Decomposition of N-Chloroglycine in Alkaline Aqueous Solution

Kinetics and Mechanism

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The decomposition kinetics and mechanism of N-chloroglycine (MCG) was studied under very alkaline conditions ([OH-] = 0.01-0.10 M). The absorbance change is consistent with two consecutive first-order processes in the 220-350 nm wavelength range. The first reaction is linearly dependent on [OH-] and interpreted by the formation of a carbanion from MCG in an equilibrium step (KOH) and a subsequent loss of chloride ion from this intermediate: kobs1 = KOH k1 = (6.4 ± 0.1) × 10-2 M-1 s-1, I = 1.0 M (NaClO4), and T = 25.0°C. The second process is assigned to the first-order decomposition of N-oxalylglycine, which is also formed as an intermediate in this system: kobs2 = (1.2 ± 0.1) × 10-3 s-1. Systematic 1H and 13C NMR measurements were performed in order to identify and follow the concentration changes of the reactant, intermediate, and product. It is confirmed that the decomposition proceeds via the formation of glyoxylate ion and produces N-formylglycine as a final product. This compound is stable for an extended period of time but eventually hydrolyses into formate and glycinate ions. A detailed mechanism is postulated which resolves the controversies found in earlier literature results.

Original languageEnglish
Pages (from-to)1282-1291
Number of pages10
JournalChemical Research in Toxicology
Volume28
Issue number6
DOIs
Publication statusPublished - Jun 15 2015

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formic acid
Ions
Decomposition
Kinetics
Chlorides
Hydrolysis
Nuclear magnetic resonance
Wavelength
glycine chloramine
hydroxide ion
glyoxylic acid
N-formylglycine
oxalylglycine
Proton Magnetic Resonance Spectroscopy
Carbon-13 Magnetic Resonance Spectroscopy

ASJC Scopus subject areas

  • Toxicology

Cite this

Decomposition of N-Chloroglycine in Alkaline Aqueous Solution : Kinetics and Mechanism. / Szabó, Mária; Baranyai, Z.; Somsák, L.; Fábián, I.

In: Chemical Research in Toxicology, Vol. 28, No. 6, 15.06.2015, p. 1282-1291.

Research output: Contribution to journalArticle

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