Kinetics and mechanism of the decomposition of N-chloroalanine in aqueous solution

Stanbro, W.D.; Smith, William Thomas Lingwood

doi:10.1021/es60152a002

Cited by 63 publications

(45 citation statements)

References 9 publications

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“…The N-X-Valine is formed in less than one second by mixing the amino acid and the hypohalite solutions (both with a pH value of approximately 9.5). The reaction was always followed at 255 nm, the wavelength at which N-C1-Valine presents the maximum of absorption, this value coincides with that of most of other N-C1-amino acids [7,8]. The absorption spectrum of the N-C1-Valine does not vary with the pH value of the solution (between 4-14).…”

Section: Methodsmentioning

confidence: 65%

General base catalysis in the decomposition of N‐Cl‐Valine in aqueous solution

Abia

Armesto

Canle

et al. 1994

Int J of Chemical Kinetics

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This article analyzes the kinetics of the decomposition of N-C1-Valine in aqueous solution, which is formed rapidly by chlorination of Valine with sodium hypochlorite. A general-base catalyzed process not yet described is reported. The experimental evidence shows two competitive decomposition paths: an unimolecular concerted fragmentation process (k = (1.8 ? 0.1) .s-l at 298 K) and the other one is an E2 elimination process whose importance increases with pH and depends on the nature and the concentration of the bases present in the medium.

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Section: Methodsmentioning

confidence: 65%

General base catalysis in the decomposition of N‐Cl‐Valine in aqueous solution

Abia

Armesto

Canle

et al. 1994

Int J of Chemical Kinetics

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“…The following main points emerged. NCP and NCDEA are considerably longer lived compounds (3.3 days and 2.2 days, respectively, at 25°C at pH 7.0) than the N-chloroamino acid, N-chloroalanine (55 min), calculated from the data of Stanbro and Smith (19). The half-lives of all three compounds do not change from pH 3.5 to pH 9, but increase dramatically below pH 3.0. Early in our study we found when we followed the NCP concentration by continuously monitoring its absorbance maximum at 262 nm that we photodecomposed it in the sample chamber of the spectrophotometer.…”

Section: Stability Of Organic N-chloraminesmentioning

confidence: 82%

Organic N-chloramines: chemistry and toxicology.

Scully¹,

Bempong²

1982

Environ Health Perspect

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The stability of aqueous solutions of organic N-chloramines, suspected of contaminating chlorinated water, has been studied. Two factors influence the decomposition of solutions of N-chloropiperidine and N-chlorodiethylamine: a spontaneous decomposition and photodecomposition. Since solutions of these compounds are relatively long-lived, a need for an analytical method for their identification is discussed. A new method is described which involves reaction of organic N-chloramines with arenesulfinic acid salts. The method gives high yields of stable arenesulfonamides. Several toxicological studies ofN-chloropiperidine are described. The compound is mutagenic by Ames assay in Salmonella typhimurium strain TA 100 and does not require metabolic activation as indicated in a total body fluids analysis using C57BL/J6 mice. N-Chloropiperidine was subjected to a modified in vitro cell transformation assay using diploid fibroblast cells from Syrian hamster fetuses. A maximum number of foci of 4 per dish was observed at a seeding of 5 x 103 cells/60 mm dish. Under similar conditions, MNNG-induced foci ranged from 4 to 7 per dish.

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“…41 Systematic studies on the kinetics and mechanism of the decomposition of N-chlorinated amino acids postulate the formation of imines which undergo further reactions. 20,21,23,[44][45][46][47][48][49][50] Some of these investigations suggests that decarboxylation and the loss of chloride ion occurs via a concerted Grob fragmentation mechanism. [51][52][53] Earlier results on the decomposition kinetics are somewhat controversial.…”

Section: Introductionmentioning

confidence: 99%

Decomposition of N-Chloroglycine in Alkaline Aqueous Solution: Kinetics and Mechanism

Szabó

Baranyai

Somsák

et al. 2015

Chem. Res. Toxicol.

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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 (1)H and (13)C 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.

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Kinetics and mechanism of the decomposition of N-chloroalanine in aqueous solution

Cited by 63 publications

References 9 publications

General base catalysis in the decomposition of N‐Cl‐Valine in aqueous solution

General base catalysis in the decomposition of N‐Cl‐Valine in aqueous solution

Organic N-chloramines: chemistry and toxicology.

Decomposition of N-Chloroglycine in Alkaline Aqueous Solution: Kinetics and Mechanism

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