Tungsten(III) iodide or tungsten triiodide is a chemical compound of tungsten and iodine with the formula WI₃.

Preparation

Tungsten(III) iodide can be prepared by reducing tungsten hexacarbonyl with iodine.^[1][3]

${\displaystyle \mathrm {2\ W(CO)_{6}+3\ I_{2}\longrightarrow 2\ WI_{3}+12\ CO} }$

Properties

Tungsten(III) iodide is a black solid that releases iodine at room temperature, and is less stable than molybdenum(III) iodide. It is soluble in acetone and nitrobenzene, and slightly soluble in chloroform.^[1]

It decomposes to form tungsten(II) iodide:^[1]

${\displaystyle \mathrm {6WI_{3}\longrightarrow [W_{6}I_{8}]I_{4}+3I_{2)) }$