Chromium(II) iodide
Names
Other names
chromous iodide
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/Cr.2HI/h;2*1H/q+2;;/p-2
    Key: BMSDTRMGXCBBBH-UHFFFAOYSA-L
  • [Cr+2].[I-].[I-]
Properties
CrI2
Molar mass 305.8050 g·mol−1
Appearance black deliquescent solid
Density 5.196 g/cm3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Chromium(II) iodide is the inorganic compound with the formula CrI2. It is a red-brown[1] or black solid. The compound is made by thermal decomposition of chromium(III) iodide. Like many metal diiodides, CrI2 adopts the "cadmium iodide structure" motif, i.e., it features sheets of octahedral Cr(II) centers interconnected by bridging iodide ligands. Reflecting the effects of its d4 configuration, chromium's coordination sphere is highly distorted.[1][2][3]

Treatment of chromium powder with concentrated hydroiodic acid gives a blue hydrated chromium(II) iodide, which can be converted to related acetonitrile complexes.[4]

Cr + n H2O + 2 HI → CrI2(H2O)n + H2

References

  1. ^ a b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 1019–1022. ISBN 978-0-08-037941-8.
  2. ^ Tracy, J. W.; Gregory, N. W.; Stewart, J. M.; Lingafelter, E. C. (1962). "The Crystal Structure of Chromium(II) Iodide". Acta Crystallographica. 15 (5): 460–463. doi:10.1107/S0365110X62001152.
  3. ^ Vest, Brian; Hermann, Andreas; Boyd, Peter D. W.; Schwerdtfeger, Peter (2010). "Nucleation of Antiferromagnetically Coupled Chromium Dihalides: From Small Clusters to the Solid State". Inorganic Chemistry. 49 (7): 3169–3182. doi:10.1021/ic901949a.
  4. ^ Holah, David G.; Fackler, John P. (1967). "Chromium(II) Salts and Complexes". Inorganic Syntheses: 26–35. doi:10.1002/9780470132418.ch4.
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