Bismuth pentafluoride explained

Bismuth pentafluoride is an inorganic compound with the formula BiF₅. It is a white solid that is highly reactive. The compound is of interest to researchers but not of particular value.

Structure

BiF₅ is polymeric and consists of linear chains of trans-bridged corner sharing BiF₆ octahedra.^[1] This is the same structure as α-UF₅.

Preparation

BiF₅ can be prepared by treating BiF₃ with F₂ at 500 °C.

BiF₃ + F₂ → BiF₅

In an alternative synthesis, ClF₃ is the fluorinating agent at 350 °C.^[2]

BiF₃ + ClF₃ → BiF₅ + ClF

Reactions

Bismuth pentafluoride is the most reactive of the pnictogen pentafluorides and is an extremely strong fluorinating agent. It reacts vigorously with water to form ozone and oxygen difluoride, and with iodine or sulfur at room temperature. BiF₅ fluorinates paraffin oil (hydrocarbons) to fluorocarbons above 50 °C and oxidises UF₄ to UF₆ at 150 °C. At 180 °C, bismuth pentafluoride fluorinates Br₂ to BrF₃ and Cl₂ to ClF.

BiF₅ also reacts with alkali metal fluorides, MF, to form hexafluorobismuthates, M[BiF₆], containing the hexafluorobismuthate anion, [BiF₆]⁻. Bismuth pentafluorude in hydrofluoric acid solvent also reacts with nickel fluoride to form the nickel salt of this anion, which can be incorporated into a complex with acetonitrile.^[3]

Notes and References

1. . 1971 . 384 . 111–114 . 10.1002/zaac.19713840204 . Zur Kristallstruktur von Wismutpentafluorid . C. Hebecker . 2 .
2. Z. Anorg. Allg. Chem. . 1989 . 576 . 242–254 . 10.1002/zaac.19895760128 . Synthesis and properties of pentavalent antimony and bismuth fluorides . A. I. Popov . A. V. Scharabarin . V. F. Sukhoverkhov . N. A. Tchumaevsky . 1 .
3. Inorganic Chemistry. 1988 . 27 . 1389–1393 . 10.1021/ic00281a018 . Preparation and characterization of nickel(2+) hexafluorobismuthate(1-) and of the ternary adducts [Ni(CH3CN)6](BiF6)2 and [Ni(CH3CN)6](SbF6)2. Crystal structure of hexakis(acetonitrile-d3)nickel(2+) hexafluoroantimonate . Roland Bougon . Pierrette Charpin . Karl O. Christe . Jacques Isabey . Monique Lance . Martine Nierlich . Julien Vigner . William W. Wilson . 8 .