Nickel(II) iodide

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Nickel(II) iodide
Nickel(II) iodide hexahydrate, NiI2•6H2O
Nickel(II) iodide
Identifiers
CAS number 13462-90-3
PubChem 26038
Jmol-3D images Image 1
Properties
Molecular 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 (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
Hazards
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Related compounds
Other anions nickel(II) chloride, nickel(II) bromide, nickel(II) fluoride
Other cations cobalt iodide, copper iodide,
Except where noted otherwise, 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.[1] This blue-green colour is typical of hydrated nickel(II) compounds. Nickel iodides find some applications in homogeneous catalysis.

Structure and synthesis[edit]

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[edit]

  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.