Tungsten Tetra-iodide, WI₄

Tungsten Tetra-iodide, WI₄, has been prepared by heating for two hours at 100° C. in a sealed tube a mixture of the hexachloride and liquefied hydrogen iodide. It is a black, crystalline, infusible substance which decomposes on volatilisation and has a density at 18° C. of 5.2. It is not completely stable in air; it is insoluble in water, ether, and chloroform.