Aluminum Chloride

Title: Aluminum Chloride
CAS Registry Number: 7446-70-0
Molecular Formula: AlCl3
Molecular Weight: 133.34
Percent Composition: Al 20.24%, Cl 79.77%
Literature References: Prepd from aluminum metal in a heated stream of HCl gas: Gattermann-Wieland, Praxis des Organischen Chemikers (de Gruyter, Berlin, 40th ed., 1961) p 295; H. J. Becher in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) p 812. Manufacture: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 72-75. Monograph: ACS Monograph Series no. 87, entitled "Anhydrous Aluminum Chloride in Organic Chemistry," C. A. Thomas, Ed. (Reinhold, New York, 1941).
Properties: White when pure; ordinarily gray or yellow to greenish. Fumes in air; strong odor of HCl; when heated in small quantities volatilizes without melting. Combines with water with explosive violence and liberation of much heat. Freely sol in many organic solvents, such as benzophenone, benzene nitrobenzene, carbon tetrachloride, chloroform. Keep tightly closed and protected from moisture. For physical properties see C. A. Thomas, loc. cit.
Derivative Type: Hexahydrate
CAS Registry Number: 7784-13-6
Trademarks: Anhydrol (Dermal); Driclor (Stiefel); Drysol (Person & Covey); Xerac (Person & Covey)
Properties: Colorless crystals, or white or slightly yellow deliquesc, cryst powder; odorless or slight HCl odor. One gram dissolves in 0.9 ml water, 4 ml alc; sol in ether, glycerol, propylene glycol. Keep well closed.
CAUTION: Anhydrous form is a strong irritant.
Use: The anhydrous form suitable as an acid catalyst, esp in Friedel-Crafts type reactions; in cracking of petroleum; in manuf rubbers, lubricants. The hexahydrate form used in preserving wood; disinfecting stables, slaughterhouses, etc.; in deodorants and antiperspirant preparations; refining crude oil; dyeing fabrics; manuf parchment paper.
Therap-Cat: The hexahydrate as anhidrotic.
Keywords: Astringent.
Aluminum Ethoxide Aluminum Fluoride Aluminum Hexafluorosilicate Aluminum Hexaurea Sulfate Triiodide Aluminum Hydride

Aluminium chloride
Aluminium chloride
Aluminium trichloride dimer
CAS number 7446-70-0 (anhydrous) YesY
10124-27-3 (hydrate),
7784-13-6 (hexahydrate)
PubChem 24012
ChemSpider 22445 YesY
ChEBI CHEBI:30114 YesY
RTECS number BD0530000
ATC code D10AX01
Jmol-3D images Image 1
Image 2
Molecular formula AlCl3
Molar mass 133.34 g/mol (anhydrous)
241.43 g/mol (hexahydrate)
Appearance white or pale yellow solid,
Density 2.48 g/cm3 (anhydrous)
1.3 g/cm3 (hexahydrate)
Melting point 192.4 °C (anhydrous)
100 °C (hexahydrate)
180 °C (sublimes)
Boiling point 120 °C (hexahydrate)
Solubility in water 43.9 g/100 ml (0 °C)
44.9 g/100 ml (10 °C)
45.8 g/100 ml (20 °C)
46.6 g/100 ml (30 °C)
47.3 g/100 ml (40 °C)
48.1 g/100 ml (60 °C)
48.6 g/100 ml (80 °C)
49 g/100 ml (100 °C)
Solubility soluble in hydrogen chloride, ethanol, chloroform, carbon tetrachloride
slightly soluble in benzene
Crystal structure Monoclinic, mS16
Space group C12/m1, No. 12
Octahedral (solid)
Tetrahedral (liquid)
Molecular shape Trigonal planar
(monomeric vapour)
Std molar
entropy So298
111 J·mol−1·K−1[1]
Std enthalpy of
formation ΔfHo298
−704 kJ·mol−1[1]
MSDS External MSDS
EU classification Corrosive (C)
R-phrases R34
S-phrases (S1/2), S7/8, S28, S45
NFPA 704
NFPA 704.svg
LD50 anhydrous:
380 mg/kg, rat (oral)
3311 mg/kg, rat (oral)
Related compounds
Other anions Aluminium fluoride
Aluminium bromide
Aluminium iodide
Other cations Boron trichloride
Gallium trichloride
Indium(III) chloride
Magnesium chloride
Related Lewis acids Iron(III) chloride
Boron trifluoride
Supplementary data page
Structure and
n, εr, etc.
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Aluminium chloride (AlCl3) is the main compound of aluminium and chlorine. It is white, but samples are often contaminated with iron trichloride, giving it a yellow colour. The solid has a low melting and boiling point. It is mainly produced and consumed in the production of aluminium metal, but large amounts are also used in other areas of chemical industry. The compound is often cited as a Lewis acid. It is an example of an inorganic compound that "cracks" at mild temperature, reversibly changing from a polymer to a monomer.