Aluminum Chloride

aluminum chloride (AlCl₂) A white covalent solid that fumes in moist air:
AlCl₃ + 3H₂O → Al(OH)₃ + 3HCl
It is prepared by heating aluminum in dry chlorine or dry hydrogen chloride. Vapordensity measurements show that its structure is a dimer; it consists of Al₂Cl₆ molecules in the vapor. The AlCl₃ structure would be electron-deficient. Aluminum chloride is used in Friedel–Crafts reactions
in organic preparations.