Bismuth pentafluoride

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Bismuth pentafluoride
Bismuth-pentafluoride-chains-from-xtal-1971-3D-balls.png
Bismuth-pentafluoride-chains-from-xtal-1971-3D-SF.png
Identifiers
CAS number 7787-62-4
PubChem 123260
ChemSpider 21172752
ChEBI CHEBI:30426 YesY
Jmol-3D images Image 1
Properties
Molecular formula BiF5
Molar mass 303.97 g mol−1
Appearance long white needles,[1] colourless crystalline solid[2]
Density 5.40 g cm−3[1]
Melting point 151.4 °C,[2] 154.4 °C[1]
Boiling point 230 °C[1][2]
Structure
Coordination
geometry
octahedral Bi
Hazards
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Related compounds
Other anions bismuth trichloride, bismuth tribromide, bismuth triiodide, pentamethylbismuth
Other cations phosphorus pentafluoride, arsenic pentafluoride, antimony pentafluoride
Related compounds bismuth trifluoride
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Bismuth pentafluoride, BiF5, is a chemical compound of bismuth and fluorine.

Structure[edit]

BiF5 is polymeric and consists of linear chains of trans-bridged corner sharing BiF6 octahedra.[1][3] This is the same structure as α-UF5 and is in contrast to bismuth trifluoride, BiF3, which is ionic and adopts the YF3 structure.[1]

Bismuth-pentafluoride-chain-from-xtal-1971-3D-balls.png
Bismuth-pentafluoride-chain-from-xtal-1971-3D-SF.png
Bismuth-pentafluoride-chain-packing-from-xtal-1971-3D-balls.png Bismuth-pentafluoride-chain-packing-from-xtal-1971-3D-SF.png
(BiF5) chain
packing of chains

Preparation[edit]

BiF5 can be prepared by reacting BiF3 with F2 at 500 °C.[2]

BiF3 + F2 → BiF5

An alternative synthesis uses ClF3 as the fluorinating agent at 350 °C.[4]

BiF3 + ClF3 → BiF5 + ClF

Reactions[edit]

Bismuth pentafluoride is the most reactive of the Group 15 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.[1]

BiF5 also reacts with alkali metal fluorides, MF, to form hexafluorobismuthates, M[BiF6], containing the hexafluorobismuthate anion, [BiF6].[2]

References[edit]

  1. ^ a b c d e f g Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 561–563. ISBN 0080379419. 
  2. ^ a b c d e Holleman, A. F.; Wiberg, E. (2001), Inorganic Chemistry, San Diego: Academic Press, pp. 769–770, ISBN 0-12-352651-5 
  3. ^ C. Hebecker (1971). "Zur Kristallstruktur von Wismutpentafluorid". Z. anorg. allg. Chem. 384 (2): 111–114. doi:10.1002/zaac.19713840204. 
  4. ^ A. I. Popov, A. V. Scharabarin, V. F. Sukhoverkhov, N. A. Tchumaevsky (1989). "Synthesis and properties of pentavalent antimony and bismuth fluorides". Z. anorg. allg. Chem. 576 (1): 242–254. doi:10.1002/zaac.19895760128.