Bismuth trifluoride

Bismuth trifluoride
IUPAC name Bismuth(III) fluoride
Other names Bismuth trifluoride
Identifiers
CAS number	7787-61-3
PubChem	82233
ChemSpider	21172751
Jmol-3D images	{{#if:[F-].[F-].[F-].[BiH3+3]|Image 1
SMILES [F-].[F-].[F-].[BiH3+3]
InChI InChI=1/Bi.3FH.3H/h;3*1H;;;/q+3;;;;;;/p-3/rBiH3.3FH/h1H3;3*1H/q+3;;;/p-3 Key: GRQDKISMHISLGB-IZWAAGQTAY
Properties
Molecular formula	BiF3
Molar mass	265.97550 g/mol
Appearance	grey-white powder
Density	5.32 g cm-3[1]
Melting point	649˚C[2]
Solubility in water	Insoluble in water[1]
Structure
Crystal structure	Orthorhombic, oP16, SpaceGroup = Pnma, No. 62 (β phase)
Hazards
R-phrases	R36/38
S-phrases	S26
Main hazards	Irritant
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

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.

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). β-BiF₃ has the YF₃ structure where the bismuth atom has distorted 9 coordination, tricapped trigonal prism.^[3] This structure is generally considered to be ionic, and contrasts with fluorides of the lighter members of group 5, phosphorus trifluoride, PF₃, arsenic trifluoride, AsF₃ and antimony trifluoride, SbF₃, where MX₃ molecular units are present in the solid.^[3]

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.^[4]

References