Chromium(III) iodide

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Chromium(III) iodide
IUPAC name
Chromium(III) iodide
Other names
Chromium triiodide, chromic iodide
3D model (JSmol)
ECHA InfoCard 100.033.614 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 236-991-3
PubChem CID
  • InChI=1S/Cr.3HI/h;3*1H/q+3;;;/p-3
  • InChI=1/Cr.3HI/h;3*1H/q+3;;;/p-3/rCrI3/c2-1(3)4
  • [Cr](I)(I)I
Molar mass 432.710 g/mol
Appearanceblack solid
Density 5.32 g/cm3 [1]
Melting point >600 °C (1,112 °F; 873 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

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. [2]

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. [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 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. [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 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. [2]

Chromium triiodide can also be prepared as nanoplatelets from the alkoxide Cr(OCMetBu2)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]

Related Research Articles

<span class="mw-page-title-main">Iodine</span> Chemical element, symbol I and atomic number 53

Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at 114 °C (237 °F), and boils to a violet gas at 184 °C (363 °F). The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek Ιώδης 'violet-coloured'.

<span class="mw-page-title-main">Chromium(III) chloride</span> Chemical compound

Chromium(III) chloride (also called chromic chloride) describes any of several chemical compounds with the formula CrCl3 · xH2O, where x can be 0, 5, and 6. The anhydrous compound with the formula CrCl3 is a violet solid. The most common form of the trichloride is the dark green hexahydrate, CrCl3 · 6 H2O. Chromium chlorides find use as catalysts and as precursors to dyes for wool.

<span class="mw-page-title-main">Sodium iodide</span> Chemical compound

Sodium iodide (chemical formula NaI) is an ionic compound formed from the chemical reaction of sodium metal and iodine. Under standard conditions, it is a white, water-soluble solid comprising a 1:1 mix of sodium cations (Na+) and iodide anions (I) in a crystal lattice. It is used mainly as a nutritional supplement and in organic chemistry. It is produced industrially as the salt formed when acidic iodides react with sodium hydroxide. It is a chaotropic salt.

<span class="mw-page-title-main">Chromium(II) chloride</span> Chemical compound

Chromium(II) chloride describes inorganic compounds with the formula CrCl2(H2O)n. The anhydrous solid is white when pure, however commercial samples are often grey or green; it is hygroscopic and readily dissolves in water to give bright blue air-sensitive solutions of the tetrahydrate Cr(H2O)4Cl2. Chromium(II) chloride has no commercial uses but is used on a laboratory-scale for the synthesis of other chromium complexes.

<span class="mw-page-title-main">Titanium tetraiodide</span> Chemical compound

Titanium tetraiodide is an inorganic compound with the formula TiI4. It is a black volatile solid, first reported by Rudolph Weber in 1863. It is an intermediate in the van Arkel–de Boer process for the purification of titanium.

<span class="mw-page-title-main">Aluminium iodide</span> Chemical compound

Aluminium iodide is a chemical compound containing aluminium and iodine. Invariably, the name refers to a compound of the composition AlI
, formed by the reaction of aluminium and iodine or the action of HI on Al metal. The hexahydrate is obtained from a reaction between metallic aluminum or aluminum hydroxide with hydrogen iodide or hydroiodic acid. Like the related chloride and bromide, AlI
is a strong Lewis acid and will absorb water from the atmosphere. It is employed as a reagent for the scission of certain kinds of C-O and N-O bonds. It cleaves aryl ethers and deoxygenates epoxides.

Terbium(III) iodide (TbI3) is an inorganic chemical compound.

The polyiodides are a class of polyhalogen anions composed entirely of iodine atoms. The most common and simplest member is the triiodide ion, I
. Other known larger polyiodides include [I4]2−, [I5], [I6]2−, [I7], [I8]2−, [I9], [I10]2−, [I10]4−, [I11]3−, [I12]2−, [I13]3−, [I14]4-, [I16]2−, [I22]4−, [I26]3−, [I26]4−, [I28]4− and [I29]3−. All these can be considered as formed from the interaction of the I, I2, and I
building blocks.

Vanadium(III) iodide is the inorganic compound with the formula VI3. This paramagnetic solid is generated by the reaction of vanadium powder with iodine at around 500 °C. The black hygroscopic crystals dissolve in water to give green solutions, characteristic of V(III) ions.

<span class="mw-page-title-main">Uranium(IV) iodide</span> Chemical compound

Uranium(IV) iodide, also known as uranium tetraiodide, is an inorganic chemical compound. It is a salt of uranium in oxidation state +4 and iodine.

<span class="mw-page-title-main">Half sandwich compound</span> Class of coordination compounds

Half sandwich compounds, also known as piano stool complexes, are organometallic complexes that feature a cyclic polyhapto ligand bound to an MLn center, where L is a unidentate ligand. Thousands of such complexes are known. Well-known examples include cyclobutadieneiron tricarbonyl and (C5H5)TiCl3. Commercially useful examples include (C5H5)Co(CO)2, which is used in the synthesis of substituted pyridines, and methylcyclopentadienyl manganese tricarbonyl, an antiknock agent in petrol.

<span class="mw-page-title-main">Molybdenum(III) iodide</span> Chemical compound

Molybdenum(III) iodide is the inorganic compound with the formula MoI3.

Cerium(III) iodide (CeI3) is the compound formed by cerium(III) cations and iodide anions.

Chromium telluride (Cr2Te3) is an inorganic chemical compound. It is composed of the chromium(III) cation and the telluride anion. It has a shadowy gray color, and has a hexagonal crystal structure.

Magnetic 2D materials or magnetic van der Waals materials are two-dimensional materials that display ordered magnetic properties such as antiferromagnetism or ferromagnetism. After the discovery of graphene in 2004, the family of 2D materials has grown rapidly. There have since been reports of several related materials, all except for magnetic materials. But since 2016 there have been numerous reports of 2D magnetic materials that can be exfoliated with ease just like graphene.

Neodymium(III) iodide is an inorganic salt of iodine and neodymium the formula NdI3. Neodymium uses the +3 oxidation state in the compound. The anydrous compound is a green powdery solid at room temperature.

<span class="mw-page-title-main">Praseodymium(III) iodide</span> Chemical compound

Praseodymium(III) iodide is an inorganic salt, consisting of the rare-earth metal praseodymium with hydrogen iodide with the chemical formula PrI3, with green crystals. It is soluble in water.

<span class="mw-page-title-main">Lanthanum(III) iodide</span> Chemical compound

Lanthanum(III) iodide is an inorganic compound containing lanthanum and iodine with the chemical formula LaI

<span class="mw-page-title-main">Lutetium(III) iodide</span> Chemical compound

Lutetium(III) iodide or lutetium iodide is an inorganic compound consisting of iodine and lutetium, with the chemical formula of LuI3.

<span class="mw-page-title-main">Holmium(III) iodide</span> Chemical compound

Holmium(III) iodide is an iodide of holmium, with the chemical formula of HoI3. It is used as a component of metal halide lamps.


  1. 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.
  2. 1 2 3 Gregory, N. W.; Handy, L. L. (1957). "Chromium(III) Iodide". Inorg. Synth. 5: 128–130. doi:10.1002/9780470132364.ch34.
  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; 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 . doi:10.1021/acs.nanolett.0c00102. ISSN   1530-6984.
  5. 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.