Bismuth trifluoride

Bismuth(III) fluoride or bismuth trifluoride is a chemical compound of bismuth and fluorine. The chemical formula is BiF3. It is a grey-white powder melting at 649°C.

Bismuth trifluoride
Names
IUPAC name
Bismuth(III) fluoride
Other names
Bismuth trifluoride
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.204
EC Number
  • 232-124-8
UNII
Properties
BiF3
Molar mass 265.97550 g/mol
Appearance grey-white powder
Density 5.32 g cm−3[1]
Melting point 649˚C[2]
Insoluble in water[1]
-61.0·10−6 cm3/mol
Structure
Orthorhombic, oP16, SpaceGroup = Pnma, No. 62 (β phase)
Hazards
Main hazards Irritant
GHS pictograms
GHS Signal word Danger
H314
P260, P264, P280, P301+330+331, P303+361+353, P304+340, P305+351+338, P310, P321, P363, P405, P501
NFPA 704 (fire diamond)
Flammability code 0: Will not burn. E.g. waterHealth code 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
0
1
0
Related compounds
Other anions
 Bismuth chloride
Other cations
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

It occurs in nature as the rare mineral gananite.

Synthesis

Bismuth trifluoride can be prepared by reacting bismuth(III) oxide with hydrofluoric acid:[2]

Bi2O3 + 6 HF → 2 BiF3 + 3 H2O

Structure

α-BiF3 has a cubic crystalline structure (Pearson symbol cF16, space group Fm-3m, No. 225). BiF3 is the prototype for the D03 structure, which is adopted by several intermetallics, including Mg3Pr, Cu3Sb, Fe3Si, and AlFe3,[3] as well as by the hydride LaH3.0.[4] The unit cell is face-centered cubic with Bi at the face centers and vertices, and F at the octahedral site (mid-edges, center), and tetrahedral sites (centers of the 8 sub cubes) - thus the primitive cell contains 4 Bi and 12 F.[5] Alternatively, with the unit cell shifted (1/4,1/4,1/4) the description can be of a fcc cell with face, edge, corner, and centers filled with F, and half (4 of) the octant centers with F, the other half with Bi (each octant type tetrahedrally arranged).[4] The edge length of the BiF3 cell is 0.5853 nm.[4]

β-BiF3 has the YF3 structure where the bismuth atom has distorted 9 coordination, tricapped trigonal prism.[6] This structure is generally considered to be ionic, and contrasts with fluorides of the lighter members of group 15, phosphorus trifluoride, PF3, arsenic trifluoride, AsF3 and antimony trifluoride, SbF3, where MX3 molecular units are present in the solid.[6]

Reactions

BiF3 is unaffected by water and is almost insoluble. It does not form complexes readily but the following, BiF3.3HF and BiF4− in NH4BiF4, are known. The addition compound H3BiF6 is hydrolysed by water forming BiOF.[7]

References
  1. http://www.alfa.com/content/msds/english/11844.pdf
  2. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
  3. De Graef, Marc; McHenry, Michael (eds.), "Appendix 1. Crystal Structure Descriptions", The Structure of Materials, Cambridge University Press, A1-2, A1-11
  4. Galasso, Francis S. (1970), Structure and Properties of Inorganic Solids: International Series of Monographs in Solid State Physics, Pergammon Press, 3.5. BiF3, DO3, Fm3m, Cubic. pp. 50–51
  5. Sólyom, Jenö (2007), Fundamentals of the Physics of Solids: Volume 1: Structure and Dynamics, p. 220, ISBN 978-3-540-72599-2
  6. Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN 0-19-855370-6
  7. Norman, Nicholas C (1998). Chemistry of arsenic, antimony, and bismuth. p. 88. ISBN 978-0-7514-0389-3.
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