| Names | |
|---|---|
| IUPAC name Iron(III) iodide | |
| Other names Ferric iodide | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider | |
| |
| |
| Properties | |
| FeI3 | |
| Molar mass | 436.56 g/mol |
| Appearance | Black solid |
| decomposes | |
| Solubility | sparingly soluble indichloromethane |
| Related compounds | |
Otheranions | FeF3,FeCl3,FeBr3 |
Othercations | ScI3,TiI3,VI3,MoI3,WI3,RhI3,BiI3 |
Related compounds | FeI2 |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Iron(III) iodide is aninorganic compound with thechemical formula FeI3. It is athermodynamically unstable compound that is difficult to prepare. Nevertheless, iron(III) iodide has been synthesised in small quantities in the absence of air and water.[1]
Iron(III) and iodide tend to undergo aredox reaction[1] in which Fe3+ is reduced to Fe2+ and I− is oxidised to I2. This reaction can be avoided and iron(III) iodide can be synthesised by aphotochemical reaction.Iron pentacarbonyl reacts with excessiodine in hexane under argon, releasingcarbon monoxide and forming the complexdiiodotetracarbonyliron(II), Fe(CO)4I2, as a light red solution.[1][2]
This complex then undergoes oxidative photodecarbonylation at −20 °C in the presence of further iodine andactinic light. A black film of FeI3 is deposited as further carbon monoxide is evolved.[1][2]
Iron(III) iodide is prone tolight-induced decomposition toiron(II) iodide and iodine.[2][3][4]
Donor solvents such astetrahydrofuran,acetonitrile,pyridine andwater also promote this reaction: iron(III) iodide is extremelyhygroscopic. It is sparingly soluble indichloromethane. It reacts with iodide to form the tetraiodoferrate(III) ion.[2]
Iron(III) iodide undergoesligand exchange ormetathesis with certainalkyl chlorides toreversibly formiron(III) chloride and the correspondingalkyl iodides.[2]
Adducts of FeI3 are well known. An orange complex can be prepared from FeI2 and I2 in the presence ofthiourea.[5][6] Iron powder reacts with iodine-containing proligands to also give adducts of ferric iodide.[7]
