Tetraphenylphosphonium

Tetraphenylphosphonium chloride

Names
IUPAC name Tetraphenylphosphonium chloride
Identifiers
CAS Number	2001-45-8 N
3D model (Jmol)	Interactive image
ChemSpider	144578 Y
ECHA InfoCard	100.016.265
PubChem CID	164911
InChI InChI=1S/C24H20P.ClH/c1-5-13-21(14-6-1)25(22-15-7-2-8-16-22,23-17-9-3-10-18-23)24-19-11-4-12-20-24;/h1-20H;1H/q+1;/p-1 Y Key: WAGFXJQAIZNSEQ-UHFFFAOYSA-M Y InChI=1S/C24H20P.ClH/c1-5-13-21(14-6-1)25(22-15-7-2-8-16-22,23-17-9-3-10-18-23)24-19-11-4-12-20-24;/h1-20H;1H/q+1;/p-1 Key: WAGFXJQAIZNSEQ-REWHXWOFAO Key: WAGFXJQAIZNSEQ-UHFFFAOYSA-M
SMILES [Cl-].c1c(cccc1)[P+](c2ccccc2)(c3ccccc3)c4ccccc4
Properties
Chemical formula	C24H20ClP
Molar mass	374.84 g/mol
Appearance	colourless solid
Density	1.27 g dm−3
Melting point	272 to 274 °C (522 to 525 °F; 545 to 547 K)
Hazards
R-phrases	36/37/38
S-phrases	26-36
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Tetraphenylphosphonium chloride is the chemical compound with the formula (C₆H₅)₄PCl, abbreviated Ph₄PCl or PPh₄Cl. Tetraphenylphosphonium and especially tetraphenylarsonium salts were formerly of interest in gravimetric analysis of perchlorate and related oxyanions. This colourless salt is used to generate lipophilic salts from inorganic and organometallic anions. Thus, Ph₄P⁺ is useful as a phase-transfer catalyst, again because it allows inorganic anions to dissolve in organic solvents.

The cation is tetrahedral. PPh₄Cl crystallises as the anhydrous salt, which is normal item of commerce, as well as a monohydrate and a dihydrate.

In X-ray crystallography, PPh+
4 salts are of interest as they often crystallise easily. The rigidity of the phenyl groups facilitates packing and elevates the melting point relative to alkyl-based quaternary ammonium salts. Also, since these salts are soluble in organic media, a wide range of solvents can be employed for their crystallisation.

PPh₄Cl and many analogous compounds can be prepared by the reaction of chlorobenzene with triphenylphosphine catalysed by nickel salts:

The compound was originally prepared as the corresponding bromide salt (CAS No. 2751-90-8), which in turn was synthesized by passing dry oxygen through the reaction of phenylmagnesium bromide and triphenylphosphine. The synthesis probably proceeds via the reaction of the Grignard reagent with triphenylphosphine oxide.