Auric chloride oxide

Ammino-derivatives of Auric Salts and Oxides.—Auric chloride, like platinic chloride, combines with hydrochloric acid and alkali chlorides with formation of ehlorauric acid, HAuC14, and alkali chlor-... 

If dilute chloraurie acid containing ammonium chloride is added to a cold saturated solution of ammonium chloride saturated with ammonia only one compound is obtained, namely, diamino-auric chloride, Au(NH2)2C1. This is a yellow powder which is non-explosive and is decomposed by washing with water, forming a derivative of aurous oxide of composition 3Au0.2NH3.,dH20, which is explosive. 

Silver nitrate in ammoniacal solution may be completely reduced to silver by aqueous arsenious oxide. The reduction is hindered by the presence of ammonium sulphate, owing to the decrease in concentration of the hydroxyl ions 5 neutral salts such as sodium sulphate or sodium nitrate have no effect. Similarly, auric chloride may be reduced to gold.6 At 20° C. an aqueous solution of vitreous arsenious oxide reacts 4 to 5 times as rapidly as an aqueous solution of the octahedral form 7 the greater rate of dissolution in water of the former variety has been mentioned (p. 137), but from supersaturated solutions of the two forms there is no appreciable difference in the rates of deposition. The explanation of the inferior reducing power of the crystalline variety may be that there exist anisotropic molecules which only slowly lose their anisotropic properties. An ammoniacal solution of arsenious oxide heated with cupric sulphate in a sealed tube at 100° C. causes reduction... 

Aurous sulphide, Au2S.—The pure sulphide can be prepared7 by saturation of a solution of potassium aurocyanide with hydrogen sulphide, and precipitation of the salt by acidifying the solution with hydrochloric acid. It is not produced by the action of hydrogen sulphide on a hot solution of auric chloride, as supposed by Berzelius.8 The moist substance has- a steel-grey colour when dried, it becomes brownish black. When freshly prepared, the sulphide dissolves in water to a colloidal solution, from which it is reprecipitated by addition of hydrochloric acid. The sulphide is unaffected by dilute acids, but is decomposed by powerful oxidizers such as aqua regia and chlorine. It is readily dissolved by solutions of polysulphides,0 and less readily by those of monosulphides. It also dissolves in a solution of potassium... 

Compounds of Gold and Phosphorus.—Phosphine reacts with a solution of auric chloride in anhydrous ether, forming auric phosphide, AuP, a substance decomposed by water or potassium-hydroxide solution, with formation of phosphine and phosphoric add.2 At 100° to 110° C. it-undergoes oxidation in the air. Heating in a current of carbon dioxide causes volatilization of phosphorus. Nitric acid oxidizes the phosphorus, leaving a residue of metallic gold. These reactions indicate the substance to be an alloy of gold and phosphorus. 

Cacodylic acid is reduced to cacodyl when treated -with an excess of sodium hypophosphite in hydrochloric acid solution, Cacodyl may be obtained from dimethylarsine by the action of oxides of nitrogen, aqueous chromic acid, le peroxide, cacodyl chloride, auric chloride, or potassium ferricyanide. It also results w hen cv/cZopentamethyl-penta-arsine is distilled under atmospheric pressure in a carbon dioxide atmosphere, the decomposition commencing at 270° C. ... 

The quaternary iodides are crystalline compounds, form platini-chlorides, and with chlorine yield iododicMorides of the type R4ASI.CI2. Some aliphatic-aromatic arsonium iodides combine with metallic salts such as mercwic halides, auric chloride, and cadmiumiodide, whilst iodoform also forms addition compounds with some derivatives. Treatment of the iodides with a boiling suspension of silver chloride replaces the iodine by chlorine, giving R4ASCI. The latter also results when hydrochloric add is added to hydroxides of the type R4AS.OH. The hydroxides are derived from the iodides by boiling the latter with a suspension of silver oxide in water or alcohol. It is not always possible to isolate a crystalline product from this reaction, and the syrups often isolated soon absorb carbon dioxide from the air. 

Chloroauric acid (HAuCD) or auric chloride (AuCD or AU2CI6) is usually used but complex salts, such as potassium aurocyanide (KAu(CN)2) and the ethylenediamine complex [Au(en)2]Cl3, are alternatives. Traditional supports are silica, alumina and magnesia, but titania, alumina, boehmite (AIO(OH)), ferric oxide (a-Fe203) and magnesium hydroxide can also be used [18]. 

It is yeUow or red by reflected light, green by transmitted light, reddish-purple when flnely divided not veiyr tenacious softer than silver very malleable and ductile. It is not acted on by H,0 or air at any temperature, nor by any single acid. It combines directly with Cl, Br, I, P, Sb, As, and Hg. It dissolves in nitromuriatic acid os auric chloride. It is oxidized by alkalies in fusion on contact with air. 

Chloride, GdCl3, white monoclinic crystals, prepd by heating the oxide with excess of ammonium chloride above 200°. d° 4.52. mp about 609. Sol in water forms double salts with platinic and auric chlorides. A hexahydrate, GdCl .6HjO dehquesc crystals, d 2.424, is obtained from the aq soln. LE) in mice 550 mg/kg i p. > 2000 mg/kg orally, Haley, J, Pharm, Sci 84, 663 (1965). 

Gold, Explosive. Fulminating gold . An auric compd of nitrogen. Ohtained by the action of ammonia on auric chloride or ammonium chloride on auric oxide Ra-sebig. Ann. 235, 355 (1886) Weitz. An,. 410, 117 (1915). 

Oxidizing agents decompose HCl with liberation of Cl. A mixture of hydrochloric and nitric acids in the proportion of three molecules of the former to one of the latter, is the aoidum nitro-hydrochloricum U. S. Br. or aqua regia. The latter name alludes to its power of dissolving gold, by combination of the nascent Cl, which it liberates, with that metal, to form the soluble auric chlorid. 

Many metal chlorides when heated with an excess of nitric acid are converted into the nitrates. Thus, J. L. Smith found that the transformation occurs with potassium or sodium chloride in the presence of 7 to 8 parts of nitric acid J. S. Stas said that at 40°-50°, potassium, sodium, or lithium chloride require respectively 3, 4, and 5-5 parts of nitric acid. J. L. Smith said that ammonium chloride and nitric acid yield nitrous oxide. H. Wurtz found that auric, cadmium, cerium, lanthanum, didymium, ferric, and platinic chlorides are decomposed by nitric acid incompletely and with difficulty. S. Schlesinger said that the two copper chlorides, mercurous, zinc, and lead chlorides, are decomposed, but, added H. Wurtz, with difficulty and incompletely while mercuric ajid silver chlorides are not attacked. F. Rose found cobalt amminochlorides are readily converted into the nitrate. 

In the pure condition auric hydroxide resembles ferric hydroxide in appearance, and has the colour of brown ochre, but impurities impart to it a yellowish or greenish tint. It is soluble in nitric acid and hydrochloric acid, and in hot potassium-hydroxide solution, but insoluble in solutions of the carbonates of the alkali-metals and ammonium.6 It dissolves in solutions of the chlorides of sodium, potassium, and barium with production of complex salts.7 Prolonged heating at 140° to ISO0 C. eliminates all its water, with formation of auric oxide, Au2Oa. At 155° to 165° C. auric oxide is converted into gold monoxide, AuO.8... 

Oxidation numbers (I) and (III), as in AuCl, aurous chloride, and AU2O3, auric oxide. Most Au species, e.g., AuO or AuSe , are mixtures Au Au 2 or Au Au Sc2, etc. Liquid NH3 can yield Au in salt-like CsAu, stabilized by relativity. Relativity also makes metallic Au yellow. (Non-aqueous) F2 can produce [(Au F4)2(a-F)2]. 

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