Chromium(III) iodide
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| Names | |
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| IUPAC name
Chromium(III) iodide
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| Other names
Chromium triiodide, chromic iodide
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| Identifiers | |
CAS Number
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3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.033.614 |
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PubChem CID
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CompTox Dashboard (EPA)
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InChI
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SMILES
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| Properties | |
Chemical formula
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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) |
Solubility in water
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Soluble |
| Hazards | |
| GHS labelling:[2] | |
Pictograms
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Signal word
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Danger |
Hazard statements
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H301, H314 |
Precautionary statements
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P260, P264, P264+P265, P270, P280, P301+P316, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P321, P330, P363, P405, P501 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
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Chromium(III) iodide, also known as chromium triiodide, is an inorganic compound with the formula CrI3. It is a black solid that is used to prepare other chromium iodides.[3]
Like the isomorphous chromium(III) chloride (CrCl3), chromium(III) iodide exhibits a cubic-closest packing arrangement in a double-layer crystal lattice. In this structure, chromium exhibits octahedral coordination geometry.[4]
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 I2 → 2 CrI3
To obtain high purity samples, the product is thermally decomposed at 700 °C to sublime out chromium(II) iodide. The diiodide is then reiodinated.[3]
Chromium triiodide is stable in contact with oxygen and moisture, but at temperatures approaching 200 °C it reacts with oxygen and releases iodine. Like CrCl3, 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.[3]
Chromium triiodide can also be prepared as colloidal nanoplatelets, a type of lateral nanostructure. The alkoxide Cr(OC(CH3)(C(CH3)3)2)3 is dissolved in toluene under an inert atmosphere, followed by the addition of trimethylsilyl iodide.[5] The mixture is sealed and immersed into a preheated oil bath at 135 °C, resulting in the formation of a black precipitate.[5]
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.[6]
References
- ^ Perry, Dale L. (2011). Handbook of Inorganic Compounds, Second Edition. Boca Raton, Florida: CRC Press. p. 123. ISBN 978-1-43981462-8. Retrieved 2014-01-10.
- ^ PubChem. "Chromium iodide (CrI3)". pubchem.ncbi.nlm.nih.gov. Retrieved 2026-02-08.
- ^ a b c Gregory, N. W.; Handy, L. L. (1957). "Chromium (III) Iodide". Inorganic Syntheses. Vol. 5. pp. 128–130. doi:10.1002/9780470132364.ch34.
{{cite book}}:|journal=ignored (help) - ^ 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.
- ^ a b De Siena, Michael C.; Creutz, Sidney E.; Regan, Annie; Malinowski, Paul; Jiang, Qianni; Kluherz, Kyle T.; Zhu, Guomin; Lin, Zhong; De Yoreo, James J.; Xu, Xiaodong; Chu, Jiun-Haw (2020-03-11). "Two-Dimensional van der Waals Nanoplatelets with Robust Ferromagnetism". Nano Letters. 20 (3): 2100–2106. arXiv:2001.04594. Bibcode:2020NanoL..20.2100D. doi:10.1021/acs.nanolett.0c00102. ISSN 1530-6984. PMID 32031382. S2CID 210473134.
- ^ Huang, B.; et al. (2017). "Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit". Nature. 546 (7657): 270–273. arXiv:1703.05892. Bibcode:2017Natur.546..270H. doi:10.1038/nature22391. PMID 28593970. S2CID 4456526.