|   | |
|   | |
| Names | |
|---|---|
| IUPAC name Rhenium(IV) oxide | |
| Other names Rhenium dioxide | |
| Identifiers | |
| 3D model (JSmol) | |
| ChemSpider | |
| ECHA InfoCard | 100.031.659 | 
| EC Number | 
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|  PubChem CID | |
|  CompTox Dashboard (EPA) | |
| 
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| 
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| Properties | |
| ReO2 | |
| Molar mass | 218.206 g/mol | 
| Appearance | gray orthorhombic crystals | 
| Density | 11.4 g/cm3 [1] | 
| Melting point | decomposes at 1000 °C [2] | 
| insoluble | |
| Solubility in alkali | insoluble | 
| +44.0·10−6 cm3/mol | |
| Structure | |
| Orthorohmbic, oP12 | |
| Pbcn, No. 60 | |
| Hazards | |
| NFPA 704 (fire diamond) | |
| Safety data sheet (SDS) | Aldrich MSDS | 
| Related compounds | |
| Other anions  | Rhenium(VII) oxide Rhenium(III) oxide Rhenium(III) chloride | 
| Other cations  | manganese(IV) oxide Technetium(IV) oxide | 
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Rhenium(IV) oxide or rhenium dioxide is the inorganic compound with the formula ReO2. This gray to black crystalline solid is a laboratory reagent that can be used as a catalyst. It adopts the rutile structure.
It forms via comproportionation: [3]
Single crystals are obtained by chemical transport, using iodine as the transporting agent.: [4]
At high temperatures it undergoes disproportionation:
It forms rhenates with alkaline hydrogen peroxide and oxidizing acids. [5] In molten sodium hydroxide it forms sodium rhenate: [6]