:Vanadium(II) oxide

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| Watchedfields = changed

| verifiedrevid = 445720257

| ImageFile = Vanadium(II)-oxide-3D-vdW.png

| ImageSize = 180px

| IUPACName = Vanadium(II) oxide

| OtherNames = Vanadium oxide

|Section1={{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 12035-98-2

| PubChem = 24411

| SMILES = [V+2].[O-2]

| RTECS =

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|Section2={{Chembox Properties

| Formula = VO

| MolarMass = 66.9409 g/mol

| Appearance = grey solid with metallic lustre

| Density = 5.758 g/cm³

| Solubility =

| MeltingPtC = 1789

| MeltingPt_notes =

| BoilingPtC = 2627

| BoilingPt_notes =

| pKa =

| pKb =

| RefractIndex = 1.5763

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|Section3={{Chembox Structure

| CrystalStruct = Halite (cubic), cF8

| SpaceGroup = Fm3m, No. 225

| Coordination = Octahedral (V²⁺)
Octahedral (O²⁻)

| LattConst_a =

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| Section4 = {{Chembox Thermochemistry

| DeltaGf = −404.219 kJ/molR. Robie, B. Hemingway, and J. Fisher, “Thermodynamic Properties of Minerals and Related Substances at 298.15K and 1bar Pressure and at Higher Temperatures,” US Geol. Surv., vol. 1452, 1978.

| DeltaHc =

| DeltaHf = −431.790 kJ/mol

| Entropy = 39.01 J/mol·K

| HeatCapacity =

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|Section7={{Chembox Hazards

| ExternalSDS =

| HPhrases =

| PPhrases =

| GHS_ref =

| MainHazards =

| NFPA-H =

| NFPA-F =

| NFPA-R =

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| FlashPt = Non-flammable

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|Section8={{Chembox Related

| OtherAnions = Vanadium monosulfide
Vanadium monoselenide
Vanadium monotelluride

| OtherCations = Niobium(II) oxide
Tantalum(II) oxide

| OtherFunction = Vanadium(III) oxide
Vanadium(IV) oxide
Vanadium(V) oxide

| OtherFunction_label = vanadium oxides

| OtherCompounds =

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Vanadium(II) oxide is the inorganic compound with the idealized formula VO. It is one of the several binary vanadium oxides. It adopts a distorted NaCl structure and contains weak V−V metal to metal bonds. VO is a semiconductor owing to delocalisation of electrons in the t_2g orbitals. VO is a non-stoichiometric compound, its composition varying from VO_0.8 to VO_1.3.{{Greenwood&Earnshaw2nd|page=982}}

Diatomic VO is one of the molecules found in the spectrum of relatively cool M-type stars.{{cite journal| last = Tsuji| first = T.| date = 1986| title = Molecules in Stars.| journal = Annu. Rev. Astron. Astrophys.| volume = 24| page = 94| bibcode = 1986ARA&A..24...89T| doi = 10.1146/annurev.aa.24.090186.000513}} A potential use of vanadium(II) monoxide is as a molecular vapor in synthetic chemical reagents in low-temperature matrices.{{Cite journal |last=Groshens |first=Thomas J. |last2=Klabunde |first2=Kenneth J. |date=August 1990 |title=Molecular vapor synthesis: the use of titanium monoxide and vanadium monoxide vapors as reagents |url=https://pubs.acs.org/doi/abs/10.1021/ic00341a025 |journal=Inorganic Chemistry |language=en |volume=29 |issue=16 |pages=2979–2982 |doi=10.1021/ic00341a025 |issn=0020-1669}}