SO/sub 2/(/sup 3/B/sub 1/) photosensitized isomerization of cis- and trans-1,2-dichloroethylene

Journal Article · Wed Dec 31 23:00:00 EST 1975 · Int. J. Chem. Kinet.; (United States)

DOI:https://doi.org/10.1002/kin.550080412· OSTI ID:7230632

Wampler, F B ^[1]; Boettenheim, J W

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1. Los Alamos Scientific Lab., NM

The photolysis of SO/sub 2/ at 3712 A in the presence of the 1,2-dichloroethylenes has been investigated at 22/sup 0/C. The data are consistent with the SO/sub 2/(/sup 3/B/sub 1/) photosensitized isomerization of the 1,2-dichloroethylene isomer. A kinetic treatment of the initial quantum yield data was consistent with the formation of a polarized charge-transfer intermediate whenever SO/sub 2/(/sup 3/B/sub 1/) molecules and one of the 1,2-dichloroethylene isomers collide which ultimately decays unimolecularly to the cis-isomer with a probability of 0.70 +- 0.26 and to the trans-isomer with a 0.37 +- 0.16 probability. Quenching rate constants for removal of SO/sub 2/(/sup 3/B/sub 1/) molecules by cis- and trans-1,2-dichloroethylene have been estimated from quantum yield data and from laser excited phosphorescence lifetimes using an excitation wavelength of 3130 A. Estimates of the quenching rate constant (units of l./mole.sec) are for the cis-isomer, (1.63 +- 0.71) x 10/sup 10/, quantum yield data, and (2.44 +- 0.11) x 10/sup 10/, lifetime data; and for the trans-isomer, (2.59 +- 0.09) x 10/sup 10/, lifetime data, and (2.35 +- 0.89) x 10/sup 10/, quantum yield data. An experimentally determined photostationary composition, (cis-C/sub 2/Cl/sub 2/H/sub 2/)/(trans-C/sub 2/Cl/sub 2/H/sub 2/) = 1.8 +- 0.1, was in good agreement with a value of 2.00 +- 1.15 which was predicted from rate constants derived in this study.

• OSTI ID: 7230632
• Journal Information: Int. J. Chem. Kinet.; (United States), Journal Name: Int. J. Chem. Kinet.; (United States) Vol. 8; ISSN IJCKB
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
DECOMPOSITION
HALOGENATED ALIPHATIC HYDROCARBONS
ISOMERIZATION
KINETICS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PHOTOSENSITIVITY
REACTION KINETICS
SENSITIVITY
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES