Iodine-azide reaction

The disulfide has a special interest as the catalyst in the carbon disulfide-catalyzed iodine-azide reaction. No perceptible nitrogen evolution will take place in a solution containing iodine and azide ions without the presence of a catalyst. Thiosulfates, sulfides, and many other sulfur compounds act as catalysts. In 1922 Browne et found that carbon disulfide is a powerful catalyst in this... 

N. Hofman-Bang, The Iodine-Azide Reaction. C. A. Reitzels Forlag, Copenhagen, 1952. 

According to Hofman-Bang carbon sulfide selenide, CSSe, catalyzes the iodine-azide reaction but is at the same time decomposed with the formation of selenium. Experiments, in both this laboratory and that of Hofman-Bang have shown that carbon diselenide reacts with sodium azide (in aqueous or aqueous-alcoholic solution) with immediate precipitation of red selenium even at — 20° C. //a selena-triazole is formed in this reaction it must be extremely unstable. 

The detection depends on the iodine azide reaction that normally takes place very slowly and during the course of which sodium azide reacts with iodine to form sodium iodide with the production of nitrogen ... 

However, the starch solution should not be omitted completely since the color difference between the chromatogram zones, in which the iodine is reduced to colorless iodide according to the iodine azide reaction mentioned above, and the background colored brown by unreacted iodine is considerably less than the difference in color between the deep blue background provided by the starch-iodine clathrate complex and the pale chromatogram zones. 

Ridomil, with which the treatment with starch solution was not carried out, is said to yield brown chromatogram zones on a pale yellow background [14]. Hence, it may be assumed that this detection is based not on the iodine azide reaction but on the physical adsorption and enrichment of iodine in the lipophilic chromatogram zones (cf. Iodine Reagents ). 

Insulin derivatives lb 401 lodate anions la 188,190 lb 307 Iodine staining lb 278 Iodine-azide reaction lb 85,301-304 Iodide anions la 190 lb 76,77,128,129 Iodide vapor la 46,64,78 lodination la 66... 

Puacz et al. (1995) developed a catalytic method, based on the iodine-azide reaction, for the determination of hydrogen sulfide in human whole blood. The method involves the generation of hydrogen sulfide in an evolution-absorption apparatus. In addition, the method allows for the determination of sulfide in blood without interference from other sulfur compounds in blood. A detection limit of 4 g/dm3 and a percent recovery of 98-102% were achieved. Although the accuracy and precision of the catalytic method are comparable to those of the ion-selective electrode method, the catalytic method is simpler, faster, and would be advantageous in serial analysis. 

Special test Catalysis of iodine-azide reaction solution of sodium azide (NaN3) and iodine reacts with a trace of a sulfide to evolve nitrogen thiosulfates and thiocyanates act similarly and therefore must be absent... 

Catalysis of iodine-azide reaction test Solutions of sodium azide, NaN3, and of iodine (as I3) do not react, but on the addition of a trace of a sulphide, which acts as a catalyst, there is an immediate evolution of nitrogen ... 

Catalysis of iodine-azide reaction test Traces of thiocyanates act as powerful catalysts in the otherwise extremely slow reaction between triiodide (iodine) and sodium azide ... 

Catalysis of the iodine-azide reaction by thiosulphate leads to very rapid reaction for which no kinetic data are available. Raschig proposed the intermediate 8203 , and this has been considered more fully . Weiss suggested that all these reactions involve iodine atoms. In the absence of kinetic measurements discussion is premature. The corresponding tetrathionate system has received kinetic study. Dodd and Griffith found evidence for some direct decomposition of the thionate by iodide and iodine in acetate buffers, and they propose the reactions... 

Others authors propose alternative ways to conduct or discuss an experiment that is already commonly used in the teaching of chemical kinetics. For example the presentation of a videotaped clock (iodine-azide) reaction which is suitable for videotaping and which has an easily determined mechanism (Haight Jones, 1987) the determination of a reaction mechanism of the blue bottle reaction (Engerer Cook, 1999). Others may be used to discuss thermodynamics and kinetics simultaneously, e.g., from the study of the surface of nanomaterials (such as a gold colloid monolayer) (Keating, Musick, Keefe Natan, 1999), and from the study of a chemical equihbrium in solution (Leenson, 1986). 

Haight, G.P., Jones, L.L. (1987). Kinetics and mechanism of the iodine-azide reaction. Journal of Chemical Education, 64, 271-273. 

Kurzawa, J. 1987. The iodine-azide reaction induced by mercaptopyrimidines and its application in chemical analysis. Chem. Anal. 32 (6) 875-90 cited in Chem. Abstr. Ca 111(20) 186650a. 

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