Aluminium iodide

Aluminium iodide is a chemical compound containing aluminium and iodine. Invariably, the name refers to a compound of the composition AlI
3
, formed by the reaction of aluminium and iodine[4] 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, AlI
3
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.[5]

Aluminium iodide
Names
Preferred IUPAC name
Aluminium iodine
Other names
Aluminium(III) iodide

Aluminum iodide
Aluminium triiodide

Aluminum triiodide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.140
EC Number
  • 232-054-8
UNII
UN number UN 3260
Properties
AlI3, AlI3·6H2O (hexahydrate)
Molar mass 407.695 g/mol (anhydrous)
515.786 g/mol (hexahydrate)[1]
Appearance white (anhydrous) or yellow powder (hexahydrate)[1]
Density 3.98 g/cm3 (anhydrous)[1] 2.63 g/cm3 (hexahydrate)[2]
Melting point 188.28 °C (370.90 °F; 461.43 K) (anhydrous)
185 °C, decomposes (hexahydrate)[1][2]
Boiling point 382 °C (720 °F; 655 K) anhydrous, sublimes[1]
very soluble, partial hydrolysis
Solubility in alcohol, ether soluble (hexahydrate)
Structure[3]
Monoclinic, mP16
P21/c, No. 14
a = 1.1958 nm, b = 0.6128 nm, c = 1.8307 nm
α = 90°, β = 90°, γ = 90°
8
Thermochemistry[1]
98.7 J/(mol·K)
195.9 J/(mol·K)
-302.9 kJ/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Structure

Solid AlI
3
is dimeric, consisting of Al
2
I
6
, similar to that of AlBr3.[3] The structure of monomeric and dimeric forms have been characterized in the gas phase.[6] The monomer, AlI
3
is trigonal planar with a bond length of 2.448(6) Å, and the bridged dimer, Al
2
I
6
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

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:[7]

3 AlIAlI
3
+ 2 Al

An illustrative derivative of aluminium monoiodide is the cyclic adduct formed with triethylamine, Al
4
I
4
(NEt
3
)
4
.

References

  1. Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 4.45. ISBN 1439855110.
  2. Perry, Dale L. (19 April 2016). Handbook of Inorganic Compounds, Second Edition. CRC Press. p. 8. ISBN 978-1-4398-1462-8.
  3. 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.
  4. Watt, George W; Hall, James L; Taylor, William Lloyd; Kleinberg, Jacob (1953). "Aluminum Iodide". Inorganic Syntheses. Inorganic Syntheses. 4. pp. 117–119. doi:10.1002/9780470132357.ch39. ISBN 9780470132357.
  5. 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.
  6. 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.
  7. 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.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.