Chemistry:Chromium pentafluoride
| File:CrF5cain.tif | |
| Names | |
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| IUPAC name
Chromium(V) fluoride
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| Other names
Chromium fluoride, Chromium(V) fluoride, Pentafluorochromium, Pentafluoridochromium
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
PubChem CID
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| Properties[1] | |
| CrF5 | |
| Molar mass | 146.988 g/mol |
| Appearance | red crystals |
| Density | 2.89 g/cm3 |
| Melting point | 34 °C (93 °F; 307 K) |
| Boiling point | 117 °C (243 °F; 390 K) |
| Structure[2] | |
| orthorhombic | |
| Pbcm, No. 57 | |
a = 782.9 pm, b = 753.4 pm, c = 551.8 pm
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Formula units (Z)
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4 |
| octahedral | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Chromium pentafluoride is the inorganic compound with the chemical formula CrF5.[3] It is a red volatile solid that melts at 34 °C.[1] It is the highest known chromium fluoride, since the hypothetical chromium hexafluoride has not yet been synthesized.[4]
Chromium pentafluoride is one of the products of the action of fluorine on a mixture of potassium and chromic chlorides.[5]
In terms of its structure, the compound is a one-dimensional coordination polymer. Each Cr(V) center has octahedral molecular geometry.[2] It has the same crystal structure as vanadium pentafluoride.[6]
Chromium pentafluoride is strongly oxidizing, able to fluorinate the noble gas xenon and oxidize dioxygen to dioxygenyl.[2] Due to this property, it decomposes readily in the presence of reducing agents, and easily hydrolyses to chromium(III) and chromium(VI).[7]
Reactions
Chromium pentafluoride can react with Lewis bases such as caesium fluoride and nitryl fluoride to give the respective hexafluorochromate(V) salt.[8]
- CrF5 + CsF → CsCrF6
Chromium pentafluoride can also react with the Lewis acid antimony pentafluoride to give the CrF5·2SbF5 adduct. The adduct was found to be a strong oxidizing agent, liquid at room temperature with a melting point of −23 °C.[8]
See also
- Chromium difluoride
- Chromium trifluoride
- Chromium tetrafluoride
References
- ↑ 1.0 1.1 Perry, Dale L. (2011). Handbook of Inorganic Compounds, Second Edition. Boca Raton, Florida: CRC Press. p. 125. ISBN 978-1-43981462-8. https://books.google.com/books?id=SFD30BvPBhoC. Retrieved 2014-01-10.
- ↑ 2.0 2.1 2.2 Shorafa, H.; Seppelt, K. (2009). "The structures of CrF5 and CrF5*SbF5". Zeitschrift für anorganische und allgemeine Chemie 635 (1): 112–114. doi:10.1002/zaac.200800378.
- ↑ Chromium(VI) Handbook. CRC Press. 2004. p. 30. ISBN 9780203487969.
- ↑ Riedel, Sebastian; Kaupp, Martin (2009). "The highest oxidation states of the transition metal elements". Coordination Chemistry Reviews 253 (5–6): 606–624. doi:10.1016/j.ccr.2008.07.014.
- ↑ A. G. Sharpe (2012). J.H. Simons. ed. Fluorine Chemistry. 2. Elsevier. p. 24. ISBN 9780323145435.
- ↑ A. G. Sharpe (1983). Advances in Inorganic Chemistry. 27. Academic Press. p. 103. ISBN 9780080578767.
- ↑ Amit Aora (2005). Text Book Of Inorganic Chemistry. Discovery Publishing House. p. 649.
- ↑ 8.0 8.1 Brown, S. D.; Loehr, T. M.; Gard, G. L. (1976). "The Chemistry of chromium pentafluoride II. Reaction with inorganic systems" (in en). Journal of Fluorine Chemistry 7 (1): 19–32. doi:10.1016/S0022-1139(00)83979-2. ISSN 0022-1139. https://www.sciencedirect.com/science/article/pii/S0022113900839792.
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