Potassium hypoiodite

The reactions involved are similar in both cases, and closely parallel to those which give rise to chloroform. The sodium hypochlorite probably first oxidises the potassium iodide to potassium hypoiodite, which then oxidises the ethanol to acetaldehyde and then iodinates the latter to tri-iodo ... 

G. F. Schonbein, as previously indicated, found that when iodine water is mixed with potassium hydroxide, the analogy of the product with soln. of the hypo-bromites and hypochlorites shows that potassium hypoiodite is in all probability formed by a reversible reaction, 2KOH +I2 KI +KOI+H20, and that, when in equilibrium, the addition of potassium iodide will reverse the reaction, forming free iodine and potassium hydroxide. Hence, (i) the amount of potassium hydroxide required to complete the reaction must be greater than is indicated by the equation, as was found to be the case by R. L. Taylor and (ii) the failure of many to obtain evidence of bleaching soln. of hypoiodite when soln. of iodine in potassium iodide are employed. If a large excess of potassium iodide is present, this will prevent... 

The fourth student in this group, Stanford Moore, began his doctoral thesis research with Link in 1935. His work involved the development of a new, and still useful, procedure for oxidizing aldoses to the aldonic acids by potassium hypoiodite in methanol solution the resulting aldonic acids were then converted into nicely crystalline benzimidazole derivatives that proved more suitable for the characterization of carbohydrates than the classical osazones. This method, developed by Moore and Link (1940), was extended to the characterization of hexuronic acids, as their bis(benzimidazole)s, after oxidation to the glycaric acid (R. Lohmar, Dimler, Moore, and Link, 1942), of lactic acid (Moore, Dimler, and Link, 1941 Dimler and Link, 1942), and of ribose, fucose, and digitoxose (Dimler and Link, 1943). During these... 

Potassium hypoiodite, KOI.—The hypoiodite has not been isolated, but is formed in aqueous solution by the interaction of iodine and a dilute solution of potassium hydroxide ... 

This method involves the oxidation of aldoses to aldonic acids by potassium hypoiodite in methanol and the condensation of the isolated potassium salt of the aldonic acid in hot acid with o-phenylenediamine (M3). The specific aldobenzimidazole can be identified by the solubility in water, optical rotation in acid, and melting point. This method is not as simple as chromatography. It requires dehydration of the sample and a relatively high concentration of the sugars to be identified. 

Crystalline nitrogen triiodide can be prepared by reaction of aqueous iodine monochloride (ICl) alkalized by potassium hydroxide with aqueous ammonia. On cooling, nitrogen triiodide forms as blackish-brown shiny needles, up to 2 mm long [54, 66], Nitrogen triiodide is also formed by addition of ammonia to alkaline solutions of potassium hypoiodite (KIO) [54]. Other iodizing agents such as iodine monobromides or dibromoiodides can be used as well [46]. 

The potassium and calcium salts of D-[U- C]-gluconic acid have been prepared by oxidation of labelled glucose with potassium hypoiodite and with bromine in the presence of calcium carbonate, respectively. ... 

Acetaldehyde reacts with phosphoms pentachloride to produce 1,1-dichloroethane [75-34-3] and with hypochlorite and hypoiodite to yield chloroform [67-66-3] and iodoform [75-47-8], respectively. Phosgene [75-44-5] is produced by the reaction of carbon tetrachloride with acetaldehyde in the presence of anhydrous aluminum chloride (75). Chloroform reacts with acetaldehyde in the presence of potassium hydroxide and sodium amide to form l,l,l-trichloro-2-propanol [7789-89-1] (76). 

All forms of iodine including the elemental iodine, hypoiodous acid (HOI), hypoiodite anion (OI ), free iodide anion (I-), and triiodide anion (I3 ) in water also may be measured by the Leuco crystal violet method. The sample is treated with potassium peroxymonosulfate to oxidize all iodide species in the sample. It then is treated with leukocrystal violet reagent for color development. Interference from free chlorine may be eliminated by addition of an ammonium salt. 

Oxidation of acetyl- and acetylnitro-substituted thienothiophenes 1 and 2 with ferricyanide or hypoiodite to the corresponding acids was used primarily to confirm the site of electrophilic substitution at position 2 in the thienothiophenes. " Permanganate degrades the thieno[3,2-A]-thiophene (2) ring system, while potassium hypobromite produced bromo derivatives of thieno[2,3-6]thiophene-2-carboxylic acid. ... 

C. F. Schonbein also prepared ammonium hypobromite by a process analogous to that employed for the hypochlorite, and obtained a liquid with similar oxidizing properties. The liquid is assumed to contain a mixture of ammonium hypobromite and bromide. C. F. Schonbein likewise inferred the transient formation of ammonium hypoiodite when iodine water and aqueous ammonia are mixed, whereby the liquid is decolorized. The soln. gave a deep blue coloration with starch paste and potassium iodide, etc., and behaved like analogous soln. of the alkali... 

A few polymerizations leading to nonhydrolyzable polysaccharides have been reported. The first was a base-catalyzed polymerization of 5,6-anhydro-l,2-0-isopropylidene-3-0-methyl-a-D-glucofuranose.u The polymerization was initiated most successfully with solid potassium or cesium hydroxide, and the d.p. achieved was —25. Hydrolysis gave a free, methylated, nonhydrolyzable polysaccharide, which was oxidized with hypoiodite to the poly(D-gluconic acid.)... 

Ans. ia) Magnesium hypoiodite ib) iron(III) sulfate or ferric sulfate (c) calcium manganate id) potassium perrhenate (e) calcium mngstate if ) cobalt(II) carbonate... 

Another word of caution should be added at this point. Dimler and Link26 observed that during the oxidation of D-ribose with alkaline hypoiodite in methanol an epimerization occurred to the extent of about 5%, the insoluble potassium D-arabonate precipitating with the potassium... 

The reaction is the same as that involved in the usual chemical preparation of iodoform, whereby a colorless solution of hypoiodite (obtained by dissolving iodine in a sufficient quantity of potassium-hydroxide solution) is made to react with alcohol. The decomposition potential of potassium iodide, investigated by Dony-Henault,2 show s that the iodine as such does not act on the alcohol, but only after its conversion into hypoiodite. The iodine ions are set free at the same anode potential no matter if alcohol is added or not. The alcohol does not act as a depolarizer towards the iodine ion the electrical iodoform synthesis is a typical secondary process. 

Iodoform2 from Acetone.—Teeple3 mentions a method by which almost the theoretical yield of iodoform can be obtained by the electrolysis of a potassium-iodide solution in the presence of acetone. No diaphragm is required, the essential feature being the gradual addition of a substance like hydrochloric acid, hydriodic acid, or, better, iodine, to neutralize the excess of potassium hydroxide as fast as it is formed. The tempera-, ture is kept below 25°, and the electrolyte thoroughly stirred in fact the same current conditions should be observed as in the case of chloroform above mentioned, the aim in this case also being to maintain the conditions always favorable for the production of a maximum amount of hypoiodite. 

Potassium iodide m aqueous solution is oxidised to free iodine, the reaction having been extensively applied in the early historv of ozone, but it has now somewhat lost in favour because a similar effect can be produced by nitrogen peroxide or chlorine.3 If the action of the ozone is prolonged, the oxidation may proceed further to the formation of hypoiodite, iodate, and periodate.3... 

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