Auric bromide

Reaction with potassium bromide yields potassium auric bromide and potassium chloride with separation of metalhc gold ... 

It is suggested that substances such as potassium cliloraurate are dissociated first by ammonia into simple halides, for the alkali clilor-aurates and bromaurates behave towards ammonia like the auric salts.2 Auric bromide, obtained by dissolving precipitated gold in bromine, also absorbs ammonia, the amount depending on the temperature. 

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 ... 

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... 

Auribromides of sodium, barium, zinc, manganese,12 and magnesium18 have been prepared. Triple bromides of gold, silver, and rubidium (or caesium) have also been described.14 Double compounds of auric bromide and phosphorus derivatives can be obtained by methods analogous to those employed for the corresponding chlorine addition-products.15... 

Derivation By dissolving auric bromide in hydro-bromic acid, concentration, and crystallization. 

Perman2 exposed solid cupric nitrate and sulphate and auric chloride, contained in quartz vessels at a pressure of 0-1 mm., to the action of radium bromide for four months, but in no instance could the development of lithium be detected by the spectroscope. 

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... 

Metallurgy of gold. Aurous chloride, aurous bromide, aurous iodide, potassium aurous cyanide, auric chloride, hydrogen aurichloride. 

Tetrabenzylphosphonium iodide, (CgHg.CH2)4PI, occurs when one part of phosphonium iodide and two parts of benzyl alcohol are heated together for six to eight hours in a sealed tube at 100° C. It forms white crystals, M.pt. 191° C., readily soluble in chloroform, ether or alcohol, becoming slightly yellow on exposure to the air. This iodide may be transformed in the usual manner into the chloride, bromide, sulphate or nitrate, all of which form white, shining crystals. Double salts are obtained with platinic chloride, and auric, mercuric and stannic chlorides. A picrate is known. 

---