Vanadium(III) fluoride is the
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
with the formula
V F3. This yellow-green, refractory solid is obtained in a two-step procedure from V
2O
3.
Similar to other transition-metal fluorides (such as
MnF2), it exhibits magnetic ordering at low temperatures (e.g. V
2F
6.4H
2O orders below 12 K
[S. Nakhal et al., Z. Kristallogr. 228, 347 (2013).]).
Preparation
The first step entails conversion to the hexafluorovanadate(III) salt using
ammonium
The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary a ...
bifluoride
The bifluoride ion is an inorganic anion with the chemical formula . The anion is colorless. Salts of bifluoride are commonly encountered in the reactions of fluoride salts with hydrofluoric acid. The commercial production of fluorine involves e ...
:
:V
2O
3 + 6 (NH
4)HF
2 → 2 (NH
4)
3VF
6 + 3 H
2O
In the second step, the hexafluorovanadate is thermally decomposed.
:(NH
4)
3VF
6 → 3 NH
3 + 3
HF + VF
3
The thermal decomposition of ammonium salts is a relatively common method for the preparation of inorganic solids.
VF
3 can also be prepared by treatment of V
2O
3 with HF.
VF
3 is a crystalline solid with 6 coordinate vanadium atoms with bridging fluorine atoms. The magnetic moment indicates the presence of two unpaired electrons.
References
*
Fluorides
Metal halides
Vanadium(III) compounds
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