Ammonium pentasulphide

Ammonium pentasulphide, (NH4)2S5.—J. Fritzsche prepared this salt by... 

The simplest method, in practice, for the production of the alkali polysulphides is supplied by the interaction of sulphur and the alkali sulphide in hot aqueous or alcohol solution.2 Liver of sulphur, obtained by fusing sulphur with potassium carbonate,3 is, when freshly prepared, mainly a mixture of potassium polysulphides with potassium thiosulphate. Solutions of the hydroxides of the alkali or alkaline earth metals also dissolve sulphur, yielding solutions of the polysulphides and thiosulphates of the corresponding metals (see p. 87). When a suspension of sulphur in aqueous ammonia is treated with hydrogen sulphide in the absence of air, a red solution is obtained, which on cooling yields yellow crystals of ammonium pentasulphide, (NH4)2S5.4 Bloxam claimed 5 to have separated tetra-, penta-, hepta- and nona-sulphides in this way, whilst Thomas and Riding,6 using alcoholic ammonia, obtained only what they considered to be di-, penta- and hepta-sulphides. Mills and Robinson, however, were unable to obtain evidence of the formation of any polysulphide other than the pentasulphide. 

The pentasulphide, H2S5, has been isolated more recently4 by decomposing pure anhydrous ammonium pentasulphide with anhydrous formic acid (see p. 70). 

Ammonium thiocarbonate, (NH4)2CS3, may be prepared by digesting ammonium pentasulphide with carbon disulphide under a reflux condenser a white deposit of ammonium monosulphide first forms on the condensing surface and is gradually converted into the thiocarbonate, becoming pale oiange-coloured. On exposure to moist air it turns red. 

The ammonium salt may be obtained by extracting ammonium pentasulphide with carbon disulphide in a Soxhlet apparatus, washing first with hot carbon disulphide and then with ether, and centrifuging.4... 

The reaction must be carried out in an indifferent solvent. Thi.s compound forms yellowish-white crystals, M.pt. 200° C., is readily soluble in carbon disulphide, chloroform, and absolute alcohol, sparingly soluble in petroleum ether or benzene and insoluble in ordinary ether. With water it yields triphenylarsine oxide, and with hydrogen sulphide or ammonium pentasulphide gives triphenylarsine sulphide. Studies of... 

Hexamethyltri-4-aminotriphenylarsine sulphide, [(CH5)jN. CjHJjAsS. — The addition compound of the arsine with sulphur mono-chloride when treated with ammonium pentasulphide, (NH4 )2Sb, jields this sulphide. It crj stallises in plates, M.pt. 269° to 270° C., readily soluble in chloroform, sparingly soluble in other solvents. 

Pure anhydrous ammonium pentasulphide when treated with anhydrous formic acid gives H2S5 (Mills and Robinson, 1928). All the liquids readily decompose to HgS and sulphur. They dissolve in solvents like benzene and chloroform. Their structures involve chains of sulphur atoms. 

Ammonium heptasulphide, (NH4)2S7— J. Fritzsche reported that crystals of this salt are formed by the spontaneous vaporization of crystals of the penta-snlphide melting crystals of the pentasulphide in their own mother liquid, and... 

Under these conditions W. P. Bloxam obtained crystals of sulphur and of the pentasulphide, but no ruby-red crystals of the heptasulphide, and he obtained the enneasulphide by working according to J. Fritzsche s directions. P. Sabatier claims to have made the heptasulphide by digesting sulphur with the warm or cold mother liquid remaining after the separation of crystals of the pentasulphide. P. Sabatier s analysis corresponds with ammonium octomlpkide, (NH Sg. W. P. Bloxam made crystals of the hydrated salt, (NH4)2S7.fH20, by the simultaneous action of sulphur and hydrogen sulphide on aqua ammonia rather more cone, than that used in the preparation of the pentasulphide. 

The pentasulphide is violently oxidised by concentrated nitric acid, with formation of sulphuric acid, whilst dilute hydrochloric or sulphuric acid yields the ammonium salt and sulphur. 

Ammonium Thioarsenates. — Ammonium Orthothioarsenate, (NH4)3AsS4, separates as colourless prisms when alcohol is added to a hot solution containing arsenic pentasulphide and excess of ammonium hydrosulphide.5 The crystals gradually turn yellow in air and, when heated, melt and decompose, yielding ammonium sulphide, arsenious sulphide and sulphur. 

Arsenious sulphide is completely precipitated from a hot acid solution of an arsenite, and arsenic pentasulphide from one of an arsenate, by the addition of sodium thiosulphate, whilst both arsenites and arsenates are precipitated quantitatively as arsenious sulphide by ammonium thioacetate.6... 

According to A. Stock and B. Hoffmann, phosphorus pentasulphide and ammonia at ordinary temp, form a yellow addition product, P2S5.6NH8, and at —20°, a colourless addition product P2S5.7NH3. The hexammine is considered to be ammonium diimidopentathiodiphosphate ... 

A. Stock and co-workers obtained impure diimidopentathiodiphosphoric acid, S P(SH)2 NH 2) by heating imidotrithiophosphoric acid for a long time at 210°. It is suggested that phosphoryl diimidosulphide, S PS(NH)2 2, is formed as an intermediate product of the decomposition at about 100°. They obtained ammonium diimidopentathiodiphosphate, S P(SNH4)2 (NH) 2, by the action of ammonia at ordinary temp, on phosphorus pentasulphide and also by adding... 

A retrosynthetic analysis of (50) and (52) involving disconnection at both carbon-heteroatom bonds reveals hexane-2,5-dione as the four-carbon fragment needed for ring assembly ring construction is thus of type (45). The most convenient reagents for the appropriate heteroatom synthons are ammonium carbonate and phosphorus pentasulphide (Expts 8.11 and 8.13). 

Di- and Tri-imido- and -amido-thiophosphates.—A great variety of these compounds, chiefly in the form of their ammonium salts, was obtained by the action of ammonia, usually in the liquid form, on phosphorus pentasulphide.5 Some of the ammonia could be driven off by heating under reduced pressure, leaving the acid salts. 

Arsenic pentasulphide, like the trisulphide, is readily soluble in alkali hydroxides or ammonia (a), ammonium sulphide (b), ammonium polysulphide... 

Hydrogen sulphide orange-red precipitate of antimony pentasulphide, Sb2S5, in moderately acid solutions. The precipitate is soluble in ammonium sulphide solution (yielding a thioantimonate) in alkali hydroxide solutions, and is also dissolved by concentrated hydrochloric acid with the formation of antimony trichloride and the separation of sulphur. The thio-salt is decomposed by acids, the pentasulphide being precipitated. 

Dimolybdenum Pentasulphide is obtained as a trihydrate, by reducinfr with zinc a solution of ammonium molybdate... 

Uranium Oxysulphide, U3O2S4 or UO3.2US2, is formed when uranous oxide, urano-uranic oxide, or ammonium uranate is heated in a stream of hydrogen sulphide or carbon disulphide vapour when one of the oxides is heated with a mixture of ammonium chloride and sulphur or when uranyl sulphate is heated in hydrogen or with potassium pentasulphide. It is a greyish-black powder, which is decomposed by nitric acid %vith deposition of sulphur. 

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