Phosphorus oxysulphides

Phosphorus Oxysulphides.—The compound P406S4 was prepared by heating together P406 and sulphur in an atmosphere of nitrogen or carbon dioxide —... 

Phosphorus and Sulphur —Historical—Physical Mixtures—The System Phosphorus-Sulphur and Compounds—Tetraphosphorus Trisulphide—Diphosphorus Trisulphide — Tetraphosphorus Heptasulphide — Phosphorus Pentasulphide—Uses of the Sulphides of Phosphorus—Oxysulphides—Thio-phosphites, Thiohypophosphates and Thiophosphates. 

A number of phosphorus oxysulphides have been well characterised and there is evidence for the existence of many more. 

Phosphorus combines directly with sulphur in various proportions to give sulphides, the formulae of some of which resemble those of the oxides. It also gives oxysulphides, thiophosphites, thiophosphates and the corresponding acids. The latter salts may be made by the action of alkalies or alkali sulphides on phosphorus sulphides. 

Since the sulphides, oxysulphides and halosulphides of phosphorus are completely hydrolysed by water with evolution of H2S, it is evident that the thioxyacids of phosphorus are unstable. Various salts of these acids may however be prepared by using alkalies or ammonia instead of water and by other reactions, of which a general outline only is given here. 

Phosphorus trioxide reacts violently with chlorine or bromine to produce the corresponding phos-phoryl halides (4.72). With hydrogen chloride, phosphorous acid is obtained (4.208). In carbon disulphide under pressure, the diiodide is formed (4.73). Addition of sulphur readily takes place to give an oxysulphide, P4O5S4 (4.74), and with ammonia, phosphonic diamide may be the product (7.63). 

A.R Childs, Phosphorus sulphides and oxysulphides, in Mellor s Comprehensive Treatise on Inorganic and Theoretical Chemistry, No. 8, Supp. 3, Longmans, London, 1971. 

A general approach to both saturated and unsaturated thioesters consists of reaction between phosphorus ylides and carbon oxysulphide (Scheme 46). °... 

---