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 (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 ligands.Quin, L. D. ''A Guide to Organophosphorus Chemistry''; Wiley IEEE: New York, 2000; pp 44-69. Like other halophosphines, Ph₂PCl 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 a ...

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 de ...

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 ato ...

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).

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 ato ...

reacts with

at extreme temperatures around 600 °C to give dichlorophenylphosphine (PhPCl₂) and HCl. Redistribution of PhPCl₂ 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 ...

and

. :PCl₃ + 2PPh₃ → 3Ph₂PCl Chlorodiphenylphosphine hydrolyzes to give

diphenylphosphine oxide Diphenylphosphine oxide is an organophosphorus compound with the formula (C6H5)2P(O)H. It is a white solid that soluble in polar organic solvents. Synthesis Diphenylphosphine oxide can be prepared by the reaction of phosphonic esters, such as d ...

. Reduction with sodium affords tetraphenyldiphosphine: :2Ph₂PCl + 2Na → 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 rotti ...

s. A typical route uses Grignard reagents: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

s produced from reactions with Ph₂PCl are further developed and used as pesticides (such as EPN), stabilizers for plastics (Sandostab P-EPQ), various halogen compound catalysts,

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 via its reaction with sodium metal in refluxing dioxane. :Ph₂PCl + 2 Na → Ph₂PNa + NaCl Diphenylphosphine 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 Phosphorus-31 NMR spectroscopy is an analytical chemistry technique that uses nuclear magnetic resonance (NMR) to study chemical compounds that contain phosphorus. Phosphorus is commonly found in organic compounds and coordination complexes (as ...

.O. Kühl "Phosphorus-31 NMR Spectroscopy" Springer, Berlin, 2008.

References

{{reflist Phosphines Phenyl compounds