ChemInform Abstract: KINETICS AND MECHANISM OF THE EPOXIDATION OF FUMARIC ACID WITH AQUEOUS HYDROGEN PEROXIDE CATALYZED BY SODIUM TUNGSTATE OR SODIUM MOLYBDATE

1975 ◽  
Vol 6 (47) ◽  
pp. no-no
Author(s):  
M. AIJAZ BEG ◽  
IFTIKHAR AHMAD
Keyword(s):  
Hydrogen Peroxide ◽  
Fumaric Acid ◽  
Sodium Tungstate ◽  
Sodium Molybdate ◽  
Kinetics And Mechanism ◽  
Aqueous Hydrogen Peroxide

Preparation of 4-Hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl A Reinvestigation of Methods Using Hydrogen Peroxide in the Presence of Catalysts

1976 ◽  
Vol 31 (10) ◽  
pp. 1376-1378 ◽  
Author(s):  
G. Sosnovsky ◽  
M. Konieczny
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphotungstic Acid ◽  
Sodium Tungstate ◽  
Spin Labeling ◽  
Quantitative Yield ◽  
Hydrogen Peroxide Solution ◽  
Aqueous Hydrogen Peroxide ◽  
Molar Excess

The preparation of the key intermediate for spin labeling, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (2), was reinvestigated using sodium tungstate or phosphotungstic acid with or without either Trilon or Triton B. A two-fold and a 3.5-fold molar excess of a 30% aqueous hydrogen peroxide solution was used. The oxidation of 4-hydroxy-2,2,6,6-tetramethylpiperidine (1) with a two-fold molar excess of a 30% aqueous hydrogen peroxide solution in the presence of sodium tungstate alone, under vigorous stirring for two hours, is the superior method (A) for the preparation of 2 in virtually quantitative yield.

Kinetics of the oxidation of dimethyl sulfoxide with aqueous hydrogen peroxide catalyzed by sodium tungstate

1981 ◽  
Vol 59 (4) ◽  
pp. 718-722 ◽  
Author(s):  
Yoshiro Ogata ◽  
Kazushige Tanaka
Keyword(s):  
Hydrogen Peroxide ◽  
Dimethyl Sulfoxide ◽  
Sodium Tungstate ◽  
Catalytic Amount ◽  
Active Oxygen ◽  
Probable Mechanism ◽  
Polarographic Study ◽  
Aqueous Hydrogen Peroxide ◽  
First Order ◽  
Kinetics Of

The oxidation of dimethyl sulfoxide (DMSO) by hydrogen peroxide in the presence of a catalytic amount of sodium tungstate (Na2WO4) has been studied kinetically by means of iodometry of hydrogen peroxide. The reaction is first-order with respect to the substrate and the catalyst, but independent of the concentration of hydrogen peroxide which is present in excess of the catalyst. The polarographic study implies that in solutions two main kinds of peroxytungstic acids (H2WO5 and H2WO8) are formed which contain active oxygen in ratios (active oxygen):(Na2WO4) of 1:1 and 4:1, respectively. The effect of acidity on the oxidation rate and a probable mechanism involving a rate-determining attack of peroxytungstic acids are discussed.

Preparation and Application of P-Mo-W Heteropoly Acid Catalyst

2013 ◽  
Vol 838-841 ◽  
pp. 2374-2378
Author(s):  
Jun Deng ◽  
Xue Jun Zhu ◽  
Shuai Xie
Keyword(s):  
Hydrogen Peroxide ◽  
Mass Fraction ◽  
Heteropoly Acid ◽  
Sodium Tungstate ◽  
Raw Materials ◽  
Glyoxylic Acid ◽  
Sodium Molybdate ◽  
Acid Catalyst ◽  
Molar Ratio ◽  
The Impact

the phosphorus-molybdenum-tungsten heteropoly acid catalyst is prepared from such raw materials as phosphoric acid, sodium molybdate, sodium tungstate and characterized by infrared spectrum. Glyoxylic acid is prepared by catalytic oxidation of glyoxal in the presence of the self-prepared heteropoly acid catalyst and oxidizing agent hydrogen peroxide. The impact of catalytic reaction temperature, added catalyst, and use level of the hydrogen peroxide on the reaction for synthesizing the glyoxylic acid is investigated. The results show under such conditions as 4°C temperature, 0.15g catalyst, and 1.2:1 molar ratio of the hydrogen peroxide to the glyoxal, the phosphorus-molybdenum-tungsten heteropoly acid catalyst has higher catalytic activity and the mass fraction of the glyoxylic acid is 30%.

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