Reactions of methyl radicals. V. Hydrogen abstraction from hydrogen sulfide

Abstract

Hydrogen abstraction from H₂S by CH₃ radicals, produced by the photolysis of azomethane, has been studied in the temperature range 334-432 K. The rate constant, based on the value 10^13.34 cm³ mol^-1 s^-1 for the recombination of CH₃ radicals, is given by

log k₄ = (11.00 ± 0.01) - (8760 ± 80)/19.145T

where k₄ is in cm³ mol^-1 s^-1 and E is in J mol^-1.

The previous data reported for this reaction are discussed and best values for its Arrhenius parameters are recommended. The results indicate that CH₃ radicals react faster than CF₃ radicals with H₂S; this confirms the importance of polar effects in the hydrogen abstraction reactions of CF₃ radicals.