Aluminum Fluoride AlF3 Encyclopedia
Aluminum Fluoride AlF3 is an inorganic compound with the chemical formula AlF3. It can be prepared by reacting aluminum hydroxide or metallic aluminum with hydrogen fluoride. The solid structure is similar to that of rhenium trioxide (ReO3) and consists of twisted hexa-Aluminum Fluoride AlF3 (AlF6) regular octahedra. Unlike other halides of aluminum, AlF3 is refractory. AlCl3, AlBr3 and AlI3 are dimers in liquid and gaseous states. At about 1000°C, the gaseous Aluminum Fluoride AlF3 has a planar triangular configuration with the D3h symmetry group. The Al-F bond is 163pm long.
Aluminum Fluoride AlF3 can increase the conductivity of the electrolyte and reduce the melting point of alumina, so it is an important additive in the production of electrolytic aluminum.