16812-19-4Relevant articles and documents
Rate Constants and Arrhenius Functions for Hydrogen Atom Transfer from tert-Butyl Thiol to Primary Alkyl Radicals
Newcomb, Martin,Glenn, Anne G.,Manek, M. Beata
, p. 4603 - 4606 (1989)
The radical clock method was used to determine rate constants for hydrogen atom transfer from t-BuSH to primary alkyl radicals over the temperature range -45 to 50 deg C.Three clocks, cyclization of the 5-hexenyl radical (3a), ring opening of the cyclopropylcarbinyl radical (3b), and rearrangement of the 2,2-dimethyl-3-butenyl radical (3c), were used in THF, and 3a was used in toluene.Arrhenius functions for the two studies with 3a and the one with 3b were quite similar, and the Arrhenius function for 3c, when adjusted for direct comparison to reactions with simple primary radicals, was also similar.Combining the results from 3a and 3b in THF gave an Arrhenius function for hydrogen atom transfer from t-BuSH to primary radicals of log(k/M-1 s-1) = (8.37 +/- 0.08) - (2.00 +/- 0.09)/2.3RT; the calculated rate constant at 25 deg C is 8.0 * 106 M-1 s-1.This study ultimately relates the t-BuSH rate constants to those for hydrogen atom transfer to primary radicals from both Bu3SnH and PhSH and serves to compare the latter two sets of kinetic data; it also demonstrates that the fast radical clock reactions of 3a and 3b are calibrated against equivalent standards.
Kinetics of Intramolecular Alkyl Radical Attack on Sulfur in Disulfides and Thioesters
Beckwith, Athelstan L. J.,Duggan, Sandhya A. M.
, p. 1509 - 1518 (2007/10/02)
The 4-(alkyldithio)butyl radicals 8a and c, and the 4-(phenyldithio)butyl radical 8b, generated from the corresponding esters of N-hydroxypyridine-2(1H)-thione, undergo fast exo-cyclisation by SHi attack at sulfur.Similarly, the 5-(alkyldithio)pentyl radical 8d undergoes 1,6-ring formation.The rate constants for cyclisation were determined by photolysis of the radical precursors in the presence of appropriate thiols.Butyl and pentyl radicals bearing ω-acetylthio or ω-benzoylthio substituents also undergo ring closure but much more slowly.The kinetics of these intramolecular SH2 reactions are discussed and compared with those for the intermolecular attack of hexyl radicals on diphenyl disulfide and on dibutyl disulfide.
