Triphenylphosphine dichloride

Triphenylphosphine dichloride

Names
IUPAC name Dichlorotriphenyl-λ5-phosphane
Other names Dichlorotriphenylphosphorane
Identifiers
CAS Number	2526-64-9 Y
3D model (JSmol)	Interactive image
ChemSpider	228579
ECHA InfoCard	100.107.819
PubChem CID	260420
InChI InChI=1S/C18H15Cl2P/c19-21(20,16-10-4-1-5-11-16,17-12-6-2-7-13-17)18-14-8-3-9-15-18/h1-15H  Key: ASWXNYNXAOQCCD-UHFFFAOYSA-N
SMILES c1ccc(cc1)P(c2ccccc2)(c3ccccc3)(Cl)Cl
Properties
Chemical formula	C18H15Cl2P
Molar mass	333.19 g/mol
Melting point	176 °C (349 °F; 449 K) 85-100 °C
Solubility in water	Reacts
Related compounds
Related compounds	Phosphoranes Triphenylphosphine Phosphorus trichloride Phosphorus pentachloride Phosphorus halides Tetraphenylphosphonium chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
(what is Y ?)
Infobox references

Triphenylphosphine dichloride, Ph₃PCl₂, is a chlorinating agent widely used 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.

In polar solvents such as acetonitrile or dichloromethane solutions, Ph₃PCl₂ adopts an ionic phosphonium salt structure, [Ph₃PCl⁺]Cl⁻, whereas in non-polar solvents like diethyl ether it exists as a non-solvated trigonal bipyramidal molecule. Two [Ph₃PCl⁺] species can also adopt an unusual dinuclear ionic structure—both interacting with a Cl⁻ via long Cl–Cl contacts.

Triphenylphosphine dichloride is usually prepared fresh by the addition of chlorine to triphenylphosphine.

Both reagents are typically used in solution to ensure the correct stoichiometry.

Ph₃PCl₂ can also be obtained by the reaction of iodobenzene dichloride (PhICl₂) and triphenylphosphine.

Alternatively, Ph₃PCl₂ can be obtained by chlorination of triphenylphosphine oxide with, for example, phosphorus trichloride, as in Grignard's original 1931 synthesis.