Very high resolution photofragmentation-translational spectroscopy

Technical Report · Sat Nov 01 04:00:00 EST 1986

OSTI ID:7100996

Wodtke, A M

We have designed and constructed a new higher resolution molecular beam apparatus, specifically for studying laser induced dissociation under collision free conditions. The photochemistry of acetylene at 193 nm has been studied. By finding the maximum release of translational energy of the products C/sub 2/H and H, D/sub 0/(C/sub 2/H-H) was derived with high accuracy and precision. Resolved structure in the product's translational energy distribution sheds lights on the vibronic properties of the C/sub 2/H radical. The heat of formation of the vinyl radical was determined by studying the photodissociation of vinylbromide at 193 nm. The collision free unimolecular decomposition of three nitroalkanes: nitromethane, nitroethane and 2-nitropropane, was investigated using infrared multiphoton dissociation (IRMPD). The isomerization of CH/sub 3/NO/sub 2/ to CH/sub 3/ONO was observed for the first time and raises interesting questions about the primary decomposition pathways of other nitro-containing molecules. Through a novel application of RRKM theory, the barrier height to isomerization was found to be approx.5 kcal/mol lower than the C-N bond energy in nitromethane. 126 refs., 38 figs., 11 tabs.

• Research Organization: California Univ., Berkeley (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7100996
• Report Number(s): LBL-22619; ON: DE87004595
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400500* -- Photochemistry
ACETYLENE
ALKANES
ALKYL RADICALS
ALKYNES
BEAMS
BINDING ENERGY
BROMINE COMPOUNDS
CHEMICAL EXPLOSIVES
CHEMICAL REACTIONS
CHEMISTRY
DISSOCIATION
ENERGY
ENTHALPY
ETHANE
EXPLOSIVES
FORMATION HEAT
HALOGEN COMPOUNDS
HYDROCARBONS
ISOMERIZATION
MEASURING INSTRUMENTS
MOLECULAR BEAMS
NITRO COMPOUNDS
NITROMETHANE
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHYSICAL PROPERTIES
PROPANE
RADICALS
REACTION HEAT
SPECTROMETERS
THERMODYNAMIC PROPERTIES
TIME-OF-FLIGHT SPECTROMETERS
VINYL RADICALS