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Names | |
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IUPAC names
Niobium(V) fluoride
Niobium pentafluoride | |
Identifiers | |
3D model (JSmol)
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ChemSpider | |
ECHA InfoCard | 100.029.109 |
EC Number |
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PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
F5Nb | |
Molar mass | 187.89839 g·mol−1 |
Appearance | colorless hygroscopic solid |
Density | 3.293 g/cm3 |
Melting point | 72 to 73 °C (162 to 163 °F; 345 to 346 K) |
Boiling point | 236 °C (457 °F; 509 K) |
reacts | |
Solubility | slightly soluble in chloroform, carbon disulfide, sulfuric acid |
Hazards | |
GHS labelling: | |
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Warning | |
H302, H312, H314, H332 | |
P260, P261, P264, P270, P271, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P321, P322, P330, P363, P405, P501 | |
Flash point | Non-flammable |
Related compounds | |
Other anions
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Niobium(V) chloride Niobium(V) bromide Niobium(V) iodide |
Other cations
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Vanadium(V) fluoride Tantalum(V) fluoride |
Related niobium fluorides
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Niobium(III) fluoride Niobium(IV) fluoride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Niobium(V) fluoride, also known as niobium pentafluoride, is the inorganic compound with the formula NbF5. It is a colorless solid.[1]
Preparation and structure
[edit]Niobium pentafluoride is obtained by treatment of any niobium compound with fluorine:[2]
- 2 Nb + 5 F2 → 2 NbF5
- 2 NbCl5 + 5 F2 → 2 NbF5 + 5 Cl2
As shown by X-ray crystallography, the solid consists of tetramers [NbF5]4. This structure is related to that for WOF4.[3]
Reactions
[edit]It reacts with hydrogen fluoride to give H2NbF7, a superacid. In hydrofluoric acid, NbF5 converts to [NbF7]2- and [NbF5O]2-. The relative solubility of K2[MFO] (M = Nb, Ta) is the basis of the Marignac process for separation of Nb and Ta.
NbCl5 forms a dimeric structure (edge-shared bioctahedron) in contrast to the corner-shared tetrameric structure of the fluoride.
External links
[edit]References
[edit]- ^ Joachim Eckert; Hermann C. Starck (2005). "Niobium and Niobium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_251. ISBN 3527306730.
- ^ Homer F. Priest (1950). "Anhydrous Metal Fluorides". Inorganic Syntheses. Vol. 3. p. 171. doi:10.1002/9780470132340.ch47.
- ^ Edwards, A. J. (1964). "717. The structures of niobium and tantalum pentafluorides". Journal of the Chemical Society (Resumed): 3714. doi:10.1039/jr9640003714.