Millimeter-wave observations of vibrationally excited SO and CS produced by laser photolysis

Journal Article · Mon Dec 15 04:00:00 EST 1986 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.451398· OSTI ID:7222430

Kolbe, W F; Leskovar, B

The methods of steady-state and pulsed millimeter-wave rotational spectroscopy were used to probe the vibrationally excited products, CS and SO produced in the laser photolysis of CS/sub 2/ and SO/sub 2/ at 193 nm. The time dependence of the vibrational populations was measured for CS up to v = 8 and for SO up to v = 5. For CS, a Boltzmann-like population distribution was found with a vibrational temperature of 5795 K corresponding to a vibrational energy of 9.8 kcal mol/sup -1/. In the case of SO, significant excitation was observed only for the states v = 0, 1 and 2 with v = 2 having the largest initial population. A small percentage of the SO molecules were found in v = 5. The precursor gases were diluted in Ar to enhance the ratio of rotational to vibrational relaxation times. Because rotational transitions were probed, it was necessary to wait for rotational equilibrium to be established before making the measurements. As a result, the vibrational populations may have been partially relaxed at the time of measurement. In order to evaluate the extent of relaxation, a discussion of the various relaxation processes is given.

• Research Organization: Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720
• OSTI ID: 7222430
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 85:12; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
CARBON COMPOUNDS
CARBON SULFIDES
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
LASER RADIATION
MICROWAVE SPECTRA
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADIATIONS
ROTATIONAL STATES
SPECTRA
SULFIDES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
ULTRAVIOLET RADIATION
VIBRATIONAL STATES