Chlorodiphenylphosphine
Encyclopedia
Chlorodiphenylphosphine is an organophosphorus compound with the formula (C6H5)2PCl, abbreviated Ph2PCl. It is a colourless oily liquid with a pungent odor that is often described as being garlic-like and detectable even in the ppb
range. It is useful reagent for introducing the Ph2P group into molecules, which includes many ligand. Like other halophosphines, Ph2PCl is reactive with many nucleophile
s such as water and easily oxidized
even by air.
and phosphorus trichloride
(PCl3). Benzene
reacts with phosphorus trichloride
at extreme temperatures around 600 °C to give dichlorophenylphosphine
(PhPCl2). Redistribution of PhPCl2 in the gas phase at high temperatures results in chlorodiphenylphosphine.
Alternatively such compounds are prepared by redistribution reactions starting with triphenylphosphine
and phosphorus trichloride
. Synthesis of Ph2PCl by the direct reaction of phenylmagnesium bromide
and phosphorus trichloride is not practiced. On the other hand, PCl3 can be usefully converted to its monoamide, which in turn undergoes alkylation or arylation. Subsequent removal of the amide gives :
s. A typical route uses Grignard reagents:
The phosphine
s produced from reactions with Ph2PCl are further developed and used as pesticide
s (EPN or ethyl p-nitrophenyl thionobenzenephosphonate), stabilizers for plastics (Sandostab P-EPQ), various halogen compound catalysts
, flame retardant
s (cyclic phosphinocarboxylic anhydride), as well as UV-hardening paint systems (used in dental materials) making Ph2PCl an important intermediate in the industrial world.
.
Diphenylphosphine
can be synthesized in the reaction of Ph2PCl and LiAlH4, the latter usually used in excess.
Both Ph2PNa and Ph2PH are also used in the synthesis of organophosphine ligands.
PPB
PPB can stand for:* Party political broadcast, a type of political programming in the United Kingdom* parts-per-billion, a unit of concentration* Portland Police Bureau, a police agency for the city of Portland...
range. It is useful reagent for introducing the Ph2P group into molecules, which includes many ligand. Like other halophosphines, Ph2PCl is reactive with many nucleophile
Nucleophile
A nucleophile is a species that donates an electron-pair to an electrophile to form a chemical bond in a reaction. All molecules or ions with a free pair of electrons can act as nucleophiles. Because nucleophiles donate electrons, they are by definition Lewis bases.Nucleophilic describes the...
s such as water and easily oxidized
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
even by air.
Synthesis and reactions
Chlorodiphenylphosphine is produced on a commercial scale from benzeneBenzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
and phosphorus trichloride
Phosphorus trichloride
Phosphorus trichloride is a chemical compound of phosphorus and chlorine, having chemical formula PCl3. Its shape is trigonal pyramidal. It is the most important of the three phosphorus chlorides. It is an important industrial chemical, being used for the manufacture of organophosphorus compounds...
(PCl3). Benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
reacts with phosphorus trichloride
Phosphorus trichloride
Phosphorus trichloride is a chemical compound of phosphorus and chlorine, having chemical formula PCl3. Its shape is trigonal pyramidal. It is the most important of the three phosphorus chlorides. It is an important industrial chemical, being used for the manufacture of organophosphorus compounds...
at extreme temperatures around 600 °C to give dichlorophenylphosphine
Dichlorophenylphosphine
Dichlorophenylphosphine is an organophosphorus compound with the formula C6H5PCl2. This colourless viscous liquid is commonly used in the synthesis of phosphine ligands....
(PhPCl2). Redistribution of PhPCl2 in the gas phase at high temperatures results in chlorodiphenylphosphine.
- 2 PhPCl2 → Ph2PCl + PCl3
Alternatively such compounds are prepared by redistribution reactions starting with triphenylphosphine
Triphenylphosphine
Triphenylphosphine is a common organophosphorus compound with the formula P3 - often abbreviated to PPh3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists as relatively air stable, colorless crystals at room temperature...
and phosphorus trichloride
Phosphorus trichloride
Phosphorus trichloride is a chemical compound of phosphorus and chlorine, having chemical formula PCl3. Its shape is trigonal pyramidal. It is the most important of the three phosphorus chlorides. It is an important industrial chemical, being used for the manufacture of organophosphorus compounds...
. Synthesis of Ph2PCl by the direct reaction of phenylmagnesium bromide
Phenylmagnesium bromide
Phenylmagnesium bromide, with the simplified formula , is a magnesium-containing organometallic compound. It is so commonly used that it is commercially available as a solution in diethyl ether or tetrahydrofuran . Phenylmagnesium bromide is a Grignard reagent...
and phosphorus trichloride is not practiced. On the other hand, PCl3 can be usefully converted to its monoamide, which in turn undergoes alkylation or arylation. Subsequent removal of the amide gives :
- PCl3 + 2 (iPr)2NH → (iPr)2NH2Cl + (iPr)2NPCl22NPCl2 + 2 PhMgBr → (iPr)2NPPh2 + 2 MgBrCl2NPPh2 + 2 HCl → (iPr)2NH2Cl + PPh2Cl
Uses
Ph2PCl, along with other chlorophosphines, is used in the synthesis of various phosphinePhosphine
Phosphine is the compound with the chemical formula PH3. It is a colorless, flammable, toxic gas. Pure phosphine is odourless, but technical grade samples have a highly unpleasant odor like garlic or rotting fish, due to the presence of substituted phosphine and diphosphine...
s. A typical route uses Grignard reagents:
- Ph2PCl + MgRX → Ph2PR + MgClX
The phosphine
Phosphine
Phosphine is the compound with the chemical formula PH3. It is a colorless, flammable, toxic gas. Pure phosphine is odourless, but technical grade samples have a highly unpleasant odor like garlic or rotting fish, due to the presence of substituted phosphine and diphosphine...
s produced from reactions with Ph2PCl are further developed and used as pesticide
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
s (EPN or ethyl p-nitrophenyl thionobenzenephosphonate), stabilizers for plastics (Sandostab P-EPQ), various halogen compound catalysts
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
, flame retardant
Flame retardant
Flame retardants are chemicals used in thermoplastics, thermosets, textiles and coatings that inhibit or resist the spread of fire. These can be separated into several different classes of chemicals:...
s (cyclic phosphinocarboxylic anhydride), as well as UV-hardening paint systems (used in dental materials) making Ph2PCl an important intermediate in the industrial world.
Precursor to diphenylphosphido derivatives
Chlorodiphenylphosphine is used in the synthesis of sodium diphenylphosphide via its reaction with sodium metal in refluxing dioxane1,4-Dioxane
1,4-Dioxane, often called dioxane because the other isomers of dioxane are rare, is a heterocyclic organic compound. It is a colorless liquid with a faint sweet odor similar to that of diethyl ether. It is classified as an ether. This colorless liquid is mainly used as a stabilizer for the solvent...
.
- Ph2PCl + 2 Na → Ph2PNa + NaCl
Diphenylphosphine
Diphenylphosphine
Diphenylphosphine, also known as diphenylphosphane, is organophosphorus compound with the formula 2PH. This foul smelling, colorless liquid is easily oxidized in air...
can be synthesized in the reaction of Ph2PCl and LiAlH4, the latter usually used in excess.
- 4 Ph2PCl + LiAlH4 → 4 Ph2PH + LiCl + AlCl4
Both Ph2PNa and Ph2PH are also used in the synthesis of organophosphine ligands.
Characterization
The quality of chlorodiphenylphosphine is often checked by 31P NMR spectroscopy.| Compound | 31P chemical shift (ppm vs 85% H3PO4) |
|---|---|
| PPh3 | -6 |
| PPh2Cl | 81.5 |
| PPhCl2 | 165 |
| PCl3 | 218 |