| Phosphorus Subselenide, P4Se, may be prepared by heating one atomic proportion of selenium with at least four atomic proportions of phosphorus in the presence of an inert gas. The product obtained may contain a little red phosphorus which can be got rid of by filtration. Phosphorus subselenide is a yellow oily liquid which crystallises at -12° C. and is soluble in carbon disulphide. It is spontaneously inflammable in air and is decomposed by alkalis on heating, with liberation of phosphine. |