Stabilization of [WF5]+ by Bidentate N‐Donor Ligands

Transition‐metal hexafluorides do not exhibit fluoride‐ion donor properties in the absence of donor ligands. We report the first synthesis of donor‐stabilized MF₅]⁺ derived from a transition‐metal hexafluoride via fluoride‐ion abstraction using WF₆(L) (L=2,2′‐bipy, 1,10‐phen) and SbF₅(OSO) in SO₂. The WF₅(L)]Sb₂F₁₁] salts and WF₅(1,10‐phen)]SbF₆]?SO₂ have been characterized by X‐ray crystallography, Raman spectroscopy, and multinuclear NMR spectroscopy. The reaction of WF₆(2,2′‐bipy) with an equimolar amount of SbF₅(OSO) reveals an equilibrium between WF₅(2,2′‐bipy)]⁺ and the WF₄(2,2′‐bipy)₂]²⁺ dication, as determined by ¹⁹F NMR spectroscopy. The geometries of the cations in the solid state are reproduced by gas‐phase geometry optimizations (DFT‐B3LYP), and NBO analyses reveal that the positive charges of the cations are stabilized primarily by compensatory σ‐electron donation from the N‐donor ligands.