| Tetraphenylphosphonium chloride | |
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Tetraphenylphosphonium chloride |
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| Identifiers | |
| CAS number | 2001-45-8 |
| PubChem | 164911 |
| ChemSpider | 144578 |
| ChEMBL | CHEMBL223885 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C24H20ClP |
| Molar mass | 374.84 g/mol |
| Appearance | colourless solid |
| Density | 1.27 |
| Melting point |
272-274 |
| Solubility in water | organic solvents |
| Hazards | |
| R-phrases | 36/37/38 |
| S-phrases | 26-36 |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| 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,[1] which is normal item of commerce, as well as a monohydrate[2] and a dihydrate.[3]
In X-ray crystallography, PPh4+ 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.
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of the crystal structure |
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PPh4Cl and many analogous compounds can be prepared by thereaction of chlorobenzene with triphenylphosphine catalysed by nickel salts:[4]
The compound was originally prepared as the corresponding bromide salt (CAS# 2751-90-8), which in turn was synthesized by passing dry oxygen through the reaction of phenylmagnesium bromide and triphenylphosphine[5] The synthesis probably proceeds via the reaction of the Grignard reagent with triphenylphosphine oxide.