Vacuum ultraviolet photochemistry. I. Unimolecular decomposition studies of small hydrocarbon clusters by molecular beam photoionization mass spectrometry; II. Photofragment dynamics study of carbon disulfide by high resolution molecular beam laser photofragment time-of-flight mass spectrometry

Technical Report · Fri Aug 01 00:00:00 EDT 1986

OSTI ID:5228485

Tzeng, W B

The energetic and dissociation dynamics of (C/sub 2/H/sub 4/)/sub 2//sup +/, (C/sub 2/H/sub 4/)/sub 3//sup +/, (C/sub 3/H/sub 6/)/sub 2//sup +/ and (c-C/sub 3/H/sub 6/)/sub 2//sup +/ complexes have been studied by photoionization of neutral van der Waals ethylene dimers and trimers, propylene dimers and cyclopropane dimers. Photoionization efficiency studies of C/sub 2/H/sub 4/, C/sub 3/H/sub 6/ and c-C/sub 3/H/sub 6/ and their clusters yield the ionization energies of (C/sub 2/H/sub 4/)/sub n = 1,2,3/, (C/sub 3/H/sub 6/)/sub n = 1,2/ and (c-C/sub 3/H/sub 6/)/sub n = 1,2/ and the appearance energies of C/sub 3/H/sub 5//sup +/ and C/sub 4/H/sub 7//sup +/ from (C/sub 2/H/sub 4/)/sub 2/. It is concluded that the (C/sub 2/H/sub 4/)/sub 3//sup +/, (C/sub 3/H/sub 6/)/sub 2//sup +/ and (c-C/sub 3/H/sub 6/)/sub 2//sup +/ loose complexes arrange to the common C/sub 6/H/sub 12//sup +/ collision complexes prior to fragmentation by comparing the major product channels in the unimolecular decompositions of these species. A new molecular beam laser photofragment time-of-flight mass spectrometer with rotatable beam source and movable detector has been constructed for studying photofragmentation dynamics of polyatomic molecules. The design considerations detailed assembly, and initial tests of this machine are described. The time-of-flight data of carbon disulfide laser photofragmentation at 193 nm have been taken at various beam source angles and fragment flight path lengths. 394 refs.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5228485
• Report Number(s): IS-T-1260; ON: DE86015768
• Resource Relation: Other Information: Thesis. Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
47 OTHER INSTRUMENTATION
CARBON SULFIDES
MASS SPECTROSCOPY
HYDROCARBONS
DECOMPOSITION
IONIZATION POTENTIAL
MASS SPECTROMETERS
DESIGN
SOLID CLUSTERS
TIME-OF-FLIGHT SPECTROMETERS
DISSOCIATION
MOLECULAR BEAMS
BEAMS
CARBON COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
MEASURING INSTRUMENTS
ORGANIC COMPOUNDS
SPECTROMETERS
SPECTROSCOPY
SULFIDES
SULFUR COMPOUNDS
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)
440300 - Miscellaneous Instruments- (-1989)