Hydrogen fluoride solvent system. Part III. Solutions of the acids SbF5, AsF5, and PF5. Evidence for the As2F11 ? ion

Abstract
Cryoscopic measurements on solutions of antimony pentafluoride in HF confirm that it is a strong 1 : 1 electrolyte in dilute solutions. Cryoscopic and conductimetric measurements show that arsenic pentafluoride dissolves to form the strong electrolyte H2F+As2F11 . The dimeric anion As2F11 has been isolated as the tetraethylammonium salt. Phosphorus pentafluoride appears to be a non-electrolyte in this solvent.