 | |
| Names | |
|---|---|
| Other names thallium trioxide, thallium sesquioxide | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider |
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| ECHA InfoCard | 100.013.846 |
| EC Number |
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| UNII | |
| |
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| Properties[1] | |
| Tl2O3 | |
| Molar mass | 456.76 g/mol |
| Appearance | dark brown solid |
| Density | 10.19 g/cm3, solid (22 °C) |
| Melting point | 717 °C (1,323 °F; 990 K) |
| Boiling point | 875 °C (1,607 °F; 1,148 K) (decomposes) |
| insoluble | |
| +76.0·10−6 cm3/mol | |
| Structure | |
| Cubic, (Bixbyite)cI80[2] | |
| Ia3 (No. 206) | |
| Hazards | |
| GHS labelling:[3] | |
   | |
| Danger | |
| H300+H330,H373,H411 | |
| P273,P301+P310+P330,P304+P340+P310,P314 | |
| NFPA 704 (fire diamond) | |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 44 mg/kg (oral, rat) |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Thallium(III) oxide, also known asthallic oxide, is a chemical compound ofthallium andoxygen. It occurs in nature as the rare mineralavicennite.[4] Its structure is related to that of Mn2O3 which has abixbyite like structure. Tl2O3 is metallic with high conductivity and is a degenerate n-typesemiconductor which may have potential use insolar cells.[5] A method of producing Tl2O3 byMOCVD is known.[6] Any practical use of thallium(III) oxide will always have to take account of thallium's poisonous nature. Contact withmoisture andacids may form poisonous thallium compounds.
It is produced by the reaction of thallium with oxygen orhydrogen peroxide in an alkaline thallium(I) solution. Alternatively, it can be created by the oxidation ofthallium(I) nitrate by chlorine in an aqueouspotassium hydroxide solution.[7]
