Iron(II) iodide

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Iron(II) iodide
Names
IUPAC name
Iron(II) iodide
Other names
Ferrous iodide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.119 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 232-031-2
PubChem CID
UNII
  • InChI=1S/Fe.2HI/h;2*1H/q+2;;/p-2
    Key: BQZGVMWPHXIKEQ-UHFFFAOYSA-L
  • InChI=1/Fe.2HI/h;2*1H/q+2;;/p-2
    Key: BQZGVMWPHXIKEQ-NUQVWONBAN
  • [Fe+2].[I-].[I-]
Properties
FeI2
Molar mass 309.65 g/mol
AppearanceWhite to off-white or grey [1] powder
Density 5.315 g/cm3
Melting point 587 °C (1,089 °F; 860 K)
Boiling point 827 °C (1,521 °F; 1,100 K)
soluble
+13,600·10−6 cm3/mol
Related compounds
Other anions
Iron(II) fluoride
Iron(II) chloride
Iron(II) bromide
Other cations
Manganese(II) iodide
Cobalt(II) iodide
Related Iron iodides
Iron(III) iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Iron(II) iodide is an inorganic compound with the chemical formula FeI2. [1] [2] It is used as a catalyst in organic reactions.

Contents

Preparation

Iron(II) iodide can be synthesised by the reaction of iron with iodine at 500 °C: [1] [3]

Fe + I2 → FeI2

This is in contrast to the other iron(II) halides, which are best prepared by reaction of heated iron with the appropriate hydrohalic acid.

Fe + 2 HX → FeX2 + H2

Alternatively, the synthesis can be carried out by treating freshly reduced iron with concentrated hydriodic acid under a nitrogen atmosphere in methanol. The initially obtained hexamethanol solvate is then thermally decomposed to anhydrous iodide:

Fe + 2 HI + 6 MeOH → FeI2·6MeOH + H2
FeI2·6 MeOH → FeI2 + 6 MeOH

Extremely finely divided iron(II) iodide is obtained by thermal decomposition of tetracarbonyldiiodidoiron(II) (Fe(CO)4I2). [3]

In contrast to the ferrous fluoride, chloride and bromide, which form known hydrates, the diiodide is speculated to form a stable tetrahydrate but it not been characterized directly. [4]

Chemical properties

Iron(II) iodide is a hygroscopic red-violet to black solid that is soluble in water, ethanol and diethyl ether. Rapid oxidation occurs in solution and in moist air. [5] It turns whitish when exposed to air. The solution in water is colorless.

Dissolving iron metal in hydroiodic acid is another route to aqueous solutions of iron(II) iodide. Crystalline hydrates precipitate from these solutions. [1] [ clarification needed ]

Physical properties

Iron(II) iodide adopts the same crystal structure as cadmium iodide (CdI2). [1] It crystallizes in the trigonal crystal system of the cadmium hydroxide type with the space group P3m1 (space group no. 164) and lattice constants a = 404 pm, c = 675 pm. [3] [6]

Applications

Iron(II) iodide is used as an ingredient in homeopathic medicines. In the field of application it is known as Ferrum jodatum. However, the attributed effect, particularly against glandular diseases, has not been scientifically confirmed.

It is also used for the production of alkali iodides. [6]

See also

Related Research Articles

Iron(II) chloride, also known as ferrous chloride, is the chemical compound of formula FeCl2. It is a paramagnetic solid with a high melting point. The compound is white, but typical samples are often off-white. FeCl2 crystallizes from water as the greenish tetrahydrate, which is the form that is most commonly encountered in commerce and the laboratory. There is also a dihydrate. The compound is highly soluble in water, giving pale green solutions.

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

Nickel(II) iodide is an inorganic compound with the formula NiI2. This paramagnetic black solid dissolves readily in water to give bluish-green solutions, from which crystallizes the aquo complex [Ni(H2O)6]I2 (image above). This bluish-green colour is typical of hydrated nickel(II) compounds. Nickel iodides find some applications in homogeneous catalysis.

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

Sodium formate, HCOONa, is the sodium salt of formic acid, HCOOH. It usually appears as a white deliquescent powder.

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

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

Tellurium tetraiodide (TeI4) is an inorganic chemical compound. It has a tetrameric structure which is different from the tetrameric solid forms of TeCl4 and TeBr4. In TeI4 the Te atoms are octahedrally coordinated and edges of the octahedra are shared.

Magnesium compounds are compounds formed by the element magnesium (Mg). These compounds are important to industry and biology, including magnesium carbonate, magnesium chloride, magnesium citrate, magnesium hydroxide, magnesium oxide, magnesium sulfate, and magnesium sulfate heptahydrate.

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

Rubidium iodide is a salt of rubidium and iodine, with the chemical formula RbI. It is a white solid with a melting point of 642 °C.

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

Cobalt(II) iodide or cobaltous iodide are the inorganic compounds with the formula CoI2 and the hexahydrate CoI2(H2O)6. These salts are the principal iodides of cobalt.

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

Holmium(III) chloride is the inorganic compound with the formula HoCl3. It is a common salt but is mainly used in research. It can be used to produce pure holmium. It exhibits the same color-changing behavior seen in holmium oxide, being a yellow in natural lighting and a bright pink color in fluorescent lighting.

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

Palladium(II) iodide is an inorganic compound of palladium and iodine. It is commercially available, though less common than palladium(II) chloride, the usual entry point to palladium chemistry. Three polymorphs are known.

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

Manganese(II) iodide is the chemical compound composed of manganese and iodide with the formula MnI2(H2O)n. The tetrahydrate is a pink solid while the anhydrous derivative is beige. Both forms feature octahedral Mn centers. Unlike MnCl2(H2O)4 and MnBr2(H2O)4 which are cis, MnI2(H2O)4 is trans.

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

Germanium(II) iodide is an iodide of germanium, with the chemical formula of GeI2.

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

Germanium(IV) iodide is an inorganic compound with the chemical formula GeI4.

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

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

Erbium(III) iodide is an iodide of lanthanide metal erbium. The compound is insoluble in water and is white to slightly pink in appearance.

Gadolinium(III) fluoride is an inorganic compound with a chemical formula GdF3.

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

Chromium(II) iodide is the inorganic compound with the formula CrI2. It is a red-brown 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.

<span class="mw-page-title-main">Europium compounds</span> Chemical compounds

Europium compounds are compounds formed by the lanthanide metal europium (Eu). In these compounds, europium generally exhibits the +3 oxidation state, such as EuCl3, Eu(NO3)3 and Eu(CH3COO)3. Compounds with europium in the +2 oxidation state are also known. The +2 ion of europium is the most stable divalent ion of lanthanide metals in aqueous solution. Many europium compounds fluoresce under ultraviolet light due to the excitation of electrons to higher energy levels. Lipophilic europium complexes often feature acetylacetonate-like ligands, e.g., Eufod.

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

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

Dysprosium(II) iodide is an iodide of dysprosium with the chemical formula DyI2.

References

  1. 1 2 3 4 5 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 1083–1084. ISBN   978-0-08-037941-8.
  2. ↑ University of Akron Chemical Database Archived 2012-12-12 at archive.today
  3. 1 2 3 Handbuch der präparativen anorganischen Chemie. 3 (3., umgearb. Aufl ed.). Stuttgart: Enke. 1981. ISBN   978-3-432-87823-2.
  4. ↑ Wren, J.C; Glowa, G.A; Merritt, J (1999). "Corrosion of stainless steel by gaseous I2". Journal of Nuclear Materials. 265 (1–2): 161–177. doi:10.1016/s0022-3115(98)00504-2. ISSN   0022-3115.
  5. ↑ Lautenschläger, Karl-Heinz; Schröter, Werner; Wanninger, Andrea (2007). Taschenbuch der Chemie (20., überarb. u. erw. Aufl., [Ausg. mit CD-ROM] ed.). Frankfurt am Main: Deutsch. ISBN   978-3-8171-1760-4.
  6. 1 2 Ans, Jan d'; Ans, Jan d' (1998). Elemente, anorganische Verbindungen und Materialien. Taschenbuch für Chemiker und Physiker / D'Ans (4., neubearb. u. rev. Aufl ed.). Ort nicht ermittelbar: Verlag nicht ermittelbar. ISBN   978-3-540-60035-0.
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