Mechanism of sulfide oxidations by peroxymonocarbonate

Citation
Da. Bennett et al., Mechanism of sulfide oxidations by peroxymonocarbonate, INORG CHEM, 40(13), 2001, pp. 2996-3001
Citations number
15
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
INORGANIC CHEMISTRY
ISSN journal
00201669 → ACNP
Volume
40
Issue
13
Year of publication
2001
Pages
2996 - 3001
Database
ISI
SICI code
0020-1669(20010618)40:13<2996:MOSOBP>2.0.ZU;2-Y
Abstract
A detailed mechanism for the oxidation of aryl sulfides by peroxymonocarbon ate ion in cosolvent/water media is described. Kinetic studies were perform ed to characterize the transition state, including a Hammett correlation an d variation of solvent composition, The results are consistent with a charg e-separated transition state relative to the reactants, with an increaser o f positive charge on the sulfur following nucleophilic attack-of the sulfid e at the electrophilic oxygen of peroxymonocarbonate. In addition, an avera ge solvent isotope effect of 1.5 +/- 0.2 for most aryl sulfide oxidations i s consistent with proton transfer in the transition state of the rate-deter mining step. Activation parameters for oxidation of ethyl phenyl sulfide in tert-butyl alcohol/water are;reported. From the pH dependence of oxidation rates and C-13 NMR equilibrium experiments, the estimated pK(a) of peroxym onocarbonate was found to be similar to 10.6.