Niobium(V) fluoride

Niobium(V) fluoride
Names
	IUPAC names Niobium(V) fluoride; Niobium pentafluoride
Identifiers
CAS Number	7783-68-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	74197;
ECHA InfoCard	100.029.109
EC Number	232-020-2;
PubChem CID	82217;
UNII	T86H76439H ;
CompTox Dashboard (EPA)	DTXSID0064832 ;
	InChI InChI=1S/5FH.Nb/h5*1H;/q;;;;;+5/p-5 Key: AOLPZAHRYHXPLR-UHFFFAOYSA-I;
	SMILES F[Nb](F)(F)(F)F;
Properties
Chemical formula	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)
Solubility in water	reacts
Solubility	slightly soluble in chloroform, carbon disulfide, sulfuric acid
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H312, H314, H332
Precautionary statements	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	Niobium(V) chloride; Niobium(V) bromide; Niobium(V) iodide
Other cations	Vanadium(V) fluoride; Tantalum(V) fluoride
Related niobium fluorides	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). verify (what is ?) Infobox references

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

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

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

NIST Standard Reference Database

References

^ 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.

[Ullmann-1] 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.

[2] Homer F. Priest (1950). "Anhydrous Metal Fluorides". Inorganic Syntheses. Vol. 3. p. 171. doi:10.1002/9780470132340.ch47.

[3] Edwards, A. J. (1964). "717. The structures of niobium and tantalum pentafluorides". Journal of the Chemical Society (Resumed): 3714. doi:10.1039/jr9640003714.

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