zirconium(III) iodide
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| ImageFile1 = Zirconium(III)-iodide-xtal-chain-section-3D-bs-17.png
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| ImageName1 = Ball-and-stick model of a polymer chain of face-sharing octahedra in the crystal structure of zirconium(III) iodide
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| ImageFile2 = Zirconium(III)-iodide-xtal-packing-b-3x3x3-3D-bs-17.png
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| ImageName2 = Ball-and-stick model of the packing of polymer chains in the crystal structure of zirconium(III) iodide
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| Name = Zirconium(III) iodide
| IUPACName = Zirconium triiodide
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo = 13779-87-8
| CASNo_Ref = {{cascite|correct|CAS}}
| SMILES = [Zr+3].[I-].[I-].[I-]
| PubChem = 157424840
| ChemSpiderID_Ref =
| ChemSpiderID =
| StdInChI=1S/3HI.Zr/h3*1H;/q;;;+3/p-3
| StdInChIKey = BPVKTQRLRAVYEX-UHFFFAOYSA-K
}}
|Section2={{Chembox Properties
| Zr=1 | I=3
| Appearance = dark blue crystals{{ cite book | title = CRC Handbook of Chemistry and Physics | edition = 94th | publisher = CRC Press | year = 2013 | editor = William M. Haynes | page = 4-101 | isbn = 978-1466571143 }}
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| MeltingPtC = 727
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|Section3={{Chembox Structure
| CrystalStruct = Orthorhombic
| SpaceGroup = Pmmn, No. 59
| PointGroup =
| LattConst_a = 12.594 Å
| LattConst_b = 6.679 Å
| LattConst_c = 7.292 Å
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|Section4={{Chembox Thermochemistry
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|Section7={{Chembox Hazards
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|Section8={{Chembox Related
| OtherCompounds = Zirconium(IV) iodide
| OtherAnions = Zirconium(III) chloride
Zirconium(III) bromide
| OtherCations = Titanium(III) iodide
Hafnium(III) iodide
}}
}}
Zirconium(III) iodide is an inorganic compound with the formula ZrI3.
Preparation
Like other group 4 trihalides, zirconium(III) iodide can be prepared from zirconium(IV) iodide by high-temperature reduction with zirconium metal, although incomplete reaction and contamination of the product with excess metal often occurs.{{Greenwood&Earnshaw2nd|page=965}}
:3 ZrI4 + Zr → 4 ZrI3
An alternative is to crystallise zirconium(III) iodide from a solution of zirconium(III) in aluminium triiodide. The solution is prepared by reducing a eutectic solution of ZrI4 in liquid AlI3 at a temperature of 280–300 °C with metallic zirconium or aluminium.{{ cite journal | title = Synthesis of crystalline zirconium trihalides by reduction of tetrahalides in molten aluminum halides. Nonreduction of hafnium | first1 = E. M. | last1 = Larsen | first2 = James W. | last2 = Moyer | first3 = Francisco | last3 = Gil-Arnao | first4 = Michael J. | last4 = Camp | journal = Inorg. Chem. | year = 1974 | volume = 13 | issue = 3 | pages = 574–581 | doi = 10.1021/ic50133a015 }}{{ cite journal | title = Single-crystal structures of ZrX3 (X = Cl−, Br−, I−) and ZrI3.40 synthesized in low-temperature aluminum halide melts | first1 = Edwin M. | last1 = Larsen | first2 = Julie S. | last2 = Wrazel | first3 = Laurence G. | last3 = Hoard | journal = Inorg. Chem. | year = 1982 | volume = 21 | issue = 7 | pages = 2619–2624 | doi = 10.1021/ic00137a018 }}
Structure and bonding
Zirconium(III) iodide has a lower magnetic moment than is expected for the d1 metal ion Zr3+, indicating non-negligible Zr–Zr bonding.
The crystal structure of zirconium(III) iodide is based on hexagonal close packing of iodide ions with one third of the octahedral interstices occupied by Zr3+ ions. The structure consists of parallel chains of face-sharing {ZrI6} octahedra{{ cite book | first1 = A. F. | last1 = Wells | title = Structural Inorganic Chemistry | edition = 5th | year = 1984 | publisher = Oxford University Press | isbn = 978-0-19-965763-6 | pages = 418–419 }} with unequally spaced metal atoms. The Zr–Zr separation alternates between 3.17 Å and 3.51 Å.{{ cite journal | title = Revision of the structure of zirconium triiodide. The presence of metal dimers | first1 = Abdessadek | last1 = Lachgar | first2 = Douglas S. | last2 = Dudis | first3 = John D. | last3 = Corbett | journal = Inorg. Chem. | year = 1990 | volume = 29 | issue = 12 | pages = 2242–2246 | doi = 10.1021/ic00337a013 }}
ZrCl3, ZrBr3 and ZrI3 adopt structures very similar to the β-TiCl3 structure. In all three ZrX3 there is some elongation of the octahedra along the metal-metal axis, partly due to metal-metal repulsion, but the elongation is most pronounced in the chloride, moderate in the bromide and negligible in the iodide.
References
{{reflist}}
{{Zirconium compounds}}
{{Iodides}}
{{DEFAULTSORT:Zirconium(Iii) Iodide}}