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DeutschPolonium dibromide
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| Systematic IUPAC name Polonium dibromide | |
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| Properties | |
| PoBr2 | |
| Molar mass | 369.791 g mol−1 |
| Appearance | purple-brown crystalline solid[1][2] |
| Melting point | 270 °C (518 °F; 543 K) (decomposes)[1][2] (sublimes at 110 °C)[2] |
| Solubility | soluble in hydrobromic acid and ketones[2] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Polonium dibromide (also known as polonium(II) bromide) is a chemical compound with the formula PoBr2. This salt is a purple-brown crystalline solid at room temperature.[1][2] It sublimes (decomposing slightly) at 110 °C/30 μ and decomposes when melted in nitrogen gas at 270–280 °C.[2]
Preparation
[edit]Polonium dibromide may be prepared by:
- thermal degradation of polonium tetrabromide (PoBr4) in a vacuum at 200 °C;[2]
- dehalogenation of polonium tetrabromide by hydrogen sulfide at low temperatures (however, this does not form pure polonium dibromide, even upon heating).[1][2]
Chemistry
[edit]Polonium dibromide forms purple solutions in hydrobromic acid (prepared similarly to solutions of polonium dichloride) and ketones, although the latter are rapidly oxidised to polonium(IV). Solid polonium dibromide is rapidly reduced to metallic polonium upon reaction with ammonia.[2]
References
[edit]- ^ a b c d Holleman, Arnold Frederik; Wiberg, Egon (2001), Wiberg, Nils (ed.), Inorganic Chemistry, translated by Eagleson, Mary; Brewer, William, San Diego/Berlin: Academic Press/De Gruyter, p. 594, ISBN 0-12-352651-5
- ^ a b c d e f g h i Bagnall, K. W. (1962). "The Chemistry of Polonium". Advances in Inorganic Chemistry and Radiochemistry. New York: Academic Press. pp. 197–230. ISBN 978-0-12-023604-6. Retrieved June 14, 2012.