Vanadyl ion

{{short description|Polyatomic ion in chemistry}} {{distinguish||text=the pervanadyl ion, with the formula {{chem|VO|2|+}}}} [[File:Vo(acac)2.png|thumb|right|Structure of vanadyl acetylacetonate]] [[Image:Cavansite.jpg|thumb|right|Cavansite, a mineral containing the vanadyl cation that illustrates its characteristic color]] The '''vanadyl ion''' is an oxovanadium cation, either VO²⁺ (called ''oxovanadium(IV)'')<ref name="Bertrand">{{cite journal|last1=Bertrand|first1=Gary L.|last2=Stapleton|first2=George W.|last3=Wulff|first3=Clause A.|last4=Hepler|first4=Loren G.|title=Thermochemistry of Aqueous Pervanadyl and Vanadyl Ions|journal=Inorg. Chem.|date=July 1966|volume=5|issue=7|pages=1283–1284|doi=10.1021/ic50041a048}}</ref> or VO³⁺ (called ''oxovanadium(V)''). They are functional groups that are common in the coordination chemistry of vanadium.

Complexes containing oxovanadium(IV) are characteristically blue or purple<ref>{{cite journal|last1=Bellhausen|first1=C.J.|last2=Gray|first2=Harry B.|title=The Electronic Structure of the Vanadyl Ion|journal=Inorganic Chemistry|volume=1|issue=1|year=1962|pages=111-122|doi=10.1021/ic50001a022}}</ref> and paramagnetic.<ref>{{cite journal|last1=Smith|first1=Thomas S. II|last2=LoBrutto|first2=Russell|last3=Pecoraro|first3=Vincent L.|title=Paramagnetic spectroscopy of vanadyl compounds and its applications to biological systems|journal=Coordination Chemistry Reviews|volume=228|issue=1|year=2002|pages=1-18|doi=10.1016/S0010-8545(01)00437-4|url=https://www1.udel.edu/chem/polenova/VHPO/Vanayl_complexes_Paramagn_spectr_CoordChemRev2002.pdf|access-date=12 November 2025|via=University of Delaware}}</ref> A triple bond is proposed to exist between the V⁴⁺ and O²⁻ centers.<ref>{{cite journal|author1=Gray, H. B. |author2=Winkler, J. R. |title=Living with Oxygen|journal=Accounts of Chemical Research|year=2018|volume=51|issue=8|pages=1850–1857|doi=10.1021/acs.accounts.8b00245|pmid=30016077|pmc=6106048}}</ref> The description of the bonding in the vanadyl ion was central to the development of modern ligand-field theory.<ref>{{Cite journal|last=Ballhausen|first=C. J.|last2=Gray|first2=Harry B.|date=1962-02-01|title=The Electronic Structure of the Vanadyl Ion|url=https://doi.org/10.1021/ic50001a022|journal=Inorganic Chemistry|volume=1|issue=1|pages=111–122|doi=10.1021/ic50001a022|issn=0020-1669|url-access=subscription}}</ref>

==Natural occurrence== ===Minerals=== Cavansite and pentagonite are vanadyl-containing minerals.{{citation needed|date=November 2025}}

===Water=== VO²⁺, often in an ionic pairing with sodium (NaH₂VO₄), is the second most abundant transition metal in seawater, with its concentration only being exceeded by molybdenum.<ref name=Dieter>{{cite book|last1=Rehder|first1=Dieter|title=Bioinorganic Vanadium Chemistry|date=2008|publisher=John Wiley & Sons, Ltd|location=Hamburg, Germany|isbn=9780470065099|pages=5 & 9–10|edition=1st|doi=10.1002/9780470994429|series=Inorganic Chemistry}}</ref> In the ocean the average concentration is 30&nbsp;nM. Some mineral water springs also contain the ion in high concentrations. For example, springs near Mount Fuji often contain as much as 54&nbsp;μg per liter.<ref name=Dieter />

==Vanadyl-containing compounds == === Oxovanadium(IV) === * vanadyl acetylacetonate, VO(acac)₂ * vanadyl sulfate, VOSO₄ * vanadyl acetate, VO(CH₃COO)₂

=== Oxovanadium(V) === * vanadyl isopropoxide, VO(O-iPr)₃ (iPr denotes isopropyl) * vanadyl nitrate, VO(NO₃)₃<ref>{{cite journal|last1=Varetti|first1=E.L.|last2=Brandán|first2=S.A.|last3=Ben Altabef|first3=A.|title=Vibrational and electronic spectra of vanadyl nitrate, VO(NO₃)₃|journal=Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy|date=April 1995|volume=51|issue=4|pages=669–675|doi=10.1016/0584-8539(94)00154-4|bibcode=1995AcSpA..51..669B}}</ref> * vanadyl perchlorate, {{chem2|VO(ClO4)3}} * vanadyl fluoride, {{chem2|VOF3}} * vanadyl chloride, {{chem2|VOCl3}}

==Related species== * pervanadyl ion, {{chem|VO|2|+}},<ref name="Bertrand" /><ref>{{cite journal|last1=Satyanarayan|first1=Pal|last2=Kasiraman|first2=Rinku Radhika|title=Mononuclear Pervanadyl ({{chem|VO|2|+}}) Complexes with Tridentate Schiff Bases: Self-assembling via C–H…oxo and π-π Interactions|journal=Zeitschrift für Anorganische und Allgemeine Chemie|date=July 2001|volume=627|issue=7|pages=1631–1637|doi=10.1002/1521-3749(200107)627:7<1631::AID-ZAAC1631>3.0.CO;2-H}}</ref> also known as the dioxovanadium(V) ion * metavanadate ion, {{chem|[VO|3|]|''n''|''n''−}} * orthovanadate ion, {{chem|VO|4|3−}} * thiovanadyl ion, VS²⁺ * titanyl ion, TiO²⁺ * niobyl ion, NbO²⁺ * tantalyl ion, TaO²⁺

==References== {{Reflist}}

== General references == {{Commonscat|Vanadyl ion}} * {{Greenwood&Earnshaw}}

{{Vanadium compounds}}

Category:Oxycations Category:Vanadyl compounds