Iodine sources

Salt has been a precious commodity throughout most of human history. Rome s armies were paid in salt, which Mral is the origin of the word salary. Salt is a seasoning, an essential nutrient, and a very important preservative. Table salt is sodium chloride combined with iodine sources (for nutrition), stabilizers for the iodine, and anticaking compounds to prevent it from absorbing water from the air so it can pour freely. 

Recently, Duirk et al. [34] showed evidence that iodinated X-ray contrast media (ICM), such as iopamidol, constitute an iodine source to form iodo-THM DBFs, e.g., dichloroiodomethane, and iodo-acid DBFs, e.g., iodoacetic acid, in chlorinated and chloraminated drinking waters. However, the complete reaction pathway is not fully understood yet, and it is under further investigation. Chloraminated and chlorinated source waters with iopamidol were genotoxic and cytotoxic in mammalian cells. This is in agreement with the previously reported high genotoxicity and cytotoxicity of the iodo-acids and iodo-THMs [20, 21]. 

Of the common alkyl polyamines, ethylenediamine is the most notable because of its widespread use and toxicity. Although it has a toxicity rating of only three, it can be very damaging to the eyes and is a strong skin sensitizer. The dihydrochloride and dihydroiodide salts have some uses as human and veterinary pharmaceuticals. The former is administered to acidify urine, and the latter as an iodine source. Putrescine is a notoriously odorous naturally occurring substance produced by bacteria in decaying flesh. 

The use of iodoetherification has been exploited in the synthesis of precursors to mono- and bis-THF acetogenins,234 potent antitumor and pesticides. Also, has been used in the synthesis of tetrahydrofuran analogs of precursors to pseudomonic acid.235 As well, N1S has been used as the iodine source, for example in the synthesis of other acetogenins.236 Other compounds synthesized via iodocyclization include ( )-(a)-multistriatin,237 ( )-velbanamine, and ( )-isovalbanamine,238 and (+)-citreoviral.239... 

Iodination of alkanes using iodine (I2) is usually an unfavorable reaction. (See Problem 4-17, for example.) Tetraiodomethane (CI4) can be used as the iodine source for iodination, in the presence of a free-radical initiator such as hydrogen peroxide. Propose a mechanism (involving mildly exothermic propagation steps) for the following proposed reaction. Calculate the value of AH for each of the steps in your proposed mechanism. 

Ozeki, N., Shimomura, N., Harada, H. A new Sandmeyer iodination of 2-aminopurines in non-aqueous conditions combination of alkali metal iodide and iodine as iodine sources. Heterocycles 2001, 55,461-464. 

Cream-colored, almost odorless powder. Practically insol in water or alcohol sol in benzene, chloroform, ether. therap cat Iodine source. 

White, crystalline powder, mp about 275 with decompn, but becomes brown at 240". Freely sol in water, slightly ia alcohol. Practically insol in ether, acetone. thexap CAT Iodine source. 

Figure 11.2 Distribution of in different fractions of Chernobyl soil and Irish Sea sediment. From left to right, the fractions generally increase in the strength with which they bind iodine. Source. Hou et al., (2003) reproduced with permission from Elsevier.

---