RATES OF REACTION OF SINGLET OXYGEN WITH SULFIDES |
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Authors: | Bruce M Monroe |
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Institution: | Central Research &Development Department,* Experimental Station, E. I. du Pont de Nemours &Company, Wilmington, DE 19898, U.S.A. |
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Abstract: | Abstract—Reaction rate constants for the reaction of singlet oxygen with a series of 24 sulfides in chloroform have been measured by inhibition of the self-sensitized photooxidation of rubrene. The reaction rate constant is sensitive to steric effects, decreasing as the carbons α- to sulfur become more highly substituted. Addition of a methyl group to each of the carbons α- to sulfur decreases the rate constant by about a factor of 10. From a series of p - and m -substituted thioanisoles, a ρ of -1.67 ± 0.09 was found. A much better correlation was found with σ than with σ+ indicating there is no resonance interaction with the reaction center. Typical rate constants are: di- n -butyl sulfide, 2.3 × 107 M -1 s-1; CBZ-L-methionine methyl ester, 1.4 × 107; di-s-butyl sulfide, 1.8 × 106; di- t -butyl sulfide, 1.3 × 105; and thioanisole, 2.3 × 106. |
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