The compound P4O6S4 was prepared by heating together P4O6 and sulphur in an atmosphere of nitrogen or carbon dioxide:—
P4O6 + 4S = P4O6S4
It appears as colourless rectangular prisms which melt at about 102° C. and boil at 295° C. The vapour density is 11.8 to 12.5 (air =1), which corresponds to the formula given. It is very easily soluble in CS2. In moist air it decomposes as follows:—
P4O6S4 + 6H2O = 4HPO3 + 4H2S
Another oxysulphide, also a derivative of P2O5, was produced when H2S dissolved in POCl3 containing carbon disulphide was allowed to react for some weeks at 0° C. Small needle-shaped crystals having the composition P2O2S3 then separated. They melted at about 300° C. and sublimed in a vacuum with decomposition. The compound was decomposed by moist air with production of H2S.
2POCl3 + 3H2S = P2O2S3 + 6HCl |