Zirconium(III) iodide
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| Names | |
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| IUPAC name
Zirconium triiodide
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| Identifiers | |
3D model (JSmol)
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PubChem CID
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| Properties | |
| I3Zr | |
| Molar mass | 471.937 g·mol−1 |
| Appearance | dark blue crystals[1] |
| Melting point | 727 °C (1,341 °F; 1,000 K) |
| Structure | |
| Orthorhombic | |
| Pmmn, No. 59 | |
a = 12.594 Å, b = 6.679 Å, c = 7.292 Å
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| Related compounds | |
Other anions
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Zirconium(III) chloride Zirconium(III) bromide |
Other cations
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Titanium(III) iodide Hafnium(III) iodide |
Related compounds
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Zirconium(IV) iodide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Zirconium(III) iodide is an inorganic compound with the formula ZrI3.
Preparation
[edit]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.[2]
- 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.[3][4]
Structure and bonding
[edit]Zirconium(III) iodide has a lower magnetic moment than is expected for the d1 metal ion Zr3+, indicating non-negligible Zr–Zr bonding.[2]
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.[2] The structure consists of parallel chains of face-sharing {ZrI6} octahedra[5] with unequally spaced metal atoms. The Zr–Zr separation alternates between 3.17 Å and 3.51 Å.[6]
ZrCl3, ZrBr3 and ZrI3 adopt structures very similar to the β-TiCl3 structure.[2] In all three ZrX3 there is some elongation of the octahedra along the metal-metal axis, partly due to metal-metal repulsion,[4] but the elongation is most pronounced in the chloride, moderate in the bromide and negligible in the iodide.[4]
References
[edit]- ^ William M. Haynes, ed. (2013). CRC Handbook of Chemistry and Physics (94th ed.). CRC Press. p. 4-101. ISBN 978-1466571143.
- ^ a b c d Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 965. ISBN 978-0-08-037941-8.
- ^ Larsen, E. M.; Moyer, James W.; Gil-Arnao, Francisco; Camp, Michael J. (1974). "Synthesis of crystalline zirconium trihalides by reduction of tetrahalides in molten aluminum halides. Nonreduction of hafnium". Inorg. Chem. 13 (3): 574–581. doi:10.1021/ic50133a015.
- ^ a b c Larsen, Edwin M.; Wrazel, Julie S.; Hoard, Laurence G. (1982). "Single-crystal structures of ZrX3 (X = Cl−, Br−, I−) and ZrI3.40 synthesized in low-temperature aluminum halide melts". Inorg. Chem. 21 (7): 2619–2624. doi:10.1021/ic00137a018.
- ^ Wells, A. F. (1984). Structural Inorganic Chemistry (5th ed.). Oxford University Press. pp. 418–419. ISBN 978-0-19-965763-6.
- ^ Lachgar, Abdessadek; Dudis, Douglas S.; Corbett, John D. (1990). "Revision of the structure of zirconium triiodide. The presence of metal dimers". Inorg. Chem. 29 (12): 2242–2246. doi:10.1021/ic00337a013.