Bismuth trifluoride is a chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 of bismuth

Bismuth

Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...

 and fluorine

Fluorine

Fluorine is the chemical element with atomic number 9, represented by the symbol F. It is the lightest element of the halogen column of the periodic table and has a single stable isotope, fluorine-19. At standard pressure and temperature, fluorine is a pale yellow gas composed of diatomic...

. 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

Hydrofluoric acid

Hydrofluoric acid is a solution of hydrogen fluoride in water. It is a valued source of fluorine and is the precursor to numerous pharmaceuticals such as fluoxetine and diverse materials such as PTFE ....

:

Bi₂O₃ + 6 HF → BiF₃ + 3 H₂O

Structure

α-BiF₃ has a cubic crystalline structure (Pearson symbol

Pearson symbol

The Pearson symbol, or Pearson notation, is used in crystallography as a means of describing a crystal structure, and was originated by W.B. Pearson. The symbol is made up of two letters followed by a number. For example:* Diamond structure, cF8...

 cF16, space group

Space group

In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...

 Fm-3m, No. 225). β-BiF₃ has the YF₃

Yttrium(III) fluoride

Yttrium fluoride is an inorganic chemical compound with the chemical formula YF3. It is not known naturally in 'pure' form. The fluoride minerals containing essential yttrium include tveitite- 6Ca6Ca6F42 and gagarinite- NaCaY6...

 structure where the bismuth atom has distorted 9 coordination, tricapped trigonal prism. This structure is generally considered to be ionic, and contrasts with fluorides of the lighter members of group 5, phosphorus trifluoride

Phosphorus trifluoride

Phosphorus trifluoride , is a colorless and odorless gas. It is highly toxic and it reacts slowly with water. Its main use is as a ligand in metal complexes...

, PF₃, arsenic trifluoride

Arsenic trifluoride

Arsenic trifluoride is a chemical compound of arsenic and fluorine with the formula AsF3. It is a colorless liquid which reacts readily with water.-Preparation and properties:It can be prepared by reacting hydrogen fluoride, HF, with arsenic trioxide:...

, AsF₃ and antimony trifluoride

Antimony trifluoride

Antimony trifluoride is the inorganic compound with the formula SbF3. Sometimes called Swart's reagent, is one of two principal fluorides of antimony, the other being SbF5. It appears as a white solid...

, SbF₃, where MX₃ molecular units are present in the solid.