Phosphorus triiodide

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Structural formula
Structure of phosphorus triiodide
General
Surname Phosphorus triiodide
other names

Phosphorus (III) iodide

Molecular formula PI 3
Brief description

red solid

External identifiers / databases
CAS number 13455-01-1
EC number 236-647-2
ECHA InfoCard 100.033.302
PubChem 83485
ChemSpider 75323
Wikidata Q418115
properties
Molar mass 411.69 g mol −1
Physical state

firmly

density

4.18 g cm −3

Melting point

61 ° C

solubility

Decomposes in water

safety instructions
GHS labeling of hazardous substances
05 - Corrosive 07 - Warning

danger

H and P phrases H: 314-335
P: 261-280-305 + 351 + 338-310
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

  1. ^ 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 .
  2. a b c d data sheet Phosphorus triiodide from Sigma-Aldrich , accessed on April 20, 2011 ( PDF ).
  3. Data phosphorus triiodide from Acros, accessed on 20 February 2010 .
  4. 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 ).