Tungsten(II) iodide

Source: Wikipedia, the free encyclopedia.
Tungsten(II) iodide
Identifiers
3D model (
JSmol
)
ChemSpider
  • InChI=1S/2HI.W/h2*1H;/q;;+2/p-2
    Key: BMKSRUJKNOBSHP-UHFFFAOYSA-L
  • [I-].[I-].[W+2]
Properties
I2W
Molar mass 437.65 g·mol−1
Appearance dark brown solid[1]
Density 6.79 g·cm−3[2]
Melting point 800 °C (decomposes)[2]
insoluble[2]
Related compounds
Other anions
tungsten(II) chloride
tungsten(II) bromide
Other cations
chromium(II) iodide
molybdenum(II) iodide
Related compounds
tungsten(III) iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Tungsten(II) iodide is an iodide of tungsten, with the chemical formula [W6I8]I4, or abbreviated as WI2.

Preparation

Tungsten diiodide can obtained from the decomposition from tungsten(III) iodide:[1]

6 WI3 → [W6I8]I4 + 3 I2

It can also be formed by the displacement reaction of tungsten(II) chloride and iodine:[1]

[W6Cl8]Cl4 + 12 I → [W6I8]I4 + 12 Cl

It can also be formed by the direct reaction of tungsten and iodine, which is a reversible reaction. This reaction can be used in halogen lamps.[3]

W + I2 ⇌ WI2

Tungsten(II) iodide can also be obtained by reacting tungsten hexacarbonyl with iodine.[4]

Properties

Tungsten(II) iodide is a dark brown-colored solid that is stable in air and moisture. Its structure is the same as tungsten(II) chloride, crystallising

lattice parameters a = 1258 pm, b = 1259 pm, c = 1584 pm.[1]

References