An electron spin resonance investigation of the structure and formation of sulfinyl radicals: Reaction of peroxyl radicals with thiols

Journal Article · Thu Jan 12 00:00:00 EST 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100338a034· OSTI ID:5447293

Swarts, S G; Becker, D; DeBolt, S; Sevilla, M D ^[1]

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1. Oakland Univ., Rochester, MI (USA)

In this work we present an electron spin resonance investigation of the irradiation of the alkyl mercaptans methyl, n-butyl, and tert-butyl mercaptan and the radioprotective thiols cysteamine and dithiothreitol in a number of aqueous and organic matrices in the present of oxygen. Matrix peroxyl radicals (ROO*) are formed after the irradiation of organic matrices in the presence of oxygen at 77 K. Upon annealing, these react with added thiols to form sulfinyl radicals (RSO*). Evidence for a thiol peroxyl radical (RSOO*) intermediate is found. Hyperfine couplings and g values are reported for the sulfinyl radicals formed from the five thiols investigated. The incorporation of {sup 17}O-labeled oxygen into the RSO* radical confirms that molecular oxygen is the source of the oxygen atom in the radical. The isotropic and parallel anisotropic {sup 17}O couplings indicate slightly less than 0.5 spin density on the oxygen. The couplings and spin densities are compared to those predicted from ab inito molecular orbital calculations for CH{sub 3}SO*. Calculations for the sulfur-peroxyl intermediate, CH{sub 3}SOO*, predict that it will have similar ESR parameters as those predicted for the carbon-centered peroxyl radical, CH{sub 3}OO*.

• OSTI ID: 5447293
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 93:1; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
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38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
PEROXY RADICALS
CHEMICAL REACTIONS
THIOLS
ELECTRON SPIN RESONANCE
LOW TEMPERATURE
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RADIOLYSIS
REACTION INTERMEDIATES
CHEMICAL RADIATION EFFECTS
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DECOMPOSITION
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ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
RADIATION CHEMISTRY
RADIATION EFFECTS
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