The mechanism of oxidation of 3-mercaptopropionic acid

The mechanism of the oxidation of 3-mercaptopropionic acid (3-MPA) by hydrogen peroxide was studied in the acidic pH range. The nucleophilic attack by sulphur on the peroxide bond controls the rate. Extrapolation of the pH dependency suggests that the rate of attack by the deprotonated dianion is hi...

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Publicado:	1997
Materias:	3-mercaptopropionic acid Autooxidation Electrochemistry Kinetics Catalysis Charge transfer Cyclic voltammetry Electrons Hydrogen peroxide Iron compounds Organic acids pH Polarographic analysis Reaction kinetics Deprotonated dianion Mercaptopropionic acid Nucleophilic attack Second electron transfer step Oxidation
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00084042_v75_n1_p9_Forlano http://hdl.handle.net/20.500.12110/paper_00084042_v75_n1_p9_Forlano
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00084042_v75_n1_p9_Forlano
record_format	dspace
spelling	paper:paper_00084042_v75_n1_p9_Forlano2023-06-08T14:31:57Z The mechanism of oxidation of 3-mercaptopropionic acid 3-mercaptopropionic acid Autooxidation Electrochemistry Kinetics Catalysis Charge transfer Cyclic voltammetry Electrochemistry Electrons Hydrogen peroxide Iron compounds Organic acids pH Polarographic analysis Reaction kinetics Autooxidation Deprotonated dianion Mercaptopropionic acid Nucleophilic attack Second electron transfer step Oxidation The mechanism of the oxidation of 3-mercaptopropionic acid (3-MPA) by hydrogen peroxide was studied in the acidic pH range. The nucleophilic attack by sulphur on the peroxide bond controls the rate. Extrapolation of the pH dependency suggests that the rate of attack by the deprotonated dianion is highest. Traces of Fe(III), at levels below 10-7 mol dm-3, do not catalyze efficiently the process through one-electron mechanisms; at higher concentrations, or on the surface of iron(III) oxides, this type of catalysis becomes important. The electrochemical oxidation of 3-MPA was also studied, using differential pulse polarography and cyclic voltammetry techniques. The mechanism is of the EC2E type, the second electron transfer step corresponding to the oxidation of the disulphide RS-SR. The rate constant for the dimerization of the RS. radicals was 1.8 × 103 mol-1 dm3 s-1; the slowness of this step agrees with the mechanisms observed in the course of one-electron oxidations by metal ions. 1997 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00084042_v75_n1_p9_Forlano http://hdl.handle.net/20.500.12110/paper_00084042_v75_n1_p9_Forlano
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	3-mercaptopropionic acid Autooxidation Electrochemistry Kinetics Catalysis Charge transfer Cyclic voltammetry Electrochemistry Electrons Hydrogen peroxide Iron compounds Organic acids pH Polarographic analysis Reaction kinetics Autooxidation Deprotonated dianion Mercaptopropionic acid Nucleophilic attack Second electron transfer step Oxidation
spellingShingle	3-mercaptopropionic acid Autooxidation Electrochemistry Kinetics Catalysis Charge transfer Cyclic voltammetry Electrochemistry Electrons Hydrogen peroxide Iron compounds Organic acids pH Polarographic analysis Reaction kinetics Autooxidation Deprotonated dianion Mercaptopropionic acid Nucleophilic attack Second electron transfer step Oxidation The mechanism of oxidation of 3-mercaptopropionic acid
topic_facet	3-mercaptopropionic acid Autooxidation Electrochemistry Kinetics Catalysis Charge transfer Cyclic voltammetry Electrochemistry Electrons Hydrogen peroxide Iron compounds Organic acids pH Polarographic analysis Reaction kinetics Autooxidation Deprotonated dianion Mercaptopropionic acid Nucleophilic attack Second electron transfer step Oxidation
description	The mechanism of the oxidation of 3-mercaptopropionic acid (3-MPA) by hydrogen peroxide was studied in the acidic pH range. The nucleophilic attack by sulphur on the peroxide bond controls the rate. Extrapolation of the pH dependency suggests that the rate of attack by the deprotonated dianion is highest. Traces of Fe(III), at levels below 10-7 mol dm-3, do not catalyze efficiently the process through one-electron mechanisms; at higher concentrations, or on the surface of iron(III) oxides, this type of catalysis becomes important. The electrochemical oxidation of 3-MPA was also studied, using differential pulse polarography and cyclic voltammetry techniques. The mechanism is of the EC2E type, the second electron transfer step corresponding to the oxidation of the disulphide RS-SR. The rate constant for the dimerization of the RS. radicals was 1.8 × 103 mol-1 dm3 s-1; the slowness of this step agrees with the mechanisms observed in the course of one-electron oxidations by metal ions.
title	The mechanism of oxidation of 3-mercaptopropionic acid
title_short	The mechanism of oxidation of 3-mercaptopropionic acid
title_full	The mechanism of oxidation of 3-mercaptopropionic acid
title_fullStr	The mechanism of oxidation of 3-mercaptopropionic acid
title_full_unstemmed	The mechanism of oxidation of 3-mercaptopropionic acid
title_sort	mechanism of oxidation of 3-mercaptopropionic acid
publishDate	1997
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00084042_v75_n1_p9_Forlano http://hdl.handle.net/20.500.12110/paper_00084042_v75_n1_p9_Forlano
_version_	1768541684277182464

The mechanism of oxidation of 3-mercaptopropionic acid

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