Aurous, auric

SbCh]-----and [ShCle]". Crystals of cesium aurous auric chloride,... 

Hydrogen aurichloride can be obtained as a yellotc crystalline substance, which forms salts with bases. When heated it forms auric chloride, AuClg, and then an aurous auric chloride, Au.,Cl, and then aurous chloride, AuCl. On further heating all the chlorine is lost, and pure gold remains. 

The crystal structure of cesium aurous auric chloride, Cs2AuAuCl6, and cesium argentous auric chloride, Cs2AgAuCl6. J. Am. Chem. Soc. 60 (1938) 1846-1851. (Norman Elliot and Linus Pauling). 

Gold-hydroxyd, n. gold hydroxide, specif, auric hydroxide, gold(III) hydroxide, -jodid, n. gold iodide, specif, auric iodide, gold(III) iodide, -jodiir, n. aurous iodide, gold (I) iodide, -kafer, m. gold beetle. 

The range of isomer shifts is larger for aurous, Au(l), than for auric, Au(lll), compounds, most probably due to the larger amount of -character in sp than in dsp hybrid orbitals, and also to the smaller variety of ligands in the auric compounds under study. 

The quadrupole splittings of the aurous compounds are generally larger than those of the auric compounds. 

Fig. 7.78 Linear relation of the quadmpole splitting A q = ( jl)eqQ (1 + j /3)l/2 and the isomer shift b for aurous (a) and auric (b) compounds. Also included is a correlation with the relative change in electron density at the gold nucleus, Ali/r(o)P, as derived from Dirac-Fock atomic structure calculations for several electron configurations of gold. An approximate scale of the EFG (in the principal axes system) is given on the right-hand ordinate (from [341])...

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. 

The Ammines of Corps , Silver, and Gold—Ammino-derivatives of Cupric Sulphate—Hydroxylamine-derivatives of Cupric Sulphate—Cupro-ammino-sulphates—Ammino-salts of Cuprio Halides—Ammino-ouprous Halides— Ammino-derivatives of Silver Halides—Ammino-derivatives of Silver Nitrate —Ammino-derivatives of Gold Salts—Aurous Halides—Auric Halides— Derivatives of Auric Oxide, Auric Nitrate, Anrie Phosphate, Perohlorate— Derivatives of Mixed Salts. 

AURIC AND AUROUS. Prefixes often used in the naming of gold salts of valence +i (ic) and +1 (ous). Thus, auric chloride, aurous nitrate, and so on. 

In aqueous solution the salts of the metals of Group I. must be classed as strong electrolytes, a statement also applicable to the hydroxides of the univalent cations, except aurous hydroxide, AuOH. This hydroxide shares with cupric hydroxide and auric hydroxide a weak basic character, solutions of their salts having an acidic reaction, due to hydrolytic dissociation. 

Awrous Ion.—This ion is known almost exclusively in the form of complex anions of the type Au(CN)2. Aurous compounds are converted by water into auric compounds, with separation of metallic gold, a reaction facilitated by the presence of halogen ions, complex derivatives of auric ion being formed ... 

In 1819 Pelletier 2 found Au=288 by analysing aurous iodide. Two years later, Javal3 found Au=201 by analysing auric oxide, and Au=104 by analysing potassium aurichloride. In 1823 Figuier4 found Au = 179 from the analysis of sodium aurichloride. These very inaccurate results are in striking contrast to Berzelius s value. 

Aurous chloride, AuCl.—Partial elimination of chlorine from auric chloride by means of heat yields aurous chloride, but it is difficult to... 

The chloride2 is a yellowish-white substance, soluble in aqueous alkali-metal chlorides 3 with formation of complex anions, the solutions soon decomposing with precipitation of metallic gold and the formation of complex auric derivatives. The transformation is more rapid in bromide solutions. At 110° to 120° C. aurous chloride and excess of phosphorus trichloride combine to form a double compound of the formula AuCl,PCl3, colourless prisms insoluble in water.4... 

Aurous bromide, AuBr.—When auric bromide is heated, bromine is evolved, and aurous bromide left as a green mass.5 It is also formed by heating auribromic acid, HAuBr4, the auric bromide formed decomposing at 115° C. Above this temperature it is decomposed into gold and bromine, and reacts with water like aurous chloride. Aqueous hydro-bromic acid converts it into gold and auribromic acid, HAuBr4 ... 

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... 

Aurous cyanide, AuCN.—The cyanide is produced by the interaction of hydrogen cyanide and auric hydroxide8 by double decomposition... 

Auric bromide, AuBr3.—The bromide is formed in aqueous solution by the action of water on gold dibromide.14 It can be obtained in the solid state from the same source by the action of moist ether, the aurous bromide formed remaining undissolved, and auric bromide being left on evaporation of the dried ether solution. It is also produced by the interaction of aqueous bromine and gold,16 as well as by the action of solutions of such perbromides as cobalt tribromide, manganese tetrabromide, and ferric bromide on the metal.16 The aqueous solution and the crystals deposited from it have a scarlet-red colour, but the pure salt contained from solution in ether is a dark-brown... 

---