Iodine-containing compounds potassium iodide

The iodoso- and, in particular, the iodoxy-compounds decompose with a puff when heated, since the oxygen which they contain is present in a state of tension. They liberate an equivalent amount of iodine from acidified potassium iodide solution and are thereby reconverted into iodobenzene. 

By use of between 0.1% and 1% of a non-ionic surfactant of HLB-value between 8 and 15 and surface tension less than 30 dyne/cm, poly(vinyl fluoride) emulsions with particle diameter less than 5 /im have been prepared at 30°-45°C [54]. Procedure 2-6 is a patented process given here for reference only. It is of interest because the incorporation of an iodine-containing compound such as ammonium iodide, 2,2 -azobisisobutyramidine hydroiodide, potassium iodide, iodine in isopropanol, isopropyl iodide, tetraiodoethylene in tert-butanol, iodo-benzene, 2-iodothiophene, or ethyl iodide give rise to polymers of improved thermal stability and resistance to color deterioration [55]. The process does not seem to involve the use of an emulsifying agent. 

In a procedure described in Ref. [474], sodium orthosilicate was added to the reaction medium to raise the polymer yield to 95%. The initiator was ammonium persulfate with a special emulsifier that is believed to be perfluorinated carboxylated emulsifier from 3M Corp [458]. Other initiators used are redox systems such as potassium persulfate-sodium metabisulfite or ammonium persulfate-sodium sulfite [475]. Different initiators are also of some interest because they affect the particle diameter of the emulsion. Polymer particles formed with a diameter between 0.36 and 18 pm, depending on the initiator system and the polymerization procedures, are reported [458]. In a patent of Dynamit Nobel [476], iodine-containing compounds such as ammonium iodide or isopropyl iodide are used. These compounds give rise to polymers of improved thermal stability and resistance to color deterioration. The procedure did not require the use of an emulsifier. After 150 min the internal pressure of the autoclave dropped from 2 x 10 to 3 X 10 Pa and a conversion to polymer of 86% was found. More recently Uschold [477] describes also an emulsion polymerization of PVF in high yields and having excellent color. 

Compound Paint of Iodine, B,P.C. (Mandl s Paint). A mixture of iodine in strong potassium iodide solution diluted with glycerin it also contains alcohol and peppermint oil. It contains T25 per cent w/v iodine and 2 50 per cent w/v potassium iodide. 

Iodine as such finds few uses but a solution in alcohol and water, also containing potassium iodide ( tincture of iodine was commonly used as an antiseptic for cuts and wounds, but had rather an irritant action. Iodoform (triiodomethane), CHI3, is also an antiseptic, but newer compounds of iodine are now in use. Silver iodide, like silver bromide, is extensively used in the photographic industry. 

Iodine compounds are important in organic chemistry and very useful in medicine. Iodides, and thyroxine which contains iodine, are used internally in medicine, and as a solution of KI and iodine in alcohol is used for external wounds. Potassium iodide finds use in photography. The deep blue color with starch solution is characteristic of the free element. 

A brown additive compound of iodine with the dibromo compound may separate during the titration this compound usually dissolves during the subsequent titration with thiosulphate, yielding a yellow solution so that the end point with starch may be found in the usual manner. Occasionally, the dark-coloured compound, which contains adsorbed iodine, may not dissolve readily and thus introduces an uncertainty in the end-point this difficulty may be avoided by adding 10 mL of carbon disulphide before introducing the potassium iodide solution. 

Of the many tests which have been submitted, the determination of active oxygen or peroxide content seems to give rather good correlation of data. During the oxidation of fat, certain oxygen-containing compounds are formed which are active in the sense that they are capable of liberating iodine from potassium iodide (19). The liberated iodine may be determined quantitatively and it thus becomes a measure of rancidity. 

Isoxazoles have been used to transpose functionality within a,/3-unsaturated carbonyl compounds (72JA9128). Thus, on exposing either (E)- or (Z)-/3-ionone oxime (449) to a mixture of iodine-potassium iodide in hot aqueous THF containing sodium bicarbonate, the isoxazole (450) was formed in high yield. Catalytic reduction of this isoxazole led... 

Oxyiodide.— By heating vdth potassium iodide a solution of a molybdate in hydrochloric acid, a dark red liquid containing the compound M0O2I is obtained, with elimination of iodine (see p. 179). ... 

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