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Zinc iodide is often used as an x-ray opaque penetrant in industrial radiography to improve the contrast between the damage and intact composite. [7] [8]United States patent 4,109,065 [9] describes a rechargeable aqueous zinc-halogen cell that includes an aqueous electrolytic solution containing a zinc salt selected from the class consisting of zinc bromide, zinc iodide, and mixtures thereof ...
This clock reaction uses sodium, potassium or ammonium persulfate to oxidize iodide ions to iodine. Sodium thiosulfate is used to reduce iodine back to iodide before the iodine can complex with the starch to form the characteristic blue-black color. Iodine is generated: 2 I − + S 2 O 2− 8 → I 2 + 2 SO 2− 4. And is then removed:
For example, iodomethylzinc iodide, formed in situ from diiodomethane and a zinc-copper couple reacts with cyclohexene to give norcarane (bicyclo[4.1.0]heptane). [1] An example of the Simmons-Smith reaction. Iodomethylzinc iodide may also be generated by the reaction of diazomethane with zinc iodide, or by the reaction of methylene iodide with ...
Thus, cyclohexene, diiodomethane, and a zinc-copper couple (as iodomethylzinc iodide, ICH 2 ZnI) yield norcarane (bicyclo[4.1.0]heptane). [5] [6]The Simmons–Smith reaction is generally preferred over other methods of cyclopropanation, [7] however it can be expensive due to the high cost of diiodomethane.
This makes analysis of hexacyanoferrate(III) troublesome as the iodide and thiosulfate decomposes in strongly acidic medium. To drive the reaction to completion, an excess amount of zinc salt can be added to the reaction mixture containing potassium ions, which precipitates the hexacyanoferrate(II) ion quantitatively:
The reaction is effected with zinc. The key zinc-intermediate formed is a carbenoid (iodomethyl)zinc iodide which reacts with alkenes to afford the cyclopropanated product. The rate of forming the active zinc species is increased via ultrasonication since the initial reaction occurs at the surface of the metal.
The Negishi coupling was implemented in the synthesis of δ-trans-tocotrienoloic acid by Hecht and Maloney coupling the sp 3 homopropargyl zinc reagent 8 with sp 2 vinyl iodide 9. [43] The reaction proceeded with quantitative yield, coupling fragments mid-synthesis en route to the stereoselectively synthesized natural product δ-trans ...
Of the halides, iodide usually is the best leaving group. Because of the weakness of the C–I bond, samples of organoiodine compounds are often yellow due to an impurity of I 2. A noteworthy aspect of organoiodine compounds is their high density, which arises from the high atomic weight of iodine.