Chemistry:Chromium(III) iodide

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Chromium(III) iodide
Chromium(III)-iodide-xtal-viewed-down-c-axis-3D-bs-17.png
Names
IUPAC name
Chromium(III) iodide
Other names
Chromium triiodide, chromic iodide
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 236-991-3
Properties
CrI3
Molar mass 432.7095 g·mol−1
Appearance black solid
Density 5.32 g/cm3[1]
Melting point > 600 °C (1,112 °F; 873 K)
Soluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Chromium(III) iodide, also known as chromium triiodide, is an inorganic compound with the formula CrI
3
. It is a black solid that is used to prepare other chromium iodides.[2]

Like the isomorphous chromium(III) chloride (CrCl
3
), chromium(III) iodide exhibits a cubic-closest packing arrangement in a double-layer crystal lattice. In this structure, chromium exhibits octahedral coordination geometry.[3]

Preparation and properties

Chromium triiodide is prepared by the direct reaction of chromium metal with an excess of iodine. The reaction is conducted at 500 °C:

2 Cr + 3 I
2
→ 2 CrI
3

To obtain high purity samples, the product is thermally decomposed at 700 °C to sublime out chromium(II) iodide. The diiodide is then reiodinated.[2]

Chromium triiodide is stable in contact with oxygen and moisture, but at temperatures approaching 200 °C it reacts with oxygen and releases iodine. Like CrCl
3
, the triiodide exhibits slow solubility in water owing to the kinetic inertness of Cr(III). Addition of small amounts of chromous iodide accelerates the dissolving process.[2]

Chromium triiodide can also be prepared as nanoplatelets[clarification needed] from the alkoxide Cr(OC(CH
3
)(C(CH
3
)
3
)
2
)
3
.[4]

Chromium triiodide was one of the first materials which was discovered to be a magnetic two-dimensional material that has great potentials for spintronics devices.[5]

References

  1. Perry, Dale L. (2011). Handbook of Inorganic Compounds, Second Edition. Boca Raton, Florida: CRC Press. p. 123. ISBN 978-1-43981462-8. https://books.google.com/books?id=SFD30BvPBhoC. Retrieved 2014-01-10. 
  2. 2.0 2.1 2.2 Gregory, N. W.; Handy, L. L. (1957). "Chromium (III) Iodide". Inorganic Syntheses. 5. 128–130. doi:10.1002/9780470132364.ch34. ISBN 9780470132364. 
  3. Gregory, N. W.; Handy, L. L. (1952). "Structural Properties of Chromium(III) Iodide and Some Chromium(III) Mixed Halides". J. Am. Chem. Soc. 74 (4): 891–893. doi:10.1021/ja01124a009. 
  4. De Siena, Michael C.; Creutz, Sidney E.; Regan, Annie; Malinowski, Paul; Jiang, Qianni; Kluherz, Kyle T.; Zhu, Guomin; Lin, Zhong et al. (2020-03-11). "Two-Dimensional van der Waals Nanoplatelets with Robust Ferromagnetism". Nano Letters 20 (3): 2100–2106. doi:10.1021/acs.nanolett.0c00102. ISSN 1530-6984. PMID 32031382. https://doi.org/10.1021/acs.nanolett.0c00102. 
  5. Huang, B. (2017). "Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit". Nature 546 (7657): 270–273. doi:10.1038/nature22391. PMID 28593970. Bibcode2017Natur.546..270H. 
HI He
LiI BeI2 BI3 CI4 NI3 I2O4,
I2O5,
I4O9
IF,
IF3,
IF5,
IF7
Ne
NaI MgI2 AlI3 SiI4 PI3,
P2I4
S ICl,
ICl3
Ar
KI CaI2 Sc TiI4 VI3 CrI3 MnI2 FeI2 CoI2 NiI2 CuI ZnI2 Ga2I6 GeI2,
GeI4
AsI3 Se IBr Kr
RbI SrI2 YI3 ZrI4 NbI5 Mo Tc Ru Rh Pd AgI CdI2 InI3 SnI4,
SnI2
SbI3 TeI4 I Xe
CsI BaI2   HfI4 TaI5 W Re Os Ir Pt AuI Hg2I2,
HgI2
TlI PbI2 BiI3 Po AtI Rn
Fr RaI2   Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
La Ce Pr Nd Pm SmI2 Eu Gd TbI3 Dy Ho Er Tm Yb Lu
Ac ThI4 Pa UI3,
UI4
Np Pu Am Cm Bk Cf EsI3 Fm Md No Lr