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| Names | |
|---|---|
| Other names Tungsten dioxide | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider | |
| ECHA InfoCard | 100.031.662 |
| EC Number |
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| UNII | |
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| Properties | |
| WO2 | |
| Molar mass | 215.839 g/mol |
| Appearance | Bronze solid |
| Density | 10.8 g/cm3 |
| Melting point | 1,474 °C (2,685 °F; 1,747 K) from doi: 10.1007/BF02877593, decomposes at 1700 ◦C |
| Negligible | |
| 5.7×10−5 cm3/mol | |
| Structure | |
| Distortedrutile (monoclinic),mP12, space group P21/c, no 14 | |
| Hazards | |
| Flash point | Non-flammable |
| Related compounds | |
Otheranions | Tungsten disulfide |
Othercations | Chromium(IV) oxide Molybdenum(IV) oxide |
| Tungsten(III) oxide Tungsten(VI) oxide | |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Tungsten(IV) oxide is thechemical compound with theformulaWO2. The bronze-colored solid crystallizes in amonoclinic cell.[1] Therutile-like structure features distorted octahedral WO6 centers with alternate short W–W bonds (248 pm).[1] Each tungsten center has the d2 configuration, which gives the material a highelectrical conductivity.
WO2 is prepared by reduction ofWO3 with tungsten powder over the course of 40 hours at 900 °C. An intermediate in this reaction is the partially reduced, mixed valence speciesW18O49.
Themolybdenum analogueMoO2 is prepared similarly. Single crystals are obtained bychemical transport technique usingiodine. Iodine transports the WO2 in the form of the volatile species WO2I2.[2][3]
