Manganese trioxide fluoride is an inorganic compound with the formula . A green diamagnetic liquid, the compound has no applications, but it is of some academic interest as a rare example of a metal trioxide fluoride.
The compound was detected in the 1880s but was only purified and crystallized much more recently. It can be prepared by hydrofluoric acid and potassium permanganate:
crystallizes as a monomer, as confirmed by X-ray crystallography. The molecules are tetrahedral with Mn-O and Mn-F distances of 1.59 and 1.72 Å, respectively.
In contrast with , and have more complex structures as solids. The Re compound crystallizes as chains or rings consisting of fluoride-bridge octahedra. crystallizes as dimers with fluoride bridges. The rhenium compound also forms stable adducts with Lewis bases, whereas the is unstable in the presence of Lewis bases. References