Polonium tetrachloride
Polonium tetrachloride (also known as polonium(IV) chloride) is a chemical compound with the formula PoCl4. The salt is a hygroscopic bright yellow crystalline solid at room temperature. Above 200 °C, it tends to decompose into polonium dichloride and excess chlorine, similar to selenium tetrachloride and tellurium tetrachloride.[1]
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| Systematic IUPAC name
Polonium tetrachloride | |
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| Properties | |
| PoCl4 | |
| Molar mass | 350.79 g/mol |
| Appearance | Bright yellow crystalline solid[1] |
| Melting point | ≈ 300 °C (in chlorine)[1] |
| Boiling point | 390 °C (734 °F; 663 K) |
| soluble, but rather slow hydrolysis | |
| Solubility | very soluble in hydrochloric acid and thionyl chloride, moderately soluble in ethanol and acetone, decomposes in dilute nitric acid |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Structure
Polonium tetrachloride is either monoclinic or triclinic.
Appearance
Polonium tetrachloride is bright yellow at room temperature. At its melting point (300 °C), it becomes straw yellow, and at its boiling point (390 °C), it becomes scarlet. Its vapours are purple-brown until 500 °C, when they turn blue-green.[1]
Preparation
Polonium tetrachloride may be prepared by:
- halogenation of polonium dioxide with dry hydrogen chloride, gaseous thionyl chloride, or phosphorus pentachloride;[1]
- dissolving of polonium metal in hydrochloric acid;
- heating polonium dioxide to 200 °C in carbon tetrachloride vapour;
- reaction of polonium metal with dry chlorine gas in 200 °C.
Chemistry
Polonium tetrachloride forms a complex with two moles of tributyl phosphate.
Like selenium tetrachloride and tellurium tetrachloride, polonium tetrachloride forms PoCl−
5 and PoCl2−
6 halogen complexes.[1]
References
- 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