Like magnesium fluoride it is used as a low-index optical thin film, particularly when far UV transparency is required. Together with zirconium fluoride, aluminium fluoride is an ingredient for the production of fluoroaluminate glasses. The observation that aluminium fluoride can bind to and activate heterotrimeric G proteins has proven to be useful for the study of G protein activation in vivo, for the elucidation of three-dimensional structures of several GTPases, and for understanding the biochemical mechanism of GTP hydrolysis, including the role of GTPase-activating proteins. Īluminium fluoride complexes are used to study the mechanistic aspects of phosphoryl transfer reactions in biology, which are of fundamental importance to cells, as phosphoric acid anhydrides such as adenosine triphosphate and guanosine triphosphate control most of the reactions involved in metabolism, growth and differentiation. It is into this molten salt that aluminium oxide is dissolved and then electrolyzed to give bulk Al metal. Together with cryolite, it lowers the melting point to below 1000 ☌ and increases the conductivity of the solution. Applications Īluminium fluoride is an important additive for the production of aluminium by electrolysis. Like most gaseous metal trifluorides, AlF 3 adopts a planar structure upon evaporation. The Al–F bond lengths of this gaseous molecule are 163 pm. In the gas phase aluminium fluoride exists as trigonal molecules of D 3h symmetry. Also they have low melting points and evaporate readily to give dimers. The other trihalides of aluminium in the solid state differ, AlCl 3 has a layer structure and AlBr 3 and AlI 3, are molecular dimers. Because of its three-dimensional polymeric structure, AlF 3 has a high melting point. Each fluoride is connected to two Al centers. Structure Īccording to X-ray crystallography, anhydrous AlF 3 adopts the rhenium trioxide motif, featuring distorted AlF 6 octahedra. A related, exceedingly rare mineral, is zharchikhite, Al(OH) 2F.

The anhydrous form appears as the relatively recently (as of 2020) recognized mineral óskarssonite.

For small scale laboratory preparations, AlF 3 can also be prepared by treating aluminium hydroxide or aluminium metal with hydrogen fluoride.Īluminium fluoride trihydrate is found in nature as the rare mineral rosenbergite. H 2SiF 6 + Al 2O 3 + 3 H 2O → 2 AlF 3 + SiO 2 + 4 H 2OĪlternatively, it is manufactured by thermal decomposition of ammonium hexafluoroaluminate. The majority of aluminium fluoride is produced by treating alumina with hydrogen fluoride at 700 ☌: Hexafluorosilicic acid may also be used make aluminium fluoride.

xH 2O, these compounds include monohydrate ( x = 1), two polymorphs of the trihydrate ( x = 3), a hexahydrate ( x = 6), and a nonahydrate ( x = 9).

Several occur as minerals.Īside from anhydrous AlF 3, several hydrates are known. Anhydrous AlF 3 is used in the production of aluminium metal. Aluminium fluoride refers to inorganic compounds with the formula AlF 3

Aluminium melting point