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Studies on the oxygen atom transfer reactions of peroxomonosulfate: Oxidation of glycolic acid
Author(s) -
Shailaja S.,
Ramachandran M. S.
Publication year - 2009
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.20388
Subject(s) - chemistry , glycolic acid , hydrogen peroxide , metal , reaction rate constant , kinetics , nickel , inorganic chemistry , oxygen , peroxide , metal ions in aqueous solution , copper , organic chemistry , lactic acid , genetics , physics , quantum mechanics , bacteria , biology
The kinetics of oxidation of glycolic acid, an α‐hydroxy acid, by peroxomonosulfate (PMS) was studied in the presence of Ni(II) and Cu(II) ions and in acidic pH range 4.05–5.89. The metal glycolate, not the glycolic acid (GLYCA), is oxidized by PMS. The rate is first order in [PMS] and metal ion concentrations. The oxidation of nickel glycolate is zero‐order in [GLYCA] and inverse first order in [H + ]. The increase of [GLYCA] decreases the rate in copper glycolate, and the rate constants initially increase and then remain constant with pH. The results suggest that the metal glycolate ML + reacts with PMS through a metal‐peroxide intermediate, which transforms slowly into a hydroperoxide intermediate by the oxygen atom transfer to hydroxyl group of the chelated GLYCA. The effect of hydrogen ion concentrations on k obs suggests that the structure of the metal‐peroxide intermediates may be different in Ni(II) and Cu(II) glycolates. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 160–167, 2009