Vanadyl sulfate

Vanadyl(IV) sulfate describes a collection of inorganic compounds of vanadium with the formula, VOSO₄(H₂O)_x where 0 ≤ x ≤ 6. The pentahydrate is common. This hygroscopic blue salt is one of the most common sources of vanadium in the laboratory, reflecting its high stability. It features the vanadyl ion, VO²⁺, which has been called the "most stable diatomic ion".^[1]

Vanadyl sulfate

Vanadyl sulfate
Names
IUPAC name Oxovanadium(2+) sulfate
Other names Basic vanadium(IV) sulfate Vanadium(IV) oxide sulfate Vanadium(IV) oxysulfate
Identifiers
CAS Number	Anhydrous: 27774-13-6 Y Pentahydrate: 12439-96-2
3D model (JSmol)	Anhydrous: Interactive image Pentahydrate: Interactive image
ChemSpider	Anhydrous: 31347 N Pentahydrate: 146243
ECHA InfoCard	100.044.214
PubChem CID	Anhydrous: 34007 Pentahydrate: 167150
RTECS number	Anhydrous: YW1925000
UNII	Anhydrous: 6DU9Y533FA Y
CompTox Dashboard (EPA)	Anhydrous: DTXSID4021428
InChI InChI=1S/H2O4S.O.V/c1-5(2,3)4;;/h(H2,1,2,3,4);;/q;;+2/p-2 N Key: UUUGYDOQQLOJQA-UHFFFAOYSA-L N Pentahydrate: InChI=1S/H2O4S.5H2O.O.V/c1-5(2,3)4;;;;;;;/h(H2,1,2,3,4);5*1H2;;/q;;;;;;;+2/p-2 Key: YGYBXHQARYQUAY-UHFFFAOYSA-L
SMILES Anhydrous: O=S(=O)([O-])[O-].O=[V+2] Pentahydrate: O.O.O.O.O.O=S(=O)([O-])[O-].O=[V+2]
Properties
Chemical formula	H10O10SV
Molar mass	253.07 g·mol−1
Appearance	Blue solid
Melting point	105 °C (221 °F; 378 K) decomposes
Solubility in water	Soluble
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Irritant
Flash point	Non-flammble
Related compounds
Other anions	Vanadyl chloride Vanadyl nitrate
Other cations	Vanadium(III) sulfate
Related compounds	Vanadyl acetylacetonate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Vanadyl sulfate trihydrate

Vanadyl sulfate is an intermediate in the extraction of vanadium from petroleum residues, one commercial source of vanadium.^[2]

Synthesis, structure, and reactions

Vanadyl sulfate is most commonly obtained by reduction of vanadium pentoxide with sulfur dioxide:

V₂O₅ + 7 H₂O + SO₂ + H₂SO₄ → 2 [V(O)(H₂O)₄]SO₄

From aqueous solution, the salt crystallizes as the pentahydrate, the fifth water is not bound to the metal in the solid. Viewed as a coordination complex, the ion is octahedral, with oxo, four equatorial water ligands, and a monodentate sulfate.^[1][3] The trihydrate has also been examined by crystallography.^[4] A hexahydrate exists below 13.6 °C (286.8 K).^[5] Two polymorphs of anhydrous VOSO₄ are known.^[6]

The V=O bond distance is 160 pm, about 50 pm shorter than the V–OH₂ bonds. In solution, the sulfate ion dissociates rapidly.

Being widely available, vanadyl sulfate is a common precursor to other vanadyl derivatives, such as vanadyl acetylacetonate:^[7]

[V(O)(H₂O)₄]SO₄ + 2 C₅H₈O₂ + Na₂CO₃ → [V(O)(C₅H₇O₂)₂] + Na₂SO₄ + 5 H₂O + CO₂

In acidic solution, oxidation of vanadyl sulfate gives yellow-coloured vanadyl(V) derivatives. Reduction, e.g. by zinc, gives vanadium(III) and vanadium(II) derivatives, which are characteristically green and violet, respectively.

Occurrence in nature

Like most water-soluble sulfates, vanadyl sulfate is only rarely found in nature. Anhydrous form is pauflerite,^[8] a mineral of fumarolic origin. Hydrated forms, also rare, include hexahydrate (stanleyite), pentahydrates (minasragrite, orthominasragrite,^[9] and anorthominasragrite) and trihydrate - bobjonesite.^[10]

Medical research

Vanadyl sulfate is a component of food supplements and experimental drugs. Vanadyl sulfate exhibits insulin-like effects.^[11]

Vanadyl sulfate has been extensively studied in the field of diabetes research as a potential means of increasing insulin sensitivity. No evidence indicates that oral vanadium supplementation improves glycaemic control.^[12][13] Treatment with vanadium often results in gastrointestinal side-effects, primarily diarrhea.

Vanadyl sulfate is also marketed as a health supplement, often for bodybuilding. Deficiencies in vanadium result in reduced growth in rats.^[14] Its effectiveness for bodybuilding has not been proven; some evidence suggests that athletes who take it are merely experiencing a placebo effect.^[15]