Abstract
Numerous researchers have been studying the liquid-phase autoxidation by molecular oxygen of compounds containing a mercapto group. It has been stated that, in the course of the reaction, sulphide is formed, but the exact mechanism of this process has not been determined. The oxidation of mercaptoacetic acid, at 50{sup o}C and at a pH of 8, was investigated both in the presence of Complexon IV and in the presence of iron-ions. Na{sub 2}S, labelled with S{sup 35}, was introduced into the system and it was determined that this sulphide considerably increases the rate of the oxygen uptake both in the processes catalysed by trivalent iron and free of iron-ions. In the course of the reaction the concentration of the sulphide, its specific activity and its total activity were measured. In using these data and on the basis of the kinetic isotopic method developed by Neiman and co-workers, it was possible to calculate the rate of sulphide formation and its further oxidation. In comparing these data with other kinetic data, it is shown that the oxidation of mercaptoacetic acid in the liquid phase is a branching chain reaction; one of its principal chains being the formation of Na{sub 2}S and its
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Citation Formats
Gal, D, and Guczi, L.
Isotopic data to study the mechanism of the oxidation of mercaptoacetic acid; Donnees isotopiques pour l'etude du mecanisme d'oxydation de l'acide mercaptoacetique; Izotopnyj metod issledovaniya mekhanizma okisleniya merkapgouksusnoj kisloty; Estudio del mecanismo de oxidacion del acido mercaptoacetico por medio de datos obtenidos con radioisotopos.
IAEA: N. p.,
1962.
Web.
Gal, D, & Guczi, L.
Isotopic data to study the mechanism of the oxidation of mercaptoacetic acid; Donnees isotopiques pour l'etude du mecanisme d'oxydation de l'acide mercaptoacetique; Izotopnyj metod issledovaniya mekhanizma okisleniya merkapgouksusnoj kisloty; Estudio del mecanismo de oxidacion del acido mercaptoacetico por medio de datos obtenidos con radioisotopos.
IAEA.
Gal, D, and Guczi, L.
1962.
"Isotopic data to study the mechanism of the oxidation of mercaptoacetic acid; Donnees isotopiques pour l'etude du mecanisme d'oxydation de l'acide mercaptoacetique; Izotopnyj metod issledovaniya mekhanizma okisleniya merkapgouksusnoj kisloty; Estudio del mecanismo de oxidacion del acido mercaptoacetico por medio de datos obtenidos con radioisotopos."
IAEA.
@misc{etde_22025725,
title = {Isotopic data to study the mechanism of the oxidation of mercaptoacetic acid; Donnees isotopiques pour l'etude du mecanisme d'oxydation de l'acide mercaptoacetique; Izotopnyj metod issledovaniya mekhanizma okisleniya merkapgouksusnoj kisloty; Estudio del mecanismo de oxidacion del acido mercaptoacetico por medio de datos obtenidos con radioisotopos}
author = {Gal, D, and Guczi, L}
abstractNote = {Numerous researchers have been studying the liquid-phase autoxidation by molecular oxygen of compounds containing a mercapto group. It has been stated that, in the course of the reaction, sulphide is formed, but the exact mechanism of this process has not been determined. The oxidation of mercaptoacetic acid, at 50{sup o}C and at a pH of 8, was investigated both in the presence of Complexon IV and in the presence of iron-ions. Na{sub 2}S, labelled with S{sup 35}, was introduced into the system and it was determined that this sulphide considerably increases the rate of the oxygen uptake both in the processes catalysed by trivalent iron and free of iron-ions. In the course of the reaction the concentration of the sulphide, its specific activity and its total activity were measured. In using these data and on the basis of the kinetic isotopic method developed by Neiman and co-workers, it was possible to calculate the rate of sulphide formation and its further oxidation. In comparing these data with other kinetic data, it is shown that the oxidation of mercaptoacetic acid in the liquid phase is a branching chain reaction; one of its principal chains being the formation of Na{sub 2}S and its further oxidation. Moreover, it was determined that sulphate is formed in the course of the reaction only through the inorganic sulphide. Iron-ions catalyse the formation of organic disulphide and therefore also have influence on the sulphide formation. (author) [French] De nombreux chercheurs ont etudie l'autoxydation des composes contenant un groupe mercaptan par l'oxygene moleculaire en phase liquide. Ils ont trouve qu'il y avait formation de sulfure au cours de la reaction, mais le mecanisme exact de ce processus n'a pas ete determine. L'oxydation de l'acide mercaptoacetique a 50{sup o}C et pour un pH de 8 a ete etudiee en presence de complexone IV et egalement; en presence de fer. Du Na{sub 2}S marque au {sup 35}S a ete introduit dans le systeme et on a constate que le Na{sub 2}S augmentait considerablement le taux d'absorption d'oxygene, tant dans le processus de catalysation par le fer qu'en l'absence de fer. Au cours de la reaction, on a mesure la concentration du sulfure, son activite specifique et son activite totale. En. partant de ces donnees, et en utilisant la methode d'etude cinetique au moyen d'isotopes, mise au point par Neiman et ses collaborateurs, on a pu calculer le taux de formation de sulfure et le taux de son oxydation ulterieure. La comparison de ces donnees avec d'autres donnees cinetiques revele que l'oxydation de l'acide mercaptoacetique en phase liquide est une reaction en chaine ramifiee, l'un des principaux elements de cette chaine etant la formation de Na{sub 2}S et son oxydation ulterieure. On a constate en outre qu'il se forme du sulfate, lors de la reaction, mais seulement a partir du sulfure mineral. Le fer catalyse la formation de disulfure organique et, de ce fait, influe aussi sur la formation de sulfure. (author) [Spanish] Numerosos investigadores han estudiado la autooxidacion en fase liquida, por oxigeno molecular, de compuestos que contienen un grupo mercaptano; si bien han llegado a la conclusion de que se forman sulfuros en el curso de la reaccion, el mecanismo exacto del proceso no se conoce. Los autores estudiaron la autooxidacion del acido mercaptoacetico a 50{sup o} C y pH 8 en presencia de complexon IV y de hierro. Anadieron al sistema Na{sub 2}S marcado con {sup 35}S y comprobaron que este compuesto aumenta notablemente la velocidad de absorcion de oxigeno tanto en las reacciones catalizadas por hierro como en las que transcurren en ausencia de iones de este metal. En el curso de la reaccion, los autores midieron la concentracion del sulfuro, su actividad especifica y su actividad total. Gracias a estos datos y empleando el metodo isotopico cinetico establecido por Neiman y colaboradores, pudieron calcular la velocidad de formacion del sulfuro y la velocidad de su oxidacion subsiguiente. Por comparacion de esos resultados con otros datos cineticos, se puede demostrar que la autooxidacion del acido mercaptoacetico en fase liquida constituye una reaccion en cadena ramificada, una de cuyas ramas principales es la formacion de Na{sub 2}S y su oxidacion subsiguiente. Los autores tambien comprobaron que el sulfato que aparece durante la reaccion, procede exclusivamente del sulfuro inorganico. El hierro cataliza la formacion de disulfuro organico y, por lo tanto, ejerce tambien influencia sobre la formacion del sulfuro. (author) [Russian] Mnogie issledovateli izuchali protsessy samookisleniya slozhnykh veshchestv, soderzhashchikh merkaptonovuyu gruppu, s pomoshch'yu molekulyarnogo kisloroda v zhidkoj faze. Ukazyvalos', chto vo vremya reaktsii obrazuetsya sul'fid, no do sikh por ne udavalos' opredelit' tochnogo mekhanizma ehtogo protsessa. Bylo provedeno issledovanie okisleniya merkaptouksusnoj kisloty pri 50{sup o} i pri pH = 8 kak v prisutstvii kompleksona IV, tak i v prisutstvii zheleza. V sistemu byl vveden Na{sub 2}S, mechennyj S{sup 35}, i bylo ustanovleno, chto Na{sub 2}S znachitel'no uvelichivaet skorost' zakhvata kisloroda kak pri protsesse katalizirovannym zhelezom, tak i v protsesse, svobodnom ot ionov zheleza. Vo vremya reaktsii byli izmereny kontsentratsiya sul'fida, ego udel'naya aktivnost' i obshchaya aktivnost'. Na osnovanii ehtikh dannykh i blagodarya vyrabotannomu Nejmanom i ego sotrudnikami kineticheskomu metodu izotopov, predstavilos' vozmozhnym podschitat' temp obrazovaniya sul'fida i ego dal'nejshego okisleniya. Sopostavlenie ehtikh dannykh s drugimi kineticheskimi dannymi pokazalo, chto okislenie merkaptouksusnoj kisloty v zhidkoj faze yavlyaetsya tsepnoj reaktsiej odna iz glavnykh tsepej v ehtoj reaktsii obrazuetsya posredstvom obrazovaniya Na{sub 2}S i ego dal'nejshego okisleniya. Krome togo, bylo ustanovleno, chto vo vremya reaktsii obrazuetsya sul'fat, no tol'ko cherez posredstvo neorganicheskogo sul'fida. Zhelezo katalizirovalo obrazovanie organicheskogo disul'fida i poehtomu ono takzhe okazyvaet vliyanie na obrazovanie sul'fida. (author)}
place = {IAEA}
year = {1962}
month = {Mar}
}
title = {Isotopic data to study the mechanism of the oxidation of mercaptoacetic acid; Donnees isotopiques pour l'etude du mecanisme d'oxydation de l'acide mercaptoacetique; Izotopnyj metod issledovaniya mekhanizma okisleniya merkapgouksusnoj kisloty; Estudio del mecanismo de oxidacion del acido mercaptoacetico por medio de datos obtenidos con radioisotopos}
author = {Gal, D, and Guczi, L}
abstractNote = {Numerous researchers have been studying the liquid-phase autoxidation by molecular oxygen of compounds containing a mercapto group. It has been stated that, in the course of the reaction, sulphide is formed, but the exact mechanism of this process has not been determined. The oxidation of mercaptoacetic acid, at 50{sup o}C and at a pH of 8, was investigated both in the presence of Complexon IV and in the presence of iron-ions. Na{sub 2}S, labelled with S{sup 35}, was introduced into the system and it was determined that this sulphide considerably increases the rate of the oxygen uptake both in the processes catalysed by trivalent iron and free of iron-ions. In the course of the reaction the concentration of the sulphide, its specific activity and its total activity were measured. In using these data and on the basis of the kinetic isotopic method developed by Neiman and co-workers, it was possible to calculate the rate of sulphide formation and its further oxidation. In comparing these data with other kinetic data, it is shown that the oxidation of mercaptoacetic acid in the liquid phase is a branching chain reaction; one of its principal chains being the formation of Na{sub 2}S and its further oxidation. Moreover, it was determined that sulphate is formed in the course of the reaction only through the inorganic sulphide. Iron-ions catalyse the formation of organic disulphide and therefore also have influence on the sulphide formation. (author) [French] De nombreux chercheurs ont etudie l'autoxydation des composes contenant un groupe mercaptan par l'oxygene moleculaire en phase liquide. Ils ont trouve qu'il y avait formation de sulfure au cours de la reaction, mais le mecanisme exact de ce processus n'a pas ete determine. L'oxydation de l'acide mercaptoacetique a 50{sup o}C et pour un pH de 8 a ete etudiee en presence de complexone IV et egalement; en presence de fer. Du Na{sub 2}S marque au {sup 35}S a ete introduit dans le systeme et on a constate que le Na{sub 2}S augmentait considerablement le taux d'absorption d'oxygene, tant dans le processus de catalysation par le fer qu'en l'absence de fer. Au cours de la reaction, on a mesure la concentration du sulfure, son activite specifique et son activite totale. En. partant de ces donnees, et en utilisant la methode d'etude cinetique au moyen d'isotopes, mise au point par Neiman et ses collaborateurs, on a pu calculer le taux de formation de sulfure et le taux de son oxydation ulterieure. La comparison de ces donnees avec d'autres donnees cinetiques revele que l'oxydation de l'acide mercaptoacetique en phase liquide est une reaction en chaine ramifiee, l'un des principaux elements de cette chaine etant la formation de Na{sub 2}S et son oxydation ulterieure. On a constate en outre qu'il se forme du sulfate, lors de la reaction, mais seulement a partir du sulfure mineral. Le fer catalyse la formation de disulfure organique et, de ce fait, influe aussi sur la formation de sulfure. (author) [Spanish] Numerosos investigadores han estudiado la autooxidacion en fase liquida, por oxigeno molecular, de compuestos que contienen un grupo mercaptano; si bien han llegado a la conclusion de que se forman sulfuros en el curso de la reaccion, el mecanismo exacto del proceso no se conoce. Los autores estudiaron la autooxidacion del acido mercaptoacetico a 50{sup o} C y pH 8 en presencia de complexon IV y de hierro. Anadieron al sistema Na{sub 2}S marcado con {sup 35}S y comprobaron que este compuesto aumenta notablemente la velocidad de absorcion de oxigeno tanto en las reacciones catalizadas por hierro como en las que transcurren en ausencia de iones de este metal. En el curso de la reaccion, los autores midieron la concentracion del sulfuro, su actividad especifica y su actividad total. Gracias a estos datos y empleando el metodo isotopico cinetico establecido por Neiman y colaboradores, pudieron calcular la velocidad de formacion del sulfuro y la velocidad de su oxidacion subsiguiente. Por comparacion de esos resultados con otros datos cineticos, se puede demostrar que la autooxidacion del acido mercaptoacetico en fase liquida constituye una reaccion en cadena ramificada, una de cuyas ramas principales es la formacion de Na{sub 2}S y su oxidacion subsiguiente. Los autores tambien comprobaron que el sulfato que aparece durante la reaccion, procede exclusivamente del sulfuro inorganico. El hierro cataliza la formacion de disulfuro organico y, por lo tanto, ejerce tambien influencia sobre la formacion del sulfuro. (author) [Russian] Mnogie issledovateli izuchali protsessy samookisleniya slozhnykh veshchestv, soderzhashchikh merkaptonovuyu gruppu, s pomoshch'yu molekulyarnogo kisloroda v zhidkoj faze. Ukazyvalos', chto vo vremya reaktsii obrazuetsya sul'fid, no do sikh por ne udavalos' opredelit' tochnogo mekhanizma ehtogo protsessa. Bylo provedeno issledovanie okisleniya merkaptouksusnoj kisloty pri 50{sup o} i pri pH = 8 kak v prisutstvii kompleksona IV, tak i v prisutstvii zheleza. V sistemu byl vveden Na{sub 2}S, mechennyj S{sup 35}, i bylo ustanovleno, chto Na{sub 2}S znachitel'no uvelichivaet skorost' zakhvata kisloroda kak pri protsesse katalizirovannym zhelezom, tak i v protsesse, svobodnom ot ionov zheleza. Vo vremya reaktsii byli izmereny kontsentratsiya sul'fida, ego udel'naya aktivnost' i obshchaya aktivnost'. Na osnovanii ehtikh dannykh i blagodarya vyrabotannomu Nejmanom i ego sotrudnikami kineticheskomu metodu izotopov, predstavilos' vozmozhnym podschitat' temp obrazovaniya sul'fida i ego dal'nejshego okisleniya. Sopostavlenie ehtikh dannykh s drugimi kineticheskimi dannymi pokazalo, chto okislenie merkaptouksusnoj kisloty v zhidkoj faze yavlyaetsya tsepnoj reaktsiej odna iz glavnykh tsepej v ehtoj reaktsii obrazuetsya posredstvom obrazovaniya Na{sub 2}S i ego dal'nejshego okisleniya. Krome togo, bylo ustanovleno, chto vo vremya reaktsii obrazuetsya sul'fat, no tol'ko cherez posredstvo neorganicheskogo sul'fida. Zhelezo katalizirovalo obrazovanie organicheskogo disul'fida i poehtomu ono takzhe okazyvaet vliyanie na obrazovanie sul'fida. (author)}
place = {IAEA}
year = {1962}
month = {Mar}
}