Aluminium iodide is a chemical compound containing aluminium and iodine. Invariably, the name refers to a compound of the composition AlI3, 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, AlI3 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.
Structure
Solid AlI3 is dimeric, consisting of Al2I6, similar to that of AlBr3.3 The structure of monomeric and dimeric forms have been characterized in the gas phase.4 The monomer, AlI3, is trigonal planar with a bond length of 2.448(6) Å, and the bridged dimer, Al2I6, at 430 K is a similar to Al2Cl6 and Al2Br6 with Al−I bond lengths of 2.456(6) Å (terminal) and 2.670(8) Å (bridging). The dimer is described as floppy with an equilibrium geometry of D2h.
Aluminium(I) iodide
Main article: Aluminium monoiodide
The name "aluminium iodide" is widely assumed to describe the triiodide or its dimer. In fact, a monoiodide also enjoys a role in the Al–I system, although the compound AlI is unstable at room temperature relative to the triiodide:5
3 AlI → AlI3 + 2 AlAn illustrative derivative of aluminium monoiodide is the cyclic adduct formed with triethylamine, Al4I4(NEt3)4.
External links
- Media related to Aluminium iodide at Wikimedia Commons
References
Watt, George W; Hall, James L; Taylor, William Lloyd; Kleinberg, Jacob (1953). "Aluminum Iodide". Inorganic Syntheses. Vol. 4. pp. 117–119. doi:10.1002/9780470132357.ch39. ISBN 9780470132357. {{cite book}}: ISBN / Date incompatibility (help) 9780470132357 ↩
Gugelchuk, M. (2004). "Aluminum Iodide". In L. Paquette (ed.). Encyclopedia of Reagents for Organic Synthesis. New York: J. Wiley & Sons. doi:10.1002/047084289X.ra083. ISBN 0471936235. 0471936235 ↩
Troyanov, Sergey I.; Krahl, Thoralf; Kemnitz, Erhard (2004). "Crystal structures of GaX3(X= Cl, Br, I) and AlI3". Zeitschrift für Kristallographie. 219 (2–2004): 88–92. doi:10.1524/zkri.219.2.88.26320. S2CID 101603507. /wiki/Doi_(identifier) ↩
Hargittai, Magdolna; Réffy, Balázs; Kolonits, Mária (2006). "An Intricate Molecule: Aluminum Triiodide. Molecular Structure of AlI3and Al2I6 from Electron Diffraction and Computation". The Journal of Physical Chemistry A. 110 (10): 3770–3777. doi:10.1021/jp056498e. PMID 16526661. /wiki/Doi_(identifier) ↩
Dohmeier, C.; Loos, D.; Schnöckel, H. (1996). "Aluminum(I) and Gallium(I) Compounds: Syntheses, Structures, and Reactions". Angewandte Chemie International Edition. 35 (2): 129–149. doi:10.1002/anie.199601291. /wiki/Doi_(identifier) ↩