Chlorodiphenylphosphine is an
organophosphorus compound
Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective in ...
with the formula (C
6H
5)
2PCl, abbreviated Ph
2PCl. 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 Ph
2P group into molecules, which includes many ligands.
[Quin, L. D. ''A Guide to Organophosphorus Chemistry''; Wiley IEEE: New York, 2000; pp 44-69. ] Like other halophosphines, Ph
2PCl is reactive with many
nucleophile
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are ...
s such as water and easily
oxidized
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
even by air.
Synthesis and reactions
Chlorodiphenylphosphine is produced on a commercial scale from
benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...
and
phosphorus trichloride
Phosphorus trichloride is an inorganic compound with the chemical formula PCl3. A colorless liquid when pure, it is an important industrial chemical, being used for the manufacture of phosphites and other organophosphorus compounds. It is toxic a ...
(PCl
3).
Benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...
reacts with
phosphorus trichloride
Phosphorus trichloride is an inorganic compound with the chemical formula PCl3. A colorless liquid when pure, it is an important industrial chemical, being used for the manufacture of phosphites and other organophosphorus compounds. It is toxic a ...
at extreme temperatures around 600 °C to give
dichlorophenylphosphine
Dichlorophenylphosphine is an organophosphorus compound with the formula C6H5PCl2. This colourless viscous liquid is commonly used in the synthesis of organophosphines.
Dichlorophenylphosphine is commercially available. It may be prepared by an ...
(PhPCl
2) and HCl.
Redistribution of PhPCl
2 in the gas phase at high temperatures results in chlorodiphenylphosphine.
[
:2PhPCl2 → Ph2PCl + PCl3
Alternatively such compounds are prepared by redistribution reactions starting with ]triphenylphosphine
Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and often abbreviated to P Ph3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists a ...
and phosphorus trichloride
Phosphorus trichloride is an inorganic compound with the chemical formula PCl3. A colorless liquid when pure, it is an important industrial chemical, being used for the manufacture of phosphites and other organophosphorus compounds. It is toxic a ...
.
:PCl3 + 2PPh3 → 3Ph2PCl
Chlorodiphenylphosphine hydrolyzes to give diphenylphosphine oxide. Reduction with sodium affords tetraphenyldiphosphine
Tetraphenyldiphosphine is the organophosphorus compound with the formula Ph2sub>2, where Ph = phenyl (C6H5). It is a white, air-sensitive solid that dissolves in nonpolar solvents. It is a centrosymmetric molecule with a P-P bond of 2.2592 Å.
...
:
:2Ph2PCl + 2Na → 2P">h2Psub>2 + 2NaCl
With ammonia and elemental sulfur, it converts to the thiophosphorylamide:
:Ph2PCl + 2NH3 + S → Ph2P(S)NH2 + NH4Cl
Uses
Chlorodiphenylphosphine, along with other chlorophosphines, is used in the synthesis of various phosphine
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting ...
s. A typical route uses Grignard reagent
A Grignard reagent or Grignard compound is a chemical compound with the general formula , where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride and phenylmagnesium bromide ...
s:[Svara, J.; Weferling, N.; Hofmann, T. "Phosphorus Compounds, Organic," In 'Ullmann's Encyclopedia of Industrial Chemistry, 7th ed.; Wiley-VCH: 2008; ; Accessed: February 18, 2008.]
:Ph2PCl + MgRX → Ph2PR + MgClX
The phosphine
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting ...
s produced from reactions with Ph2PCl are further developed and used as pesticide
Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...
s (such as EPN), stabilizers for plastics (Sandostab P-EPQ), various halogen compound catalysts
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
, flame retardant
The term flame retardants subsumes a diverse group of chemicals that are added to manufactured materials, such as plastics and textiles, and surface finishes and coatings. Flame retardants are activated by the presence of an ignition source a ...
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
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable is ...
via its reaction with sodium metal in refluxing dioxane
1,4-Dioxane () is a heterocyclic organic compound, classified as an ether. It is a colorless liquid with a faint sweet odor similar to that of diethyl ether. The compound is often called simply dioxane because the other dioxane isomers ( 1,2- ...
.
:Ph2PCl + 2 Na → Ph2PNa + NaCl
Diphenylphosphine
Diphenylphosphine, also known as diphenylphosphane, is an organophosphorus compound with the formula (C6H5)2PH. This foul-smelling, colorless liquid is easily oxidized in air. It is a precursor to organophosphorus ligands for use as catalysts.
Syn ...
can be synthesized in the reaction of Ph2PCl and LiAlH4, the latter usually used in excess.
:4 Ph2PCl + LiAlH4 → 4 Ph2PH + LiCl + AlCl3
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.[O. Kühl "Phosphorus-31 NMR Spectroscopy" Springer, Berlin, 2008. ]
References
{{reflist
Phosphines
Phenyl compounds