Cerium(III) iodide

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Cerium(III) iodide
IUPAC name
Other names
Cerous triiodide, Cerium triiodide
3D model (JSmol)
ECHA InfoCard 100.029.299 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 232-228-3
PubChem CID
  • InChI=1S/Ce.3HI/h;3*1H/q+3;;;/p-3
  • I[Ce](I)I
Molar mass 520.829 g·mol−1
Appearanceyellow solid [1] [2]
Melting point 766 °C, [1] 752 °C [2]
soluble [2]
Solubility in acetone soluble [2]
Structure [1] [3] [4]
8-coordinate bicapped trigonal prismatic
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

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



Cerium metal reacts with iodine when heated to form cerium(III) iodide: [2]

2 Ce + 3 I2 → 2 CeI3

It is also formed when cerium reacts with mercury(II) iodide at high temperatures: [2]

2 Ce + 3 HgI2 → 2 CeI3 + 3 Hg


Cerium(III) iodide adopts the plutonium(III) bromide crystal structure. [3] [4] It contains 8-coordinate bicapped trigonal prismatic Ce3+ ions. [1]


Cerium(III) iodide is used as a pharmaceutical intermediate [5] and as a starting material for organocerium compounds. [2]

Related Research Articles

Cerium(III) chloride Chemical compound

Cerium(III) chloride (CeCl3), also known as cerous chloride or cerium trichloride, is a compound of cerium and chlorine. It is a white hygroscopic salt; it rapidly absorbs water on exposure to moist air to form a hydrate, which appears to be of variable composition, though the heptahydrate CeCl3·7H2O is known. It is highly soluble in water, and (when anhydrous) it is soluble in ethanol and acetone.

Triiodide Ion

In chemistry, triiodide usually refers to the triiodide ion, I
. This anion, one of the polyhalogen ions, is composed of three iodine atoms. It is formed by combining aqueous solutions of iodide salts and iodine. Some salts of the anion have been isolated, including thallium(I) triiodide (Tl+[I3]) and ammonium triiodide ([NH4]+[I3]). Triiodide is observed to be a red colour in solution.

Aluminium iodide 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.

Thallium triiodide Chemical compound

Thallium triiodide is a chemical compound of thallium and iodine with formula TlI3. Unlike the other thallium trihalides, which contain thallium(III), TlI3 is a thallium(I) salt and contains the triiodide ion, I

Bismuth(III) iodide Chemical compound

Bismuth(III) iodide is the inorganic compound with the formula BiI3. This gray-black salt is the product of the reaction of bismuth and iodine, which once was of interest in qualitative inorganic analysis.

Cerium Chemical element, symbol Ce and atomic number 58

Cerium is a chemical element with the symbol Ce and atomic number 58. Cerium is a soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the +3 oxidation state characteristic of the series, it also has a stable +4 state that does not oxidize water. It is also considered one of the rare-earth elements. Cerium has no known biological role in humans but is not particularly toxic, except with intense or continued exposure.

Californium compounds

Few compounds of californium have been made and studied. The only californium ion that is stable in aqueous solutions is the californium(III) cation. The other two oxidation states are IV (strong oxidizing agents) and II (strong reducing agents). The element forms a water-soluble chloride, nitrate, perchlorate, and sulfate and is precipitated as a fluoride, oxalate or hydroxide. If problems of availability of the element could be overcome, then CfBr2 and CfI2 would likely be stable.

Molybdenum(III) iodide Chemical compound

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

Yttrium iodide is a binary inorganic compound, a salt of yttrium and hydroiodic acid with the formula YI
. The compound forms colorless crystals, soluble in water.

Neodymium(II) iodide Chemical compound

Neodymium(II) iodide or neodymium diiodide is an inorganic salt of iodine and neodymium the formula NdI2. Neodymium uses the +2 oxidation state in the compound.

Praseodymium(III) iodide 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.

Praseodymium diiodide Chemical compound

Praseodymium diiodide is a chemical compound with the empirical formula of PrI2, consisting of praseodymium and iodine. It is an electride, with the ionic formula of Pr3+(I)2e, and therefore not a true praseodymium(II) compound.

Zirconium(III) iodide Chemical compound

Zirconium(III) iodide is an inorganic compound with the formula ZrI3.

Lanthanum(III) iodide Chemical compound

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

Europium(III) iodide is an inorganic compound containing europium and iodine with the chemical formula EuI3.

Lutetium(III) iodide Chemical compound

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

Gadolinium(III) iodide Chemical compound

Gadolinium(III) iodide is an iodide of gadolinium, with the chemical formula of GdI3. It is a yellow, highly hygroscopic solid with a bismuth(III) iodide-type crystal structure. In air, it quickly absorbs moisture and forms hydrates. The corresponding oxide iodide is also readily formed at elevated temperature.

Thulium(III) iodide Chemical compound

Thulium(III) iodide is an iodide of thulium, with the chemical formula of TmI3. Thulium(III) iodide is used as a component of metal halide lamps.

Cerium diiodide Chemical compound

Cerium diiodide is an iodide of cerium, with the chemical formula of CeI2.


  1. 1 2 3 4 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 1240–1241. ISBN   978-0-08-037941-8.
  2. 1 2 3 4 5 6 7 Imamoto, Tsuneo (15 April 2001). "Cerium(III) Iodide". Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons, Ltd. ISBN   9780471936237.
  3. 1 2 Wells, A. F. (1984). Structural Inorganic Chemistry (5th ed.). Oxford University Press. p. 421. ISBN   978-0-19-965763-6.
  4. 1 2 Asprey, L. B.; Keenan, T. K.; Kruse, F. H. (1964). "Preparation and Crystal Data for Lanthanide and Actinide Triiodides". Inorg. Chem. 3 (8): 1137–1141. doi:10.1021/ic50018a015.
  5. "7790-87-6 - Cerium(III) iodide, ultra dry, 99.9% (REO) - Cerium triiodide - 13641 - Alfa Aesar". alfa.com. Retrieved 2017-09-19.