|Preferred IUPAC name
|UN number||UN 3260|
|Molar mass||407.69495 g/mol (anhydrous)
515.786 g/mol (hexahydrate)
but impure samples
are often brown
|Density||3.98 g/cm3 (anhydrous)
2.63 g/cm3 (hexahydrate)
|Melting point||189.4 °C (372.9 °F; 462.5 K) (anhydrous)
185 °C, decomposes (hexahydrate)
|Boiling point||360 °C (680 °F; 633 K) , sublimes|
|reacts violently (anhydrous)
|Solubility in alcohol, ether||soluble (hexahydrate)|
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
Aluminium iodide is any chemical compound containing only 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.
Solid AlI3 is dimeric, consisting of Al2I6, similar to that of AlBr3. The structure of monomeric and dimeric forms have been characterized in the gas phase. 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.
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
- 3 AlI → AlI3 + 2 Al
- G. W. Watt, J. L. Hall (1953). Inorganic Syntheses IV. pp. 117–119.
- M. Gugelchuk (2004). Aluminum Iodide, in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette). New York: J. Wiley & Sons. doi:10.1002/047084289X.ra083.
- 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.126.96.36.199320. ISSN 0044-2968.
- Hargittai, Magdolna; Réffy, Balázs; Kolonits, Mária (2006). "An Intricate Molecule: Aluminum Triiodide. Molecular Structure of AlI3and Al2I6from Electron Diffraction and Computation". The Journal of Physical Chemistry A 110 (10): 3770–3777. doi:10.1021/jp056498e. ISSN 1089-5639.
- Dohmeier, C.; Loos, D.; Schnöckel, H. (1996). "Aluminum(I) and Gallium(I) Compounds: Syntheses, Structures, and Reactions". Angewandte Chemie International Edition 35: 129–149. doi:10.1002/anie.199601291.