Tantalum(V) fluoride

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Tantalum(V) fluoride
Image:Tantalum(V) fluoride.jpg
Other names tantalum pentafluoride
Identifiers
CAS number [7783-71-3]
RTECS number WW5775000
Properties
Molecular formula TaF5
Molar mass 275.95 g/mol
Appearance white powder
Density 4.74 g/cm3, solid
Melting point

96.8 °C

Boiling point

229.5 °C

Solubility in water decomposes
Structure
Dipole moment 0 D
Hazards
EU classification not listed
Main hazards HF source
R-phrases 34
S-phrases 26-27-28-36/37/39-45
Flash point nonflammable
Related compounds
Related compounds TaCl5
NbCl5
WF6
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Tantalum(V) fluoride is the chemical compound with the formula. TaF5. Characteristic of other penta and hexafluorides, TaF5 is volatile.

Contents

[edit] Preparation

It is prepared by treating Ta metal with fluorine gas.[1] NbF5 is prepared similarly.

[edit] Structure

Solid and molten TaF5 is tetrameric, consisting of four TaF4 centers linked together via bridging fluoride atoms. Gaseous TaF5 adopts the trigonal pyramidal structure, with D3h symmetry.[2]

[edit] Reactions and derivatives

The tendency of TaF5 to form clusters in the solid state indicates the Lewis acidity of the monomer. Indeed, TaF5 reacts with fluoride sources to give the ions [TaF6]-, [TaF7]2-, and [TaF8]3-. With neutral Lewis bases, such as diethyl ether TaF5 forms adducts.

[edit] References

  1. ^ Priest, H. F. “Anhydrous Metal Fluorides” Inorganic Syntheses McGraw-Hill: New York, 1950; Vol. 3, pages 171-183.
  2. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
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