Triphenylphosphine oxide

Last updated
Triphenylphosphine oxide
Triphenylphosphine-oxide-2D-skeletal.png
Triphenylphosphine-oxide-from-xtal-3D-vdW-A.png
Sample of Triphenylphosphine oxide.jpg
Names
Preferred IUPAC name
Triphenyl-λ5-phosphanone
Other names
Triphenylphosphine oxide
Identifiers
3D model (JSmol)
745854
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.011.217 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 212-338-8
6758
PubChem CID
RTECS number
  • SZ1676000
UNII
  • InChI=1S/C18H15OP/c19-20(16-10-4-1-5-11-16,17-12-6-2-7-13-17)18-14-8-3-9-15-18/h1-15H Yes check.svgY
    Key: FIQMHBFVRAXMOP-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C18H15OP/c19-20(16-10-4-1-5-11-16,17-12-6-2-7-13-17)18-14-8-3-9-15-18/h1-15H
    Key: FIQMHBFVRAXMOP-UHFFFAOYAB
  • O=P(c1ccccc1)(c2ccccc2)c3ccccc3
Properties
C18H15OP
Molar mass 278.29 g/mol
Appearancewhite crystals
Density 1.212g/cm^3
Melting point 154 to 158 °C (309 to 316 °F; 427 to 431 K)
Boiling point 360 °C (680 °F; 633 K)
low
Solubility in other solventspolar organic solvents
Structure
tetrahedral
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
slight
GHS labelling: [1]
GHS-pictogram-exclam.svg
Warning
H302, H412
P261, P264, P270, P271, P273, P280, P301+P312, P302+P352, P304+P340, P305+P351+P338, P312, P330, P332+P313, P337+P313, P362, P403+P233, P405
Related compounds
Related compounds
P(C6H5)3S;

P(C6H5)3; POCl3; PCl5

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Triphenylphosphine oxide (often abbreviated TPPO) is the organophosphorus compound with the formula OP(C6H5)3, also written as Ph3PO or PPh3O (Ph = C6H5). This colourless crystalline compound is a common but potentially useful waste product in reactions involving triphenylphosphine. It is a popular reagent to induce the crystallizing of chemical compounds.

Contents

Structure and properties

Ph3PO is a tetrahedral molecule related to POCl3. [2] The oxygen center is relatively basic. The rigidity of the backbone and the basicity of the oxygen center make this species a popular agent to crystallize otherwise difficult to crystallize molecules. This trick is applicable to molecules that have acidic hydrogen atoms, e.g. phenols. [3]

Up to now, several modifications of Ph3PO have been found: For example, a monoclinic form crystalizes in the space group P21/c with Z = 4 and a = 15.066(1) Å, b = 9.037(2) Å, c = 11.296(3) Å, and β = 98.47(1)°. [4] The orthorhombic modification crystallizes in the space group Pbca with Z = 4 and 29.089(3) Å, b = 9.1347(9), c = 11.261(1) Å. [5]

TPPO's unique application as a heat-diffuser in many electronic devices is used by law enforcement to train electronics-sniffing dogs. [6]

As a byproduct of organic synthesis

Ph3PO is a byproduct of many useful reactions in organic synthesis including the Wittig, Staudinger, and Mitsunobu reactions. It is also formed when PPh3Cl2 is employed to convert alcohols into alkyl chlorides:

Ph3PCl2 + ROH → Ph3PO + HCl + RCl

Triphenylphosphine can be regenerated from the oxide by treatment with a variety of deoxygenation agents, such as phosgene or trichlorosilane/triethylamine: [7]

Ph3PO + SiHCl3 → PPh3 + 1/n (OSiCl2)n + HCl

Triphenylphosphine oxide can be difficult to remove from reaction mixtures by means of chromatography. It is poorly soluble in hexane and cold diethyl ether. Trituration or chromatography of crude products with these solvents often leads to a good separation of triphenylphosphine oxide. Its removal is facilitated by conversion to its Mg(II) complex, which is poorly soluble in toluene or dichloromethane and can be filtered off. [8] An alternative filtration method where ZnCl2(TPPO)2 is formed upon addition of ZnCl2 may be used with more polar solvents such as ethanol, ethyl acetate and tetrahydrofuran. [9]

Coordination chemistry

NiCl2(OPPh3)2 Dichlorobis(triphenylphosphine-oxide)nickel(II)-from-xtal-3D-balls.png
NiCl2(OPPh3)2

Ph3PO is a ligand for "hard" metal centers. A representative complex is the tetrahedral species NiCl2(OPPh3)2. [10]

Ph3PO is a common impurity in PPh3. The oxidation of PPh3 by oxygen, including air, is catalyzed by many metal ions:

2 PPh3 + O2 → 2 Ph3PO

Related Research Articles

In organic chemistry, an acyl chloride is an organic compound with the functional group −C(=O)Cl. Their formula is usually written R−COCl, where R is a side chain. They are reactive derivatives of carboxylic acids. A specific example of an acyl chloride is acetyl chloride, CH3COCl. Acyl chlorides are the most important subset of acyl halides.

<span class="mw-page-title-main">Wilkinson's catalyst</span> Chemical compound

Wilkinson's catalyst is the common name for chlorido­tris(triphenylphosphine)­rhodium(I), a coordination complex of rhodium with the formula [RhCl(PPh3)3], where 'Ph' denotes a phenyl group). It is a red-brown colored solid that is soluble in hydrocarbon solvents such as benzene, and more so in tetrahydrofuran or chlorinated solvents such as dichloromethane. The compound is widely used as a catalyst for hydrogenation of alkenes. It is named after chemist and Nobel laureate Sir Geoffrey Wilkinson, who first popularized its use.

<span class="mw-page-title-main">Phosphonium</span> Family of polyatomic cations containing phosphorus

In chemistry, the term phosphonium describes polyatomic cations with the chemical formula PR+
4
. These cations have tetrahedral structures. The salts are generally colorless or take the color of the anions.

<span class="mw-page-title-main">Vaska's complex</span> Chemical compound

Vaska's complex is the trivial name for the chemical compound trans-carbonylchlorobis(triphenylphosphine)iridium(I), which has the formula IrCl(CO)[P(C6H5)3]2. This square planar diamagnetic organometallic complex consists of a central iridium atom bound to two mutually trans triphenylphosphine ligands, carbon monoxide and a chloride ion. The complex was first reported by J. W. DiLuzio and Lauri Vaska in 1961. Vaska's complex can undergo oxidative addition and is notable for its ability to bind to O2 reversibly. It is a bright yellow crystalline solid.

<span class="mw-page-title-main">Phosphorus trichloride</span> Chemical compound

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 and reacts readily with water to release hydrogen chloride.

<span class="mw-page-title-main">Triphenylphosphine</span> Chemical compound

Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and 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. It dissolves in non-polar organic solvents such as benzene and diethyl ether.

<span class="mw-page-title-main">Phosphoryl chloride</span> Chemical compound

Phosphoryl chloride is a colourless liquid with the formula POCl3. It hydrolyses in moist air releasing phosphoric acid and fumes of hydrogen chloride. It is manufactured industrially on a large scale from phosphorus trichloride and oxygen or phosphorus pentoxide. It is mainly used to make phosphate esters such as tricresyl phosphate.

Organophosphorus chemistry is the scientific study of the synthesis and properties of organophosphorus compounds, which 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 insecticides, although some are extremely toxic to humans, including sarin and VX nerve agents.

<span class="mw-page-title-main">Carbon tetraiodide</span> Chemical compound

Carbon tetraiodide is a tetrahalomethane with the molecular formula CI4. Being bright red, it is a relatively rare example of a highly colored methane derivative. It is only 2.3% by weight carbon, although other methane derivatives are known with still less carbon.

<span class="mw-page-title-main">Phosphine oxide</span> Class of chemical compounds

Phosphine oxides are phosphorus compounds with the formula OPX3. When X = alkyl or aryl, these are organophosphine oxides. Triphenylphosphine oxide is an example. An inorganic phosphine oxide is phosphoryl chloride (POCl3).

<span class="mw-page-title-main">Chloro(triphenylphosphine)gold(I)</span> Chemical compound

Chloro(triphenylphosphine)gold(I) or triphenylphosphinegold(I) chloride is a coordination complex with the formula (Ph3P)AuCl. This colorless solid is a common reagent for research on gold compounds.

<span class="mw-page-title-main">Tetrakis(triphenylphosphine)platinum(0)</span> Chemical compound

Tetrakis(triphenylphosphine)platinum(0) is the chemical compound with the formula Pt(P(C6H5)3)4, often abbreviated Pt(PPh3)4. The bright yellow compound is used as a precursor to other platinum complexes.

Organophosphines are organophosphorus compounds with the formula PRnH3−n, where R is an organic substituent. These compounds can be classified according to the value of n: primary phosphines (n = 1), secondary phosphines (n = 2), tertiary phosphines (n = 3). All adopt pyramidal structures. Organophosphines are generally colorless, lipophilic liquids or solids. The parent of the organophosphines is phosphine (PH3).

<span class="mw-page-title-main">Bis(triphenylphosphine)iminium chloride</span> Chemical compound

Bis(triphenylphosphine)iminium chloride is the chemical compound with the formula [( 3P)2N]Cl, often abbreviated [(Ph3P)2N]Cl, where Ph is phenyl C6H5, or even abbreviated [PPN]Cl or [PNP]Cl or PPNCl or PNPCl, where PPN or PNP stands for (Ph3P)2N. This colorless salt is a source of the [(Ph3P)2N]+ cation, which is used as an unreactive and weakly coordinating cation to isolate reactive anions. [(Ph3P)2N]+ is a phosphazene.

<span class="mw-page-title-main">Tetraphenylphosphonium chloride</span> Chemical compound

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.

Martin Arthur Bennett FRS is an Australian inorganic chemist. He gained recognition for studies on the co-ordination chemistry of tertiary phosphines, olefins, and acetylenes, and the relationship of their behaviour to homogeneous catalysis.

Oxophilicity is the tendency of certain chemical compounds to form oxides by hydrolysis or abstraction of an oxygen atom from another molecule, often from organic compounds. The term is often used to describe metal centers, commonly the early transition metals such as titanium, niobium, and tungsten. Oxophilicity is often stated to be related to the hardness of the element, within the HSAB theory, but it has been shown that oxophilicity depends more on the electronegativity and effective nuclear charge of the element than on its hardness. This explains why the early transition metals, whose electronegativities and effective nuclear charges are low, are very oxophilic. Many main group compounds are also oxophilic, such as derivatives of aluminium, silicon, and phosphorus(III). The handling of oxophilic compounds often requires air-free techniques.

<span class="mw-page-title-main">Dimethylphenylphosphine</span> Chemical compound

Dimethylphenylphosphine is an organophosphorus compound with a formula P(C6H5)(CH3)2. The phosphorus is connected to a phenyl group and two methyl groups, making it the simplest aromatic alkylphosphine. It is colorless air sensitive liquid. It is a member of series (CH3)3-n(C6H5)2P that also includes n = 0, n = 2, and n = 3 that are often employed as ligands in metal phosphine complexes.

<span class="mw-page-title-main">Dichlorotris(triphenylphosphine)ruthenium(II)</span> Chemical compound

Dichlorotris(triphenylphosphine)ruthenium(II) is a coordination complex of ruthenium. It is a chocolate brown solid that is soluble in organic solvents such as benzene. The compound is used as a precursor to other complexes including those used in homogeneous catalysis.

<span class="mw-page-title-main">Metal-phosphine complex</span>

A metal-phosphine complex is a coordination complex containing one or more phosphine ligands. Almost always, the phosphine is an organophosphine of the type R3P (R = alkyl, aryl). Metal phosphine complexes are useful in homogeneous catalysis. Prominent examples of metal phosphine complexes include Wilkinson's catalyst (Rh(PPh3)3Cl), Grubbs' catalyst, and tetrakis(triphenylphosphine)palladium(0).

References

  1. "Triphenylphosphine oxide". pubchem.ncbi.nlm.nih.gov. Retrieved 12 December 2021.
  2. D. E. C. Corbridge "Phosphorus: An Outline of its Chemistry, Biochemistry, and Technology" 5th Edition Elsevier: Amsterdam. ISBN   0-444-89307-5.
  3. M. C. Etter and P. W. Baures (1988). "Triphenylphosphine oxide as a crystallization aid". J. Am. Chem. Soc. 110 (2): 639–640. doi:10.1021/ja00210a076.
  4. Spek, Anthony L. (1987). "Structure of a second monoclinic polymorph of triphenylphosphine oxide". Acta Crystallographica. C43 (6): 1233–1235. doi:10.1107/S0108270187092345.
  5. Al-Farhan, Khalid A. (1992). "Crystal structure of triphenylphosphine oxide". Journal of Crystallographic and Spectroscopic Research. 22 (6): 687–689. doi:10.1007/BF01160986. S2CID   98335827.
  6. "Electronics-sniffing dogs: How K9s became a secret weapon for solving high-tech crimes". 9 December 2016.
  7. van Kalkeren, H. A.; van Delft, F. L.; Rutjes, F. P. J. T. (2013). "Organophosphorus Catalysis to Bypass Phosphine Oxide Waste". ChemSusChem. 6 (9): 1615–24. doi:10.1002/cssc.201300368. hdl: 2066/117145 . PMID   24039197.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  8. Patent WO 1998007724. "Process for the preparation of 7-alkoxyalkyl-1,2,4-triazolo[1,5-a] pyrimidine derivatives"
  9. Batesky, Donald C.; Goldfogel, Matthew J.; Weix, Daniel J. (2017). "Removal of Triphenylphosphine Oxide by Precipitation with Zinc Chloride in Polar Solvents". The Journal of Organic Chemistry. 82 (19): 9931–9936. doi: 10.1021/acs.joc.7b00459 . PMC   5634519 . PMID   28956444.
  10. D. M. L. Goodgame and M. Goodgame (1965). "Near-Infrared Spectra of Some Pseudotetrahedral Complexes of Cobalt (II) and Nickel(II)". Inorg. Chem. 4 (2): 139–143. doi:10.1021/ic50024a002.