Molybdenum trisulphide, MoS3, is obtained by saturating a solution of an alkaline molybdate with sulphuretted hydrogen and adding a mineral acid.
Bismuth combines directly with sulphur to form a disulphide, B12S2, and a trisulphide, B12S3, the latter compound being formed when the sulphur is in excess.
Bismuth trisulphide, B12S3, constitutes the mineral bismuthite, and may be prepared by direct union of its constituents, or as a brown precipitate by passing sulphuretted hydrogen into a solution of a bismuth salt.
Bismuth forms compounds similar to the trisulphide with the elements selenium and tellurium.
When heated in a current of hydrogen it is transformed into the colourless disulphide, whilst if the heating be carried out in a current of nitrogen it yields the trisulphide, Rb 2 S 3 H 2 0.
The trisulphide, WS3, is obtained by dissolving the trioxide in ammonium sulphide or by passing sulphuretted hydrogen into a solution of a tungstate and precipitating by an acid in both cases.
The sodium salt on distillation with phosphorus trisulphide gives thiophene.
The sodium salt on heating with phosphorus trisulphide yields methylthiophen.
Antimony trichloride ("Butter of Antimony"), SbCl 31 is obtained by burning the metal in chlorine; by distilling antimony with excess of mercuric chloride; and by fractional distillation of antimony tetroxide or trisulphide in hydrochloric acid solution.
Two sulphides of antimony are definitely known, the trisulphide Sb 2 S 3 and the pentasulphide Sb2S5; a third, the tetrasulphide Sb2S4, has also been described, but its existence is doubtful.
Antimony trisulphide, Sb2S3, occurs as the mineral antimonite or stibnite, from which the commercial product is obtained by a process of liquation.
On precipitating antimony trichloride or tartar emetic in acid solution with sulphuretted hydrogen, an orange-red precipitate of the hydrated sulphide is obtained, which turns black on being heated to 200° C The trisulphide heated in a current of hydrogen is reduced to the metallic state; it burns in air forming the tetroxide, and is soluble in concentrated hydrochloric acid, in solutions of the caustic alkalis, and in alkaline sulphides.
By the union of antimony trisulphide with basic sulphides, livers of antimony are obtained.
On heating in absence of air, it decomposes into the trisulphide and sulphur.
Thiophosphoryl chloride, PSC1 3, may be obtained by the direct combination of sulphur with the trichloride; from sulphuretted hydrogen and the pentachloride; from antimony trisulphide and the pentachloride; by heating the pentasulphide with the pentachloride; and by dissolving phosphorus in sulphur chloride and distilling the solution: 2P+3S 2 C1 2 = 4S+2PSC1 3.
ORPIMENT (auripigmentum), arsenic trisulphide, As2S3, or yellow realgar, occurring in small quantities as a mineral crystallizing in the rhombic system and of a brilliant goldenyellow colour in Bohemia, Peru, &c. For industrial purposes an artificial orpiment is manufactured by subliming one part of sulphur with two of arsenic trioxide.
The trichloride, VC1 31 is a deliquescent solid formed when the tetrachloride is heated in a retort as long as chlorine is given off (Roscoe), or by heating vanadium trisulphide in a current of chlorine and fractionally distilling the resulting product at 150° C. in a current of carbon dioxide (Halberstadt, Ber., 1882, 15, p. 1619).
In the wet way, arsenious oxide and arsenites, acidified with hydrochloric acid, give a yellow precipitate of arsenic trisulphide on the addition of sulphuretted hydrogen; this precipitate is soluble in solutions of the alkaline hydroxides, ammonium carbonate and yellow ammonium sulphide.
1861, 113, p. 134) by converting arsenic trisulphide in hydrochloric acid solution into arsenic pentasulphide also obtained 75.0.
On acidifying the solution so obtained with hydrochloric acid, the whole of the arsenic is reprecipitated as trisulphide, K2HAsO3 + K2HAsS3 + 4HCl = 4KCl + 3H2O + As2S3.
Arsenic pentasulphide,As2S5, can be prepared by fusing the trisulphide with the requisite amount of sulphur; it is a yellow easily-fusible solid, which in absence of air can be sublimed unchanged; it is soluble in solutions of the caustic alkalis, forming thioarsenates, which can also be obtained by the action of alkali polysulphides on orpiment.
It may be obtained in small quantity by passing ethylene or acetylene into boiling sulphur; by passing ethyl sulphide through a red-hot tube; by heating crotonic acid, butyric acid or erythrite with phosphorus pentasulphide; by heating succinic anhydride with phosphorus pentasulphide or sodium succinate with phosphorus trisulphide (J.
Erdmann, Ber., 1885, 18, p. 454); or by heating succindialdehyde with two parts of phosphorus trisulphide (C. Harries, Ber., 1901, 34, p. 1496).