Further Insights into the Chemical Synthesis of F 2 and on Drying moist HF.

It is well established that solid K 2 MnF 6 reacts with excess SbF 5 forming elemental F 2 . However, if the reaction is carried out in anhydrous HF (aHF) as a solvent, this is surprisingly not the case. Instead, the green Mn(IV) compound K 3 [(Mn IV F)(SbF 6 ) 5 ]F is obtained. The reductive elimination of F 2 was not observed under the applied conditions. The compound was characterized by its crystal structure, by Raman spectroscopy, and by quantum-chemical solid-state calculations. It crystallizes in the monoclinic space group P 2 1 / c , mP 164, with the lattice parameters a = 12.2393(13), b = 12.167(2), c = 20.115(5) Å, β = 110.805(8)°, V = 2800.1(9) Å 3 , Z = 4 at T = 200 K. As the use of strictly anhydrous HF is crucial in this and other similar reactions, methods for drying moist HF are discussed.