| |
| Names | |
|---|---|
| Other names
Strontium difluoride | |
| Identifiers | |
3D model (JSmol) |
|
| ChemSpider |
|
| ECHA InfoCard | 100.029.091 
|
| EC Number |
|
PubChem CID |
|
| UNII | |
CompTox Dashboard (EPA) |
|
| |
| |
| Properties | |
| SrF2 | |
| Molar mass | 125.62 g/mol |
| Density | 4.24 g/cm3 |
| Melting point | 1,473 °C (2,683 °F; 1,746 K) |
| Boiling point | 2,460 °C (4,460 °F; 2,730 K) |
| 0.117 g/100 mL | |
Solubility product (Ksp) |
4.33×10−9[1] |
| −37.2·10−6cm3/mol | |
Refractive index (nD) |
1.439 @0.58 μm |
| Structure | |
| cubic crystal system, cF12 | |
| Fm3m, #225 | |
a = 5.80 Å, b = 5.80 Å, c = 5.80 Å α = 90°, β = 90°, γ = 90° | |
| Sr, 8, cubic F, 4, tetrahedral | |
| Hazards | |
| Flash point | Non-flammable |
| Related compounds | |
Other anions |
Strontium chloride Strontium bromide Strontium iodide |
Other cations |
beryllium fluoride magnesium fluoride calcium fluoride barium fluoride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Strontium fluoride, SrF2, also called strontium difluoride and strontium(II) fluoride, is a fluorideofstrontium. It is a brittle white crystalline solid. In nature, it appears as the very rare mineral strontiofluorite.[2][3]
Strontium fluoride is prepared by the action of hydrofluoric acidonstrontium carbonate.[4]
The solid adopts the fluorite structure. In the vapour phase the SrF2 molecule is non-linear with an F−Sr−F angle of approximately 120°.[5] This is an exception to VSEPR theory which would predict a linear structure. Ab initio calculations have been cited to propose that contributions from d orbitals in the shell below the valence shell are responsible.[6] Another proposal is that polarization of the electron core of the strontium atom creates an approximately tetrahedral distribution of charge that interacts with the Sr−F bonds.[7]
It is almost insoluble in water (its Ksp value is approximately 2.0x10−10 at 25 degrees Celsius).
It irritates eyes and skin, and is harmful when inhaled or ingested.
Similar to CaF2 and BaF2, SrF2 displays superionic conductivity at elevated temperatures.[8]
Strontium fluoride is transparent to light in the wavelengths from vacuum ultraviolet (150 nm) to infrared (11 μm). Its optical properties are intermediate to calcium fluoride and barium fluoride.[9]
Strontium fluoride is used as an optical material for a small range of special applications, for example, as an optical coating on lenses and also as a thermoluminescent dosimeter crystal.
Another use is as a carrier of strontium-90 radioisotopeinradioisotope thermoelectric generators.
| Authority control databases: National |
|
|---|
