Vanadium pentafluoride

Vanadium(V) fluoride
Names
	IUPAC name Vanadium(V) fluoride
	Other names Vanadium pentafluoride
Identifiers
CAS Number	7783-72-4 ;
3D model (JSmol)	Interactive image ;
ECHA InfoCard	100.029.112
EC Number	232-023-9;
PubChem CID	13416578 ;
UNII	1GNN7H50UE ;
	InChI InChI=1S/5FH.V/h5*1H;/q;;;;;+5/p-5 Key: NFVUDQKTAWONMJ-UHFFFAOYSA-I;
	SMILES [F-].[F-].[F-].[F-].[F-].[V+5];
Properties
Chemical formula	VF5
Molar mass	145.934
Appearance	colorless solid
Density	2.502 g/cm3 (solid)
Melting point	19.5 °C (67.1 °F; 292.6 K)
Boiling point	48.3 °C (118.9 °F; 321.4 K)
Related compounds
Other cations	Niobium(V) fluoride ; Tantalum(V) fluoride
Related Vanadium compounds	Vanadium(V) oxide ; Vanadium trifluoride
	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

Last updated January 19, 2024

Vanadium(V) fluoride is the inorganic compound with the chemical formula VF₅. It is a colorless volatile liquid^[1] that freezes near room temperature. It is a highly reactive compound, as indicated by its ability to fluorinate organic substances.^[2]

Properties and structure

The compound is exclusively a monomer in the gas phase.^[3] In the gas phase it adopts D_3h symmetric trigonal bipyramidal geometry as indicated by electron diffraction.^[4] As a solid, VF₅ forms a polymeric structure with fluoride-bridged octahedral vanadium centers.^[3]^[5]

The formation enthalpy of VF₅ is -1429.4 ± 0.8 kJ/mol.^[6]

It is the only known pentahalide of vanadium.

Synthesis

Vanadium pentafluoride can be prepared by fluorination of vanadium metal:^[7]^[1]

2 V + 5 F₂ → 2 VF₅

Alternatively, disproportionation of vanadium tetrafluoride yields equal amounts of the solid trifluoride and the volatile pentafluoride:^[8]^[9]^[1]

2 VF₄ → VF₃ + VF₅

This conversion is conducted at 650 °C. It can also be synthesized by using elemental fluorine to fluorinate industrial concentrates and raw materials so as to produce VF₅ on an industrial scale. VF₅ can be synthesized from the reaction of raw materials such as metallic Vanadium, ferrovanadium, vanadium (V) oxide and vanadium tetrafluoride with elemental fluorine.^[10]

VF₅ ionises in the liquid state as reflected by the high values of Trouton's constant and electrical conductivities.^[11]

Characteristics and reactivity

Interest in this highly corrosive compound began in the fifties when there were extensive studies of its physicochemical properties.^[10] It is a powerful fluorinating and oxidizing agent. It oxidizes elemental sulfur to sulfur tetrafluoride:.

S + 4 VF₅ → 4 VF₄ + SF₄

Like other electrophilic metal halides, it hydrolyzes, first to the oxyhalide:

VF₅ + H₂O → VOF₃ + 2 HF

Then to the binary oxide:

2 VOF₃ + 3 H₂O → V₂O₅ + 6 HF

Hydrolysis is accelerated in the presence of base. Despite its tendency to hydrolyze, it can be dissolved in alcohols.

It is a Lewis acid, as illustrated by its formation of the hexafluorovanadate:^[12]^[13]^[14]

VF₅ + KF → KVF₆

Vanadium pentafluoride is a weaker acid and mainly undergoes oxidative and fluorinating reactions.^[15]

The compound fluorinates unsaturated polyfluoroolefins into polyfluoroalkanes.^[10]

The compound dissolves without reaction in liquid Cl₂ and Br₂. VF₅ is moderately soluble in HF.

Related Research Articles

Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colorless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material PTFE (Teflon). Elemental fluorine is produced from it. It is commonly used to etch glass and silicon wafers.

<span class="mw-page-title-main">Nickel(II) fluoride</span> Chemical compound

Nickel(II) fluoride is the chemical compound with the formula NiF₂. It is an ionic compound of nickel and fluorine and forms yellowish to green tetragonal crystals. Unlike many fluorides, NiF₂ is stable in air.

Xenon tetrafluoride is a chemical compound with chemical formula XeF^₄. It was the first discovered binary compound of a noble gas. It is produced by the chemical reaction of xenon with fluorine:

<span class="mw-page-title-main">Silver(II) fluoride</span> Chemical compound

Silver(II) fluoride is a chemical compound with the formula AgF₂. It is a rare example of a silver(II) compound - silver usually exists in its +1 oxidation state. It is used as a fluorinating agent.

<span class="mw-page-title-main">Sulfur tetrafluoride</span> Chemical compound

Sulfur tetrafluoride is the chemical compound with the formula SF₄. It is a colorless corrosive gas that releases dangerous HF upon exposure to water or moisture. Despite these unwelcome characteristics, this compound is a useful reagent for the preparation of organofluorine compounds, some of which are important in the pharmaceutical and specialty chemical industries.

<span class="mw-page-title-main">Selenium tetrafluoride</span> Chemical compound

Selenium tetrafluoride (SeF₄) is an inorganic compound. It is a colourless liquid that reacts readily with water. It can be used as a fluorinating reagent in organic syntheses (fluorination of alcohols, carboxylic acids or carbonyl compounds) and has advantages over sulfur tetrafluoride in that milder conditions can be employed and it is a liquid rather than a gas.

Vanadium(IV) fluoride (VF₄) is an inorganic compound of vanadium and fluorine. It is paramagnetic yellow-brown solid that is very hygroscopic. Unlike the corresponding vanadium tetrachloride, the tetrafluoride is not volatile because it adopts a polymeric structure. It decomposes before melting.

<span class="mw-page-title-main">Xenon oxytetrafluoride</span> Chemical compound

Xenon oxytetrafluoride is an inorganic chemical compound. It is an unstable colorless liquid with a melting point of −46.2 °C that can be synthesized by partial hydrolysis of XeF^₆, or the reaction of XeF^₆ with silica or NaNO^₃:

Tungsten oxytetrafluoride is an inorganic compound with the formula WOF₄. It is a colorless diamagnetic solid. The compound is one of many oxides of tungsten. It is usually encountered as product of the partial hydrolysis of tungsten hexafluoride.

<span class="mw-page-title-main">Dioxygenyl</span> Chemical compound

The dioxygenyl(or dioxyl) ion, O⁺
₂, is a rarely-encountered oxycation in which both oxygen atoms have a formal oxidation state of $+ 1 / 2$ . It is formally derived from oxygen by the removal of an electron:

<span class="mw-page-title-main">Manganese(IV) fluoride</span> Chemical compound

Manganese tetrafluoride, MnF₄, is the highest fluoride of manganese. It is a powerful oxidizing agent and is used as a means of purifying elemental fluorine.

Arsenic pentafluoride is a chemical compound of arsenic and fluorine. It is a toxic, colorless gas. The oxidation state of arsenic is +5.

<span class="mw-page-title-main">Thionyl tetrafluoride</span> Chemical compound

Thionyl tetrafluoride, also known as sulfur tetrafluoride oxide, is an inorganic compound with the formula SOF₄. It is a colorless gas.

<span class="mw-page-title-main">Chromyl fluoride</span> Chemical compound

Chromyl fluoride is an inorganic compound with the formula CrO₂F₂. It is a violet-red colored crystalline solid that melts to an orange-red liquid.

Chromium pentafluoride is the inorganic compound with the chemical formula CrF₅. It is a red volatile solid that melts at 34 °C. It is the highest known chromium fluoride, since the hypothetical chromium hexafluoride has not yet been synthesized.

Neptunium(VI) fluoride (NpF₆) is the highest fluoride of neptunium, it is also one of seventeen known binary hexafluorides. It is an orange volatile crystalline solid. It is relatively hard to handle, being very corrosive, volatile and radioactive. Neptunium hexafluoride is stable in dry air but reacts vigorously with water.

Fluorine forms a great variety of chemical compounds, within which it always adopts an oxidation state of −1. With other atoms, fluorine forms either polar covalent bonds or ionic bonds. Most frequently, covalent bonds involving fluorine atoms are single bonds, although at least two examples of a higher order bond exist. Fluoride may act as a bridging ligand between two metals in some complex molecules. Molecules containing fluorine may also exhibit hydrogen bonding. Fluorine's chemistry includes inorganic compounds formed with hydrogen, metals, nonmetals, and even noble gases; as well as a diverse set of organic compounds. For many elements the highest known oxidation state can be achieved in a fluoride. For some elements this is achieved exclusively in a fluoride, for others exclusively in an oxide; and for still others the highest oxidation states of oxides and fluorides are always equal.

<span class="mw-page-title-main">Trifluoramine oxide</span> Chemical compound

Trifluoramine oxide or Nitrogen trifluoride oxide (F₃NO) is an inorganic molecule with strong fluorinating powers.

The hexafluoroarsenate anion is a chemical species with formula AsF−6. Hexafluoroarsenate is relatively inert, being the conjugate base of the notional superacid hexafluoroarsenic acid.

<span class="mw-page-title-main">Iodyl fluoride</span> Chemical compound

Iodyl fluoride is an inorganic compound of iodine, fluorine, and oxygen with the chemical formula IO₂F. The compound was initially synthesized in 1951.

References

1 2 3 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 989. ISBN 978-0-08-037941-8.
↑ Canterford, J. H.; O'Donnell, Thomas A. (1967-03-01). "Reactivity of transition metal fluorides. IV. Oxidation-reduction reactions of vanadium pentafluoride". Inorganic Chemistry. 6 (3): 541–544. doi:10.1021/ic50049a025. ISSN 0020-1669.
1 2 Brownstein, S.; Latremouille, G. (1974-06-15). "Complex Fluoroanions in Solution. V. Vanadium Pentafluoride". Canadian Journal of Chemistry. 52 (12): 2236–2241. doi: 10.1139/v74-323 . ISSN 0008-4042.
↑ Hagen, Kolbjoern.; Gilbert, Michael M.; Hedberg, Lise.; Hedberg, Kenneth. (1982-07-01). "Molecular structure of gaseous vanadium pentafluoride, VF5". Inorganic Chemistry. 21 (7): 2690–2693. doi:10.1021/ic00137a031. ISSN 0020-1669.
↑ Brownstein, S. (1980-06-01). "The structure of VF5 in solution". Journal of Fluorine Chemistry. 15 (6): 539–540. doi:10.1016/S0022-1139(00)85231-8.
↑ Nikitin, M. I.; Zbezhneva, S. G. (2014-12-16). "Thermochemistry of vanadium fluorides: The formation enthalpies of vanadium fluorides". High Temperature. 52 (6): 809–813. doi:10.1134/S0018151X14060108. ISSN 0018-151X. S2CID 98343689.
↑ Trevorrow, L. E.; Fischer, J.; Steunenberg, R. K. (1957). "The Preparation and Properties of Vanadium Pentafluoride". Journal of the American Chemical Society. 79 (19): 5167–5168. doi:10.1021/ja01576a023.
↑ Ruff, Otto; Lickfett, Herbert (1911). "Vanadinfluoride". Berichte der Deutschen Chemischen Gesellschaft. 44 (3): 2539–2549. doi:10.1002/cber.19110440379.
↑ Cavell, R. G.; Clark, H. C. (1963). "Thermochemistry of vanadium fluorides". Transactions of the Faraday Society. 59: 2706. doi:10.1039/TF9635902706.
1 2 3 Krasil'nikov, V. A.; Andreev, G. G.; Karelin, A. I.; Guzeeva, T. I.; Furin, G. G.; Bardin, V. V.; Avramenko, A. A. (1995-10-17). "ChemInform Abstract: Synthesis and Use of Vanadium Pentafluoride". ChemInform. 26 (42): no. doi:10.1002/chin.199542022. ISSN 1522-2667.
↑ Clark, H. C.; Emeléus, H. J. (January 1958). "40. Chemical reactions with vanadium, niobium, and tantalum pentafluorides". J. Chem. Soc.: 190–195. doi:10.1039/jr9580000190.
↑ Nikolsky, B. P. [Никольский, Б.П.] et al, eds. (1971). Справочник химика [The Chemist's Handbook] (in Russian). 3^rd (corrected) ed. Leningrad: Khimiya.
↑ Knunyants, I. L. [Кнунянц, И.Л.] et al, eds. (1995). Химическая энциклопедия [A Chemical Encyclopedia] (in Russian). Moscow: Soviet Encyclopedias. ISBN 978-5-85270-092-6
↑ Lidin, R. A. [Лидин Р.А.] et al (2000). Химические свойства неорганических веществ: Учеб. пособие для вузов [Chemical Properties of Inorganic Substances: A University Textbook] (in Russian). 3^rd (corrected) ed. Мoscow: Khimiya. ISBN 978-5-7245-1163-6
↑ Fowler, Brian R.; Moss, Kenneth C. (1979-12-01). "An N.M.R. study of the solution chemistry of vanadium pentafluoride". Journal of Fluorine Chemistry. 14 (6): 485–494. doi:10.1016/S0022-1139(00)82524-5.