Niobium(V) fluoride

Names
IUPAC names Niobium(V) fluoride Niobium pentafluoride
Identifiers
CAS Number	7783-68-8 Y
3D model (JSmol)	Interactive image
ChemSpider	74197
ECHA InfoCard	100.029.109
EC Number	232-020-2
PubChem CID	82217
UNII	T86H76439H Y
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). Y verify (what is YN ?) 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.