Tungsten Diiodide is an inorganic compound with the molecular formula WI₂ and a relative molecular mass of 437.7. It is a metal salt of tungsten and hydroiodic acid, characterized by black or dark brown crystals, usually in powder or lump form. Tungsten diiodide has good solubility in alkalis but is insoluble in cold water, ethanol, and carbon disulfide. It has a density of 6.79 g/cm³ and a melting point of about 300°C, which allows it to remain stable at everyday ambient temperatures.

Tungsten diiodide ( WI₂) is the iodide of tungsten (II), which is the metal salt of tungsten and hydroiodic acid. Its English name is Tungsten Diiodide, CAS number : 13470-17-2, relative molecular mass : 437.65.

The solubility of tungsten diiodide has no specific pattern. For inorganic solvents, tungsten diiodide is soluble in alkali but insoluble in water at room temperature; for organic solvents, tungsten diiodide is insoluble in ethanol and carbon disulfide (CS₂).

Tungsten diiodide(IUPAC name: Tungsten Diiodide, molecular formula:WI₂) is an inorganic compound composed of tungsten and iodine after chemical reaction. The valence electron configuration of tungsten atom in tungsten diiodide is 5d⁴6s², which can form compounds with oxidation value from +2 to +6. Among them, the compounds with oxidation value of +6 are more stable. In tungsten diiodide, the valence state of tungsten is +2, and iodine is -1. So the molecule is composed of one tungsten atom and two iodine atoms.