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| Names | |
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| IUPAC names
Zirconium(IV) fluoride Zirconium tetrafluoride | |
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| ChemSpider | |
| ECHA InfoCard | 100.029.107 
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| Properties | |
| Chemical formula | ZrF4 |
| Molar mass | 167.21 g/mol |
| Appearance | white crystalline powder |
| Density | 4.43 g/cm (20 °C) |
| Melting point | 910 °C (1,670 °F; 1,180 K) |
| Solubility in water | 1.32 g/100mL (20 °C) 1.388 g/100mL (25 °C) |
| Structure | |
| Crystal structure | Monoclinic, mS60 |
| Space group | C12/c1, No. 15 |
| Hazards | |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
| LD50 (median dose) | 98 mg/kg (oral, mouse) 98 mg/kg (oral, rat) |
| Related compounds | |
| Other anions | Zirconium(IV) chloride Zirconium(IV) bromide Zirconium(IV) iodide |
| Other cations | Titanium(IV) fluoride Hafnium(IV) fluoride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa).
 Y verify (what is ?)
Infobox references
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Zirconium(IV) fluoride describes members of a family inorganic compounds with the formula ZrF4(H2O)x. All are colorless, diamagnetic solids. Anhydrous Zirconium(IV) fluoride is a component of ZBLAN fluoride glass.
Structure
Three crystalline phases of ZrF4 have been reported, α (monoclinic), β (tetragonal, Pearson symbol tP40, space group P42/m, No 84) and γ (unknown structure). β and γ phases are unstable and irreversibly transform into the α phase at 400 °C.
Zirconium(IV) fluoride forms several hydrates. The trihydrate has the structure (μ−F)2[ZrF3(H20)3]2.
Preparation and reactions
Zirconium fluoride can be produced by several methods. Zirconium dioxide reacts with hydrogen fluoride and hydrofluoric acid to afford the anhydrous and monohydrates:
- ZrO2 + 4 HF → ZrF4 + 2 H2O
The reaction of Zr metal reacts at high temperatures with HF as well:
- Zr + 4 HF → ZrF4 + 2 H2
Zirconium dioxide reacts at 200 °C with solid ammonium bifluoride to give the heptafluorozirconate salt, which can be converted to the tetrafluoride at 500 °C:
- 2ZrO2 + 7 (NH4)HF2 → 2 (NH4)3ZrF7 + 4 H2O + NH3
- (NH4)3ZrF7 → ZrF4 + 3 HF + 3 NH3
Addition of hydrofluoric acid to solutions of zirconium nitrate precipitates solid monohydrate. Hydrates of zirconium tetrafluoride can be dehydrated by heating under a stream of hydrogen fluoride.
Zirconium fluoride can be purified by distillation or sublimation.
Zirconium fluoride forms double salts with other fluorides. The most prominent is potassium hexafluorozirconate, formed by fusion of potassium fluoride and zirconium tetrafluoride:
- ZrF4 + 2 KF → K2ZrF6
Applications
The major and perhaps only commercial application of zirconium fluoride is as a precursor to ZBLAN glasses.
Mixture of sodium fluoride, zirconium fluoride, and uranium tetrafluoride (53-41-6 mol.%) was used as a coolant in the Aircraft Reactor Experiment. A mixture of lithium fluoride, beryllium fluoride, zirconium fluoride, and uranium-233 tetrafluoride was used in the Molten-Salt Reactor Experiment. (Uranium-233 is used in the thorium fuel cycle reactors.)
References
- "Zirconium compounds (as Zr)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ Nielsen, Ralph (2000). "Zirconium and Zirconium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a28_543. ISBN 3527306730.
- Paul L. Brown; Federico J. Mompean; Jane Perrone; Myriam Illemassène (2005). Chemical thermodynamics of zirconium. Gulf Professional Publishing. p. 144. ISBN 0-444-51803-7.
- Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 965. ISBN 978-0-08-037941-8.
- Meshri, Dayal T. (2000), "Fluorine compounds, inorganic, titanium", Kirk-Othmer Encyclopedia of Chemical Technology, New York: John Wiley, doi:10.1002/0471238961.2009200113051908.a01, ISBN 9780471238966
- ORNL/TM-2006/12 Assessment of Candidate Molten Salt Coolants for the Advanced High-Temperature Reactor (AHTR), March 2006 (Accessed 2008/9/18)
| Zirconium compounds | |||||
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| Zr(II) | |||||
| Zr(III) | |||||
| Zr(IV) |
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