Gold monochloride

The tetraphenylarsonium salt of tetraazidoaurate(III) is made from 2.5 mmole potassium chloroaurate, KAuCU, which is dissolved in a small quantity of water. One hundred mmole of sodium azide is added to obtain a red solution. After filtering, tetraphenylarsonium chloride is added to precipitate the orange complex. It is recrystallized from acetone-water, or methylene chloride-hexane mixtures [139]. The colorless tetraphenylarsonium salt of diazidoaurate(I), [Ph4As] [Au (N3)2], is obtained by reacting a suspension of freshly prepared gold monochloride, AuCl (0.2 g = 0.9 mmole), and sodium azide (1.5 g = 23 mmole) in water-wet methylene chloride. Upon addition of... 

Halides. Gold(III) chloride [13453-07-1] can be prepared directiy from the elements at 200°C (167). It exists as the chlotine-bridged dimer, Au2Clg ia both the soHd and gas phases under an atmospheric pressure of chlorine at temperatures below 254°C. Above this temperature ia a chlorine atmosphere or at lower temperatures ia an iaert atmosphere, it decomposes first to AuCl [10294-29-8] and then to gold. The monochloride is only metastable at room temperature and slowly disproportionates to gold(0) and gold(III) chloride. The disproportionation is much more rapid ia water both for AuCl and the complex chloride, [AuCy, formed by iateraction with metal chlorides ia solution. 

It may be prepared in the laboratory by the reaction of iodine monochloride with metallic gold ... 

Selenium and tellurium are converted into their respective tetrachlorides by thionyl chloride, whilst gold, mercury, bismuth, arsenic, antimony, tin and iron give a mixture of the metallic chloride with sulphur dioxide and sulphur monochloride,2 for example ... 

Laboratory from metallic gold and iodine monochloride Gutmann, Z. Anorg. Allgem. Chem. 264, 169 (]95l). 

Iodine bromide converts various metals into the bromides its reactivity is smaller than that of iodine monochloride. Arsenic(III) bromide reacts with the oxides of lead, gold or copper to give the respective bromides ... 

One method which gave a purification of iodine-131 from a 16-day-old solu-tion of 10 fissions had the following steps (224). Iodide, iodate, or periodate carrier and sodium chlorate were added to the sample which contained only inorganic substances (but no gold) and no reducing agents. The solution was made 6-10 in hydrochloric acid in order to produce iodine monochloride (yellow-green solution). The monochloride was extracted into butyl acetate and then back-extracted into water as iodide by means of sulfurous acid. Iodide was oxidized to elemental iodine with iron(III) chloride in dilute sulfuric acid and the iodine extracted into toluene. The element was back-extracted into water as iodide by sulfurous acid and palladium(II) iodide was precipitated. 

If gold was present in the fission product solution, the iodine was converted to the monochloride as described above and the solution was boiled to expel excess chlorine. Then sufficient sulfurous acid was added to reduce gold (III) to the free element and iodine monochloride to iodide. After removal of the gold and excess sulfur dioxide, sodium chlorate was added and the solution made 6 M in hydrochloric acid. Then the procedure was taken up at the point where the iodine monochloride was extracted into butyl acetate. 

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