Nickel(II) iodide

Nickel(II) iodide
IUPAC name Nickel(II) iodide
Other names Nickelous iodide
Identifiers
CAS number	13462-90-3
PubChem	26038
Properties
Molecular formula	I2Ni
Molar mass	312.5 g mol−1
Appearance	black solid, hydrate is green
Density	5.38 g/cm3
Melting point	780 °C, 1053 K, 1436 °F
Boiling point	797 °C, 1070 K, 1467 °F
Solubility in water	good
Solubility	alcohols
Hazards
NFPA 704	0 2 0
Related compounds
Other anions	nickel(II) chloride, nickel(II) bromide, nickel(II) fluoride
Other cations	cobalt iodide, copper iodide,
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
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.^[1] 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.^[2]

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.^[3] It is also has niche uses as a reagent in organic synthesis, especially in conjunction with samarium(II) iodide.^[4]

References

1. ^ Lide, D. R., ed (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5. 
2. ^ Laird G. L. Ward, "Anhydrous Nickel (II) Halides and their Tetrakis(Ethanol) and 1,2-Dimethoxyethane Complexes" Inorganic Syntheses, 1972, Volume 13, Pages: 154–164, 2007. doi:10.1002/9780470132449.ch30
3. ^ W. Bertleff, M. Roeper, X. Sava, “Carbonylation” in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH: Weinheim, 2003. DOI: 10.1002/14356007.a05 217.
4. ^ Shinichi Saito, Nickel(II) Iodide" in Encyclopedia of Reagents for Organic Synthesis, John Wiley & Sons, 2008. DOI: 10.1002/047084289X.rn00843. Article Online Posting Date: March 14, 2008.