Vanadium(II) oxide
| Names | |
|---|---|
| IUPAC name Vanadium(II) oxide | |
| Other names Vanadium oxide | |
| Identifiers | |
| 3D model (JSmol) | |
| ECHA InfoCard | 100.031.655 | 
| PubChem CID | |
| CompTox Dashboard (EPA) | |
| 
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| Properties | |
| VO | |
| Molar mass | 66.9409 g/mol | 
| Appearance | grey solid with metallic lustre | 
| Density | 5.758 g/cm3 | 
| Melting point | 1,789 °C (3,252 °F; 2,062 K) | 
| Boiling point | 2,627 °C (4,761 °F; 2,900 K) | 
| Refractive index (nD) | 1.5763 | 
| Structure | |
| Halite (cubic), cF8 | |
| Fm3m, No. 225 | |
| Octahedral (V2+) Octahedral (O2−) | |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 39.01 J/mol·K | 
| Std enthalpy of formation (ΔfH⦵298) | −431.790 kJ/mol | 
| Gibbs free energy (ΔfG⦵) | −404.219 kJ/mol | 
| Hazards | |
| Flash point | Non-flammable | 
| Related compounds | |
| Other anions | Vanadium monosulfide Vanadium monoselenide Vanadium monotelluride | 
| Other cations | Niobium(II) oxide Tantalum(II) oxide | 
| Vanadium(III) oxide Vanadium(IV) oxide Vanadium(V) oxide | |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references | |
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 t2g orbitals. VO is a non-stoichiometric compound, its composition varying from VO0.8 to VO1.3.
Diatomic VO is one of the molecules found in the spectrum of relatively cool M-type stars. A potential use of vanadium(II) monoxide is as a molecular vapor in synthetic chemical reagents in low-temperature matrices.