Phosphorus pentachloride

Structural formula
General
Surname	Phosphorus pentachloride
other names	Phosphorus (V) chloride
Molecular formula	PCl 5
Brief description	colorless to yellowish solid with a pungent odor
External identifiers / databases
EC number	233-060-3
ECHA InfoCard	100.030.043
PubChem	24819
Wikidata	Q283427
properties
Molar mass	208.24 g · mol -1
Physical state	firmly
density	2.1 g cm −3
Melting point	148 ° C (under pressure); The substance has no melting point at normal pressure.;
Sublimation point	162.2 ° C
Vapor pressure	20 Pa (20 ° C)
solubility	violent decomposition in water
safety instructions
H and P phrases	H: 302-330-314-373
	EUH: 014-029
	P: 280-301 + 330 + 331-304 + 340-305 + 351 + 338-309 + 310
MAK	DFG / Switzerland: 1 mg m −3 (measured as inhalable dust )
Toxicological data	660 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Phosphorus pentachloride is a colorless, hygroscopic crystalline mass with a caustic odor. It is mostly yellowish or greenish in color due to partial decomposition into phosphorus trichloride and chlorine .

Extraction and presentation

The technical preparation of phosphorus pentachloride takes place by chlorination of phosphorus trichloride in an equilibrium reaction :

{\ displaystyle \ mathrm {PCl_ {3} \ + Cl_ {2} \ \ rightleftharpoons \ PCl_ {5}}}

The educts are reacted in lead- lined towers in a countercurrent process .

Properties and use

The substance decomposes with water to form phosphoric acid and hydrogen chloride :

{\ displaystyle \ mathrm {\ PCl_ {5} \ + \ 4 \ H_ {2} O \ \ longrightarrow \ \ H_ {3} PO_ {4} \ + \ 5 \ HCl}}

Even at normal temperature, the pentachloride dissociates to form phosphorus trichloride, releasing chlorine. At normal pressure, phosphorus pentachloride does not melt, but sublimes from around 100 ° C. In a closed apparatus it melts under overpressure at 148–160.5 ° C. Crystalline solid phosphorus pentachloride has an ionic structure: [PCl ₄ ] ⁺ [PCl ₆ ] ^- .

In general, phosphorus pentachloride is used as a chlorinating agent because it gives off chlorine very easily . There are z. B. converted carboxylic acids to the corresponding acid chloride. By reaction with benzophenone can dichlorodiphenylmethane be represented.

safety instructions

Phosphorus pentachloride is very toxic and reacts violently with water, metal oxides , metal powders and organic substances , generating heat and splitting off toxic gases such as phosphoryl chloride , hydrogen chloride and chlorine gas . Furthermore, phosphorus pentachloride reacts with many acids and their salts to form the corresponding acid chlorides . The extremely toxic phosgene is formed from carbonates and phosphorus pentachloride .

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Entry on phosphorus pentachloride in the GESTIS substance database of the IFA , accessed on July 23, 2016(JavaScript required) .
↑ NIOSH. "Phosphorus pentachloride" . Retrieved June 14, 2018.
↑ Entry on Phosphorus pentachloride in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 10026-13-8 or phosphorus pentachloride ), accessed on November 2, 2015.
↑ Data sheet phosphorus pentachloride (PDF) from Merck , accessed on April 5, 2007.
^ ^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 , pp. 757-758.
^ Arnold F. Holleman, Nils Wiberg: Textbook of Inorganic Chemistry. Walter de Gruyter, Berlin 1985, ISBN 3-11-007511-3 , p. 639.
↑ Alberto Spaggiari, Daniele Vaccari, Paolo Davoli, Giovanni Torre, Fabio Prati: A Mild Synthesis of Vinyl-Halides and -Dihalides Using Triphenyl Phosphite − Halogen-Based Reagents. In: The Journal of Organic Chemistry . 72, 2007, p. 2216, doi : 10.1021 / jo061346g .

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Entry on phosphorus pentachloride in the GESTIS substance database of the IFA , accessed on July 23, 2016(JavaScript required) .

[2] NIOSH. "Phosphorus pentachloride" . Retrieved June 14, 2018.

[CLP_100.030.043-3] Entry on Phosphorus pentachloride in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[4] Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 10026-13-8 or phosphorus pentachloride ), accessed on November 2, 2015.

[5] Data sheet phosphorus pentachloride (PDF) from Merck , accessed on April 5, 2007.

[howi101-6] 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 , pp. 757-758.

[HoWi91-7] Arnold F. Holleman, Nils Wiberg: Textbook of Inorganic Chemistry. Walter de Gruyter, Berlin 1985, ISBN 3-11-007511-3 , p. 639.

[DOI10.1021/jo061346g-8] Alberto Spaggiari, Daniele Vaccari, Paolo Davoli, Giovanni Torre, Fabio Prati: A Mild Synthesis of Vinyl-Halides and -Dihalides Using Triphenyl Phosphite − Halogen-Based Reagents. In: The Journal of Organic Chemistry . 72, 2007, p. 2216, doi : 10.1021 / jo061346g .