Aluminiumchlorid

Aluminiumchlorid, also known as aluminum trichloride, is a chemical compound with the formula AlCl3. It is a white to pale yellow crystalline solid that is highly hygroscopic. In the gas phase it tends to exist as the dimer Al2Cl6; in the solid state it forms polymeric networks. It is a strong Lewis acid used in a range of catalytic applications.

AlCl3 readily reacts with water to form hydrochloric acid and aluminum hydroxide: AlCl3 + 3 H2O → Al(OH)3 + 3 HCl, releasing heat. Because of its affinity for moisture, it is typically handled and stored under strictly dry conditions.

Industrial production is by direct chlorination of aluminium metal, yielding AlCl3. 2 Al + 3 Cl2 → 2 AlCl3. The compound can also be prepared by reacting aluminum compounds with hydrogen chloride under controlled conditions.

Uses include as a Lewis acid catalyst in Friedel-Crafts alkylation and acylation, dehydration reactions, and various organic syntheses. It is also used in the preparation of other aluminum chlorides and as a catalyst in some polymerization processes.

Safety: AlCl3 is corrosive and reactive with water; fumes contain hydrogen chloride; exposure can irritate skin, eyes, and the respiratory tract. It should be handled with appropriate personal protective equipment and stored in a dry, well-ventilated area away from moisture.