Vacuum Ultraviolet Photodissociation and Photoionization of Selected Organosulfur Compounds [Dissertation]

Thesis/Dissertation · Fri Apr 26 00:00:00 EDT 1991

OSTI ID:5760199

Nourbakhsh, Sohail ^[1]

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1. Ames Lab., and Iowa State Univ., Ames, IA (United States)

Using translational spectroscopy and photoionization techniques some organosulfur compounds have been studied in the vacuum ultraviolet spectral region. The photofragmentation technique has been used to obtain data from which bond energies, product quantum state distribution, and energy partitioning among photofragments has been calculated. The photofragmentation experiment also provides information on the secondary photodissociation of primary photofragments such as SSCH₃, SCH₃, and SH. Photoelectron-photoion coincidence (PEPICO) spectra have been measured in the wavelength region of 900-1475 Å. The PEPICO measurements provide detailed information about the unimolecular decomposition dynamics of state or energy-selected CH₃SH⁺ and CH₃SCH₃⁺. The energetic information obtained in the photoionization and photodissociation experiments allows estimates of the ionization energies for some radicals. Finally, a new laser photolysis method has been developed to study free radicals. Intersecting a high repetition rate excimer laser beam with a pulsed molecular beam, a cold pseudocontinuous beam of free radicals can be generated. Combining photoionization with this technique S, CS, CH₃ and SCH₃ photoionization efficiency curves have been obtained.

• Research Organization: Iowa State Univ., Ames, IA (United States); Ames Laboratory (AMES), Ames, IA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5760199
• Report Number(s): IS-T--1529; ON: DE91012025
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
CHEMICAL REACTIONS
DECOMPOSITION
DYNAMIC MASS SPECTROMETERS
ELECTROMAGNETIC RADIATION
EXCIMER LASERS
FAR ULTRAVIOLET RADIATION
GAS LASERS
IONIZATION
LASERS
MASS SPECTROMETERS
MEASURING INSTRUMENTS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOIONIZATION
PHOTOLYSIS
RADIATIONS
SPECTROMETERS
TIME-OF-FLIGHT MASS SPECTROMETERS
TIME-OF-FLIGHT SPECTROMETERS
ULTRAVIOLET RADIATION