Phosphorus triiodide
Structural formula | |||||||||||||||||||
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General | |||||||||||||||||||
Surname | Phosphorus triiodide | ||||||||||||||||||
other names |
Phosphorus (III) iodide |
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Molecular formula | PI 3 | ||||||||||||||||||
Brief description |
red solid |
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properties | |||||||||||||||||||
Molar mass | 411.69 g mol −1 | ||||||||||||||||||
Physical state |
firmly |
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density |
4.18 g cm −3 |
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Melting point |
61 ° C |
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solubility |
Decomposes in water |
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safety instructions | |||||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Phosphorus triiodide is a chemical compound with the empirical formula PI 3 . It consists of a central phosphorus atom, the symmetric three iodine is surrounded atoms. The compound has a tetrahedral structure, since phosphorus still has a free electron pair in the +3 oxidation state , which forms the fourth corner of the tetrahedron.
presentation
The synthesis of phosphorus triiodide can be achieved by the reaction between white phosphorus and elemental iodine in carbon disulfide .
properties
Phosphorus triiodide is a red solid at room temperature that melts at 61 ° C. The bond length between phosphorus and iodine is 243 pm , the I – P – I bond angle is 102 °.
use
Phosphorus triiodide can be used to synthesize alkyl iodides from the corresponding alcohols . In this way, for example, methyl iodide can be obtained from methanol .
Individual evidence
- ^ A b c A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 .
- ↑ a b c d data sheet Phosphorus triiodide from Sigma-Aldrich , accessed on April 20, 2011 ( PDF ).
- ↑ Data phosphorus triiodide from Acros, accessed on 20 February 2010 .
- ↑ CS King, WW Hartman: Methyl Iodide In: Organic Syntheses . 13, 1933, p. 60, doi : 10.15227 / orgsyn.013.0060 ; Coll. Vol. 2, 1943, p. 399 ( PDF ).