Nickel(II) iodide

Nickel(II) iodide

Nickel(II) iodide hexahydrate, NiI2•6H2O
Nickel(II) iodide
Names
IUPAC name Nickel(II) iodide
Other names Nickelous iodide
Identifiers
CAS Number	13462-90-3 Y
Jmol 3D model	Interactive image
PubChem	26038
InChI InChI=1S/2HI.Ni/h2*1H;/q;;+2/p-2
SMILES [Ni](I)I
Properties
Chemical formula	I2Ni
Molar mass	312.50 g·mol−1
Appearance	iron-black solid (anhydrous) bluish-green solid (hexahydrate)
Density	5.384 g/cm3
Melting point	780 °C (1,440 °F; 1,050 K) (anhydrous) 43 °C (hexahydrate, loses water)
Solubility in water	124.2 g/100 mL (0 °C) 188.2 g/100 mL (100 °C)
Solubility	alcohols
Vapor pressure	{{{value}}}
Related compounds
Other anions	nickel(II) chloride, nickel(II) bromide, nickel(II) fluoride
Other cations	cobalt iodide, copper iodide,
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Nickel(II) iodide is an inorganic compound with the formula NiI₂. This paramagnetic black solid dissolves readily in water to give blue-green solutions of the aquo complexes. This blue-green colour is typical of hydrated nickel(II) compounds. Nickel iodides find some applications in homogeneous catalysis.

Structure and synthesis

The anhydrous material crystallizes in the CdCl₂ motif, featuring octahedral coordination geometry at each Ni(II) center. NiI2 is prepared by dehydration of the pentahydrate.

NiI₂ readily hydrates, and the hydrated form can be prepared by dissolution of nickel oxide, hydroxide, or carbonate in hydroiodic acid. The anhydrous form can be produced by treating powdered nickel with iodine.

NiI₂ has found some industrial applications as a catalyst in carbonylation reactions. It is also has niche uses as a reagent in organic synthesis, especially in conjunction with samarium(II) iodide.