Tungsten Monophosphide, WP

Tungsten Monophosphide, WP is prepared by heating the diphosphide WP₂ (1 part) with copper phosphide (20 to 30 parts) at 1200° C. for three or four hours with careful exclusion of air; the resulting mass is treated with dilute nitric acid, and the phosphide remains in the form of grey lustrous prisms of density 8.5. The compound is stable in air and behaves in a similar manner to the diphosphide towards oxygen, the halogens, acids, and alkalies, but it may be heated in hydrogen to 900° C. without reduction taking place.