Low temperature preparation and uses of potent oxidizers

Because electronegativity of an oxidation state is low in an anion, salts of the high oxidation-state species [AgF4]− and [NiF6]2− can be easily made, at 0 °C, in liquid anhydrous HF (aHF) made basic with alkali fluorides. The containers are transparent fluorocarbon, and the F2 is photo-dissociated. The [NiF6]2− salts, and the metastable binary fluorides NiF4 and NiF3, derived from them, are efficient fluorinating agents for the conversion of hydrido compounds to their fully fluorinated relatives. With F2 in aHF made acidic with fluoride-ion acceptors (e.g. MF5, M = As, Sb, Bi) attained oxidation-states are often lower (e.g. AgII, AuII) because of the higher electronegativity in cations. Cationic AgIII and NiIV species (derived from the anions) are sufficiently long-lived, and potent, to generate the most powerfully oxidizing hexafluorides of the second and third transition series (i.e. [MF6], M = Pt, Ru, Rh). This synthesis is especially valuable for RhF6, and has provided for the reinvestigation of the interaction of it with O2. It is proposed that the unexpectedly large unit cell of O2RhF6 is a result of the presence of neutral O2 and neutral RhF6 as well as O2+ and RhF6− in the lattice.