Vanadium(V) fluoride is the

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...

with the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...

VF₅. It is a colorless volatile liquid. It is a highly reactive compound, as indicated by its ability to fluorinate

organic Organic may refer to: * Organic, of or relating to an organism, a living entity * Organic, of or relating to an anatomical organ Chemistry * Organic matter, matter that has come from a once-living organism, is capable of decay or is the product ...

substances.

Properties and structure

The compound is exclusively a

monomer In chemistry, a monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Classification Mo ...

in the gas phase. In the gas phase it adopts D_3h symmetric

trigonal bipyramidal In chemistry, a trigonal bipyramid formation is a molecular geometry with one atom at the center and 5 more atoms at the corners of a triangular bipyramid. This is one geometry for which the bond angles surrounding the central atom are not identi ...

geometry as indicated by

electron diffraction Electron diffraction refers to the bending of electron beams around atomic structures. This behaviour, typical for waves, is applicable to electrons due to the wave–particle duality stating that electrons behave as both particles and waves. Si ...

. As a solid, VF₅ forms a polymeric structure with fluoride-bridged

octahedral In geometry, an octahedron (plural: octahedra, octahedrons) is a polyhedron with eight faces. The term is most commonly used to refer to the regular octahedron, a Platonic solid composed of eight equilateral triangles, four of which meet at ea ...

vanadium centers. The

formation enthalpy In chemistry and thermodynamics, the standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements in their reference state, with ...

of VF₅ is -1429.4 ± 0.8 kJ/mol. It is the only known pentahalide of vanadium.

Synthesis

Vanadium pentafluoride can be prepared by

fluorination In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, ...

of vanadium metal: : 2 V + 5 F₂ → 2 VF₅ Alternatively,

disproportionation In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation states. More generally, the term can b ...

vanadium tetrafluoride Vanadium(IV) fluoride (Vanadium, VFluorine, F4) 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 b ...

yields equal amounts of the solid trifluoride and the volatile pentafluoride: :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 Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer ( pas ...

ferrovanadium Ferrovanadium (FeV) is an alloy formed by combining iron and vanadium with a vanadium content range of 35–85%. The production of this alloy results in a grayish silver crystalline solid that can be crushed into a powder called "ferrovanadium ...

vanadium (V) oxide Vanadium(V) oxide (''vanadia'') is the inorganic compound with the formula V2 O5. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because ...

and

with elemental

fluorine Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reacti ...

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

Characteristics and Reactivity

Interest in this highly

corrosive A corrosive substance is one that will damage or destroy other substances with which it comes into contact by means of a chemical reaction. Etymology The word ''corrosive'' is derived from the Latin verb ''corrodere'', which means ''to gnaw'', ...

compound began in the fifties when there were extensive studies of its

physicochemical Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mecha ...

properties. It is a powerful fluorinating and oxidizing agent. It oxidizes elemental sulfur to

sulfur tetrafluoride Sulfur tetrafluoride is the chemical compound with the formula S F4. 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 t ...

:. :S + 4 VF₅ → 4 VF₄ + SF₄ Like other electrophilic metal halides, it hydrolyzes, first to the

oxyhalide In chemistry, molecular oxohalides (oxyhalides) are a group of chemical compounds in which both oxygen and halogen atoms are attached to another chemical element A in a single molecule. They have the general formula , where X = fluorine (F), chlor ...

: :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 A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...

, as illustrated by its formation of the hexafluorovanadate: :VF₅ + KF → KVF₆ Vanadium pentafluoride is a weaker acid and mainly undergoes oxidative and fluorinating reactions. The compound fluorinates unsaturated polyfluoro

olefins In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, an ...

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

Properties and structure

Synthesis

Characteristics and Reactivity

References

Other reading