Addition of iodine cyanide

Perfluoroalkylalkynes undergo unidirectional syn addition of iodine cyanide [M] (equation 43)... 

Sometimes, when tho process is conducted in tho manner just described, cyanide of iodine is produced, and is found in the third receiver in white needle-shaped crystals. The residue In the retort still retains some iodine In the form of iodide of lead and sodium. This can bo recovered by tho method proposed by Soubetean—namely, the addition of sulphate of copper, by which a subiodido of copper is formed. The precipitate is filtered, and the filtrate, which still retains some iodine, treated with a further quantity of tbo cupreous salt and iron filings, when another interchange takes place, and a further precipitation of iodide of copper occurs. Tho first of these changes may be expressed thus... 

An expedient method for the preparation of isochromene carboxylates (203) has been developed, which relies on the regioselective 1,6-addition of various nucleophiles, such as Grignard reagents, alkoxides, and cyanide, to benzopyranylidenetungsten(O) complexes (201), followed by iodine oxidation of the addition intermediates (202)254 DFT calculations have been carried out to rationalize the unusual switch in stereoselectivity, where ynone and ynoate substrates exhibit opposite stereochemical preferences in the stannylcupration.255... 

Halogens. Acidify about 2 mL of the FAQS by dropwise addition of 6 M nitric acid. Working at the hood, boil the solution gently for 2-3 min to expel any hydrogen sulfide or cyanide that may be present. Cool the solution and then add several drops of 0.3 M aqueous silver nitrate solution. A heavy precipitate of silver halide indicates the presence of chlorine, bromine, or iodine in the original organic compound. A faint turbidity of the solution should not be interpreted as a positive test. 

Whilst numerous literature methods exist to separate chlorine and iodine, many of these are not ideal for a commercial laboratory. They often rely on the use of relatively hazardous chemicals that require particular means of disposal, such as carbon tetrachloride in solvent extraction methods . In addition, the processes can be labour intensive, such as methods employing a speciation change of iodine as well as solvent extraction washes with chemicals such as sodium metabisulfite (Na2S205) °. In addition the dissolution of Agl in order to provide a more suitable medium for liquid scintillation counting can present difficulties as many of the techniques for dissolving Agl involve the use of relatively hazardous chemicals such as alkali cyanides, or the chemicals (and/or their required concentrations) are not compatible with liquid scintillation cocktails. 

In addition to anion adsorption, there exists the possibility of adsorption of cations at negative potentials along with coadsorption phenomena. For example, mixed layers of alkali cations with iodine on Au(llO) [291] or cyanide on Pt(lll) [292] have been reported. In fact, coadsorption has proven to be quite common among numerous underpotential metal deposition reactions as described below. 

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