The vanadyl or oxovanadium(IV)

cation An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

, VO²⁺, is a

functional group In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest ...

that is common in the

coordination chemistry 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. Many ...

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 ...

. Complexes containing this functional group are characteristically blue and paramagnetic. A triple bond is proposed to exist between the V⁴⁺ and O²⁻ centers. The description of the bonding in the vanadyl ion was central to the development of modern

ligand-field theory Ligand field theory (LFT) describes the bonding, orbital arrangement, and other characteristics of coordination complexes. It represents an application of molecular orbital theory to transition metal complexes. A transition metal ion has nine vale ...

Natural occurrence

Minerals

Cavansite Cavansite, whose name is derived from its chemical composition, ''calcium vanadium silicate'', is a deep blue hydrous calcium vanadium phyllosilicate mineral, occurring as a secondary mineral in basaltic and andesitic rocks along with a variety o ...

and

pentagonite Pentagonite is a rare silicate mineral with formula Ca(VO)Si4O10·4(H2O). It was named for the unusual twinning which produces an apparent five-fold symmetry. It is a dimorph of cavansite. Pentagonite was first described in 1973 for an occurre ...

are vanadyl-containing minerals.

Water

VO²⁺, often in an ionic pairing with sodium (NaH₂VO₄), is the second most abundant

transition metal In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. They are the elements that can ...

seawater Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appro ...

, with its concentration only being exceeded by

molybdenum Molybdenum is a chemical element with the symbol Mo and atomic number 42 which is located in period 5 and group 6. The name is from Neo-Latin ''molybdaenum'', which is based on Ancient Greek ', meaning lead, since its ores were confused with lea ...

. In the ocean the average concentration is 30 nM. Some

mineral water Mineral water is water from a mineral spring that contains various minerals, such as salts and sulfur compounds. Mineral water may usually be still or sparkling (carbonated/effervescent) according to the presence or absence of added gases. T ...

springs also contain the ion in high concentrations. For example, springs near

Mount Fuji , or Fugaku, located on the island of Honshū, is the highest mountain in Japan, with a summit elevation of . It is the second-highest volcano located on an island in Asia (after Mount Kerinci on the island of Sumatra), and seventh-highest p ...

often contain as much as 54 μg per liter.

Vanadyl containing compounds

Oxovanadium(IV)

vanadyl acetylacetonate Vanadyl acetylacetonate is the chemical compound with the formula VO(acac)2, where acac– is the conjugate base of acetylacetone. It is a blue-green solid that dissolves in polar organic solvents. The coordination complex consists of the vanadyl ...

, VO(acac)₂ * vanadyl sulfate pentahydrate, VOSO₄·5H₂O

Oxovanadium(V)

vanadyl isopropoxide Vanadyl isopropoxide is the metal alkoxide with the formula VO(O-iPr)3 (iPr = CH(CH3)2). A yellow volatile liquid, it is a common alkoxide of vanadium. It is used as a reagent and as a precursor to vanadium oxides. The compound is diamagnetic. It ...

, VO(O-iPr)₃ (iPr denotes

isopropyl In organic chemistry, propyl is a three-carbon alkyl substituent with chemical formula for the linear form. This substituent form is obtained by removing one hydrogen atom attached to the terminal carbon of propane. A propyl substituent is ofte ...

) *

vanadyl nitrate Vanadyl nitrate, also called vanadium oxytrinitrate or vanadium oxynitrate is an inorganic compound of vanadium in the +5 oxidation state with nitrate ligands and oxygen. The formula is VO(NO3)3. It is a pale yellow viscous liquid. Production It ...

, VO(NO₃)₃ *

vanadyl perchlorate Vanadyl perchlorate or vanadyl triperchlorate is a golden yellow coloured liquid or crystalline compound of vanadium, oxygen and perchlorate group. The substance consists of molecules covalently bound and is quite volatile. Formation Vanadyl perc ...

Related species

pervanadyl Pervanadyl () is a pale yellow oxycation of vanadium(V). It is the predominant vanadium(V) species in acidic solutions with pH between 0 and 2, and its salts are formed by protonation of vanadium(V) oxide in such solutions: : ('' K'' =&nbs ...

ion, , also known as the dioxovanadium(V) ion * metavanadate ion, *

orthovanadate In chemistry, a vanadate is an anionic coordination complex of vanadium. Often vanadate refers to oxoanions of vanadium, most of which exist in its highest oxidation state of +5. The complexes and are referred to as hexacyanovanadate(III) and no ...

ion, * thiovanadyl ion, VS²⁺ *

titanyl In inorganic chemistry, titanyl refers to the functional group TiIVO, sometimes written TiO2+. The term titanyl is used loosely to describe many titanium(IV) oxide compounds and complexes. For example, titanyl sulfate and potassium titanyl phospha ...

ion, TiO²⁺ * niobyl ion, NbO²⁺ * tantalyl ion, TaO²⁺

References

External links

*{{Commonscatinline, Vanadyl ion Oxycations