Triphenylphosphine dichloride

Structural formula
General
Surname	Triphenylphosphine dichloride
other names	Dichloro (triphenyl) -λ 5 -phosphine ( IUPAC ); Dichlorotriphenylphosphorane;
Molecular formula	C 18 H 15 Cl 2 P
External identifiers / databases
EC number	607-677-7
ECHA InfoCard	100.107.819
PubChem	260420
ChemSpider	228579
Wikidata	Q7843277
properties
Molar mass	333.19 g mol −1
Melting point	176 ° C
safety instructions
H and P phrases	H: 228-314-350
	P: 201-210-280-305 + 351 + 338-310
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Triphenylphosphine dichloride is a widely used chlorinating agent in organic chemistry . Applications include the conversion of alcohols and ethers to alkyl chlorides , the cleavage of epoxides to vicinal dichlorides, and the chlorination of carboxylic acids to acyl chlorides.

structure

In polar solvents such as acetonitrile or dichloromethane , the substance adopts an ionic phosphonium salt structure, [Ph ₃ PCl ⁺ ] Cl ^- while it is present as an unsolvated trigonal bipyramide molecule in non-polar solvents such as diethyl ether . Two [Ph ₃ PCl ⁺ ] species can also adopt an unusual binuclear ion structure - both interact with a Cl ^- via long Cl-Cl contacts.

Structure with the mutually twisted phenyl rings

synthesis

Triphenylphosphine dichloride is made by adding chlorine to triphenylphosphine in solution.

{\ displaystyle {\ ce {Ph3P + Cl2 -> Ph3PCl2}}}

Another synthesis route is via the reaction of iodobenzene dichloride (PhICl ₂ ) and triphenylphosphine.

The chlorination of triphenylphosphine, for example with phosphorus trichloride, was the original route of synthesis, which Victor Grignard discovered in 1931.

Individual evidence

^ ^A ^b V. Grignard , J. Savard: Sur les dérivés magnésiens de la dichlorotriphényl-phosphine et sur les pentaphosphines . In: Compt. Rend. . 192, 1931, pp. 592-595.
↑ ^a ^b Datasheet Dichlorotriphenylphosphorane, 95% from Sigma-Aldrich , accessed on October 11, 2019 ( PDF ).
↑ Jean-Robert Dormoy, Bertrand Castro: Triphenylphosphine Dichloride . In: Encyclopedia of Reagents for Organic Synthesis 2001, ISBN 0471936235 , doi : 10.1002 / 047084289X.rt371 .
↑ Stephen M. Godfrey, Charles A. McAuliffe, Joanne M. Sheffield: Structural dependence of the reagent Ph ₃ PCl ₂ on the nature of the solvent, both in the solid state and in solution; X-ray crystal structure of trigonal bipyramidal Ph ₃ PCl ₂ , the first structurally characterized five-coordinate R ₃ PCl ₂ compound . In: Chemical Communications . No. 8, 1998, pp. 921-922. doi : 10.1039 / A800820E .
↑ Stephen M. Godfrey, Charles A. McAuliffe, Robin G. Pritchard, Joanne M. Sheffield: An X-ray crystallorgraphic study of the reagent Ph ₃ PCl ₂ ; not charge-transfer, R ₃ P – Cl – Cl, trigonal bipyramidal or [R ₃ PCl] Cl but an unusual dinuclear ionic species, [Ph ₃ PCl ⁺ ⋯ Cl ^- ⋯ ⁺ CIPPH ₃ ] Cl containing long Cl – Cl contacts . In: Chem. Commun . No. 22, 1996, pp. 2521-2522. doi : 10.1039 / CC9960002521 .

[Grignard-1] A ^b V. Grignard , J. Savard: Sur les dérivés magnésiens de la dichlorotriphényl-phosphine et sur les pentaphosphines . In: Compt. Rend. . 192, 1931, pp. 592-595.

[Sigma-2] Datasheet Dichlorotriphenylphosphorane, 95% from Sigma-Aldrich , accessed on October 11, 2019 ( PDF ).

[3] Jean-Robert Dormoy, Bertrand Castro: Triphenylphosphine Dichloride . In: Encyclopedia of Reagents for Organic Synthesis 2001, ISBN 0471936235 , doi : 10.1002 / 047084289X.rt371 .

[4] Stephen M. Godfrey, Charles A. McAuliffe, Joanne M. Sheffield: Structural dependence of the reagent Ph ₃ PCl ₂ on the nature of the solvent, both in the solid state and in solution; X-ray crystal structure of trigonal bipyramidal Ph ₃ PCl ₂ , the first structurally characterized five-coordinate R ₃ PCl ₂ compound . In: Chemical Communications . No. 8, 1998, pp. 921-922. doi : 10.1039 / A800820E .

[5] Stephen M. Godfrey, Charles A. McAuliffe, Robin G. Pritchard, Joanne M. Sheffield: An X-ray crystallorgraphic study of the reagent Ph ₃ PCl ₂ ; not charge-transfer, R ₃ P – Cl – Cl, trigonal bipyramidal or [R ₃ PCl] Cl but an unusual dinuclear ionic species, [Ph ₃ PCl ⁺ ⋯ Cl ^- ⋯ ⁺ CIPPH ₃ ] Cl containing long Cl – Cl contacts . In: Chem. Commun . No. 22, 1996, pp. 2521-2522. doi : 10.1039 / CC9960002521 .