD) of hexafluoroacetone (HFA) is used to generate the radicals according to CF/sub 3/COOF/sub 3/ ..-->.. CF/sub 3/ + CF/sub 3/CO. REMPI spectra of vibrationally hot and thermalized CF/sub 3/ radicals are presented. The absolute density of CF/sub 3/ in the reactor is determined from the REMPI signal by using mass spectral data. This puts the calibration on the absolute basis necessary to treat competing unimolecular and bimolecular reactions of CF/sub 3/ free radical. Measuring the CT/sub 3/ density as a function of time between pulses of the IR laser and of HFA flow rate allows direct determination of the first- and second-order loss rates for CF/sub 3/. The CF/sub 3/CO radical is stable under the authors conditions and engages in recombination back to HFA at higher radical densities.

• Research Organization: SRI International, Menlo Park, CA (USA)
• OSTI ID: 6220057
• Journal Information: J. Phys. Chem.; (United States), Vol. 92:19
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACETONE
DISSOCIATION
FLUORINATED ALIPHATIC HYDROCARBONS
CHEMICAL REACTIONS
METHYL RADICALS
CHEMICAL REACTION KINETICS
INFRARED RADIATION
MULTI-PHOTON PROCESSES
PHOTOIONIZATION
PHOTOLYSIS
RESONANCE ABSORPTION
ABSORPTION
ALKYL RADICALS
DECOMPOSITION
ELECTROMAGNETIC RADIATION
HALOGENATED ALIPHATIC HYDROCARBONS
IONIZATION
KETONES
KINETICS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
RADIATIONS
RADICALS
REACTION KINETICS
400500* - Photochemistry