Vanadyl(IV) sulfate describes a collection of

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 chemis ...

s of vanadium with the formula, VOSO₄(H₂O)_x where 0 ≤ x ≤ 6. The pentahydrate is common. This hygroscopic blue solid 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". Vanadyl sulfate is an intermediate in the extraction of vanadium from petroleum residues, one commercial source of vanadium.

Synthesis, structure, and reactions

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

sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic a ...

: :V₂O₅ + 7 H₂O + SO₂ + H₂SO₄ → 2 (O)(H₂O)₄O₄ 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 A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as '' ligands'' or complexing agents. M ...

, the ion is octahedral, with oxo, four equatorial water ligands, and a monodentate sulfate. The trihydrate has also been examined by crystallography. A hexahydrate exists below . Two polymorphs of anhydrous VOSO₄ are known. 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: : (O)(H₂O)₄O₄ + 2 C₅H₈O₂ + Na₂CO₃ → (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 Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

, 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, a mineral of

fumarolic A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volc ...

origin. Hydrated forms, also rare, include hexahydrate (stanleyite), pentahydrates (minasragrite, orthominasragrite, and anorthominasragrite) and trihydrate - bobjonesite.

Medical research

Vanadyl sulfate is a component of food supplements and experimental drugs. Vanadyl sulfate exhibits insulin-like effects. Vanadyl sulfate has been extensively studied in the field of

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...

research as a potential means of increasing

insulin Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the ''INS'' gene. It is considered to be the main anabolic hormone of the body. It regulates the metabolism ...

sensitivity. No evidence indicates that oral vanadium supplementation improves glycaemic control. Treatment with vanadium often results in gastrointestinal side-effects, primarily

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...

. Vanadyl sulfate is also marketed as a health supplement, often for

bodybuilding Bodybuilding is the use of progressive resistance exercise to control and develop one's muscles (muscle building) by muscle hypertrophy for aesthetic purposes. It is distinct from similar activities such as powerlifting because it focuses ...

. Deficiencies in vanadium result in reduced growth in rats. Its effectiveness for bodybuilding has not been proven; some evidence suggests that athletes who take it are merely experiencing a placebo effect.

References

{{Sulfates Vanadium(IV) compounds Sulfates Vanadyl compounds