Aluminum Iodide

Aluminum iodide is an inorganic substance, which belongs to the class of binary compounds, it can also be regarded as a salt of aluminum and hydroiodic acid. It is a solid stuff of white color with a yellowish tint. Its molar/atomic mass is 407.69.
Aluminium Iodide
Outside, aluminum iodide is white plates. Its melting temperature is equal to 191°C and its boiling temperature is equal to 386°S, its density is equal to 3,98 g/cm3. It dissolves in water, alcohol, ether, carbon sulphide, pyridine. Its molar electric conductivity at infinite dilution at 25°C is equal to 419,4 Cm.сm2/mole. It is got directly from elements or by a reaction between hydroiodic acid and aluminum. Aluminum iodide possesses the following chemical properties:

* It is reactive with concentrated sulfuric acid.

* While air moisture absorption, it partially decomposes with formation of a subsalt, the same salt is formed at heating of crystalline hydrate.

* At heating of the aluminum iodide solution, a sediment of aluminum hydroxide precipitates out.

* Its partial dimerization occurs in gas phase at temperature of above 250 °C.

* While dissolution in water, the dissociation accompanied by hydration and the subsequent multi-step hydrolysis of a cation takes place; at the same time, an acid medium is created.

* It forms sediment of aluminum hydroxide with diluted alkalis, it decomposes with formation of tetrahydroxalluminate.

Aluminum iodide is used in organic chemistry as catalyst.

It is also used in veterinary medicine. The aerosol of aluminum iodide is prescribed for group treatment of pigs with pneumonia.

Aluminum iodide is able to cause burns of the skin and mucosae. It can cause an allergic reaction.


Generally, aluminum iodide is applied in organic chemistry as a catalyst. It is used as a reagent for the breakage of precise types of C-O and N-O components. This substance cleaves aryl ethers and deoxygenates epoxides.

There is one more use of the compound in veterinary medicine. The thing refers to its aerosol form. The aluminum iodide aerosol is also used for an aerosol disinfection of stall houses for purposes of refinement of preventive events in case of respiratory diseases of calves or pigs.

Formula for Aluminum Iodide

Aluminum iodide can be received directly by a reaction of a powdered aluminum and an iodine.

Its empirical formula (Hill’s system) is: AlI3

Its structural formula is: AlI3

formula for Aluminum Iodide

Below you can find reactions with aluminum iodide:

MX3 + 3ROH → M(OH)3 + 3RX where M = Al, Cr, Fe, Ti, La; X = Cl, F, Br, I, R are Li, Na, K, Rb, Cs, NH4

Al(OH)3 + 3HX → AlX3 + 3H2O where X = F, Cl, Br, I (No. 3)

M2O3 + 6HX = 2MX3 + 3H2O where M = Fe, Al, Cr, La, Sc, Y, X are F, Cl, Br, I (No. 3)

2Al + 3Hal22AlHal3 where Hal = Cl, Br, I

NaAlO2 + 4HX → NaX + AlX3 + 2H2O where X = Cl, F, Br, I

Properties Aluminum Iodide

Molar mass     407.69495 g/mol (anhydrous) 515.786 g/mol (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
Density       3.98 g/cm3 (anhydrous) 2.63 g/cm3 (hexahydrate)