Ammonium hexafluoroaluminate

Ammonium hexafluoroaluminate is an inorganic compound with the chemical formula of (NH₄)₃[AlF₆]. It is a white solid. Upon heating, it converts to aluminium trifluoride, a reaction that releases hydrogen fluoride. It has also been used as a precursor to zeolites.

Preparation

Ammonium hexafluoroaluminate can be obtained by the reaction of ammonium fluoride and aluminium hydroxide.

$\mathrm{6}\mathrm{N}{\mathrm{H}}_{\mathrm{4}}\mathrm{F}\mathrm{+}\mathrm{A}\mathrm{l}\mathrm{(}\mathrm{O}\mathrm{H}{\mathrm{)}}_{\mathrm{3}}\mathrm{⟶}\mathrm{(}\mathrm{N}{\mathrm{H}}_{\mathrm{4}}{\mathrm{)}}_{\mathrm{3}}\mathrm{[}\mathrm{A}\mathrm{l}{\mathrm{F}}_{\mathrm{6}}\mathrm{]}\mathrm{+}\mathrm{3}\mathrm{N}{\mathrm{H}}_{\mathrm{4}}\mathrm{O}\mathrm{H}$