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Phosphines

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Phosphine (IUPAC name: phosphane) is the compound with the chemical formula PH3. It is a colorless, flammable, toxic gas.

Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like garlic or rotting fish, due to the presence of substituted phosphine and diphosphane (P2H4). With traces of P2H4 present, PH3 is spontaneously flammable in air, burning with a luminous flame. Phosphines are also a group of organophosphorus compounds with the formula R3P (R = organic derivative). Organophosphines are important in catalysts where they complex to various metal ions; complexes derived from a chiral phosphine can catalyze reactions to give chiral, enantioenriched products.

Related to a PH3 is the class of organophosphorus compounds commonly called phosphines. These alkyl and aryl derivatives of phosphine are analogous to organic amines. Common examples include triphenylphosphine ((C6H5)3P) and BINAP, both used as ligands in homogeneous catalysis or triisopropylphosphine. Phosphines are easily oxidized to phosphine oxides as exemplified by the directed synthesis of a phospha-crown, the phosphorus analogue of an aza crown where it is not possible to isolate the phosphine itself.

Scheme 4. Phosphacrown
In step 1 diphosphinoethane coordinates to a ferrocene containing additional carbon monoxide ligands and an acetonitrile ligand. The next step is a hydrophosphination with trivinylphosphine followed by alkylation with ethyl bromide and hydrogenation with hydrogen over palladium on carbon. In the final step the iron template is removed by bromine but oxidation of the phosphine groups is unavoidable.

Phosphine. "Phosphane" redirects here.

Phosphine

For pentavalent organophosphorus compounds, see phosphorane. For the fictional substance used in the K9 tv series, see The Korven. History. Structures and properties. Preparation and occurance. Comparisons of Phosphines and Amines. Synthetic routes. Reactions. Phosphine ligands. Primary and secondary Phosphines.

Applications

Safety. Metal phosphine complex. Phosphines are L-type ligands.

Metal phosphine complex

They are both σ-donors and π-acceptors. Phosphate. Chemical properties[edit] The phosphate ion is a polyatomic ion with the empirical formula PO43− and a molar mass of 94.97 g/mol.

Phosphate

It consists of one central phosphorus atom surrounded by four oxygen atoms in a tetrahedral arrangement. The phosphate ion carries a negative-three formal charge and is the conjugate base of the hydrogen phosphate ion, HPO42−, which is the conjugate base of H2PO4−, the dihydrogen phosphate ion, which in turn is the conjugate base of H 3PO 4, phosphoric acid. A phosphate salt forms when a positively charged ion attaches to the negatively charged oxygen atoms of the ion, forming an ionic compound. Many phosphates are not soluble in water at standard temperature and pressure. Aqueous phosphate exists in four forms. H 3PO 4Phosphoric acidH 2PO− 4Dihydrogen phosphateHPO2− 4Hydrogen phosphatePO3− 4Phosphate More precisely, considering these three equilibrium reactions:

Phosphonate. General ester of phosphonic acid.

Phosphonate

Phosphonates and phosphonic acids are organophosphorus compounds containing C-PO(OH)2 or C-PO(OR)2 groups (where R=alkyl, aryl). Phosphonic acids and phosphonate salts are typically white, nonvolatile solids that are poorly soluble in organic solvents, but soluble in water and common alcohols. Many commercially important compounds are phosphonates, including Glyphosate, the herbicide "Roundup", and Ethephon, a widely used plant growth regulator. Phosphinate. Phosphite. A phosphite in inorganic chemistry is a salt of phosphorous acid, H3PO3 and following the IUPAC naming recommendations the phosphite ion would be PO33−[2] a salt of P(OH)3.

Phosphite

Historically phosphite has referred to salts containing HPO32− and this is because aqueous H3PO3 is not triprotic P(OH)3 but almost exclusively the diprotic HP(O)(OH)2 (IUPAC recommended name of phosphonic acid). The IUPAC recommended name for the HPO32− ion is phosphonate and this naming convention is becoming more common. In the US the IUPAC naming conventions for inorganic compounds are taught at high school, but not as a 'required' part of the curriculum.[3] A well known university level text book follows the IUPAC recommendations.[4] In practise any reference to "phosphite" should be investigated carefully to determine which naming convention is being employed.

The term phosphite is also used to mean phosphite ester, an organophosphorus compound with the formula P(OR)3. Salts containing phosphite, PO33−[edit] Phosphonite. General ester of phosphonous acid Phosphonites are organophosphorus compounds with the formula P(OR)2R.

Phosphonite

They are found in some pesticides and are used as ligands.[1] Preparation[edit] Although they are derivivatives of phosphonous acid (RP(OH)2),[2] they are not prepared from such precursors. Phosphonites are prepared by alcoholysis of organophosphinous chlorides. Cl2PPh + 2 CH3OH → (CH3O)2PPh + 2 HCl. Phosphinite. Phosphorane. The structure of a typical phosphorane group.

Phosphorane

A phosphorane (IUPAC name: λ5-phosphane) is a functional group in organophosphorus chemistry with pentavalent phosphorus. It has the general formula PR5. The parent hydride compound is the unstable molecule PH5. The derivative pentaphenylphosphorane (Ph5P) is stable.[1] Phosphoranes adopt a trigonal bipyramidal molecular geometry with the two apical bonds longer than the three equatorial bonds. Phosphine oxide. General formula of organophosphine oxides Phosphine oxides are phosphorus compounds with the formula OPX3.

Phosphine oxide

When X = alkyl or aryl, these are organophosphine oxides. Triphenylphosphine oxide is an example. An inorganic phosphine oxide is phosphoryl chloride (POCl3). Diphosphenes. Yoshifuji's diphosphene.

Diphosphenes

The phenyl rings are rotated out of the plane but are shown as coplanar for simplicity of presentation. In chemistry, a diphosphene is an organophosphorus compound that has a phosphorus-phosphorus double bond, denoted by R-P=P-R'. These compounds are not common but are of theoretical interest. Normally, compounds with the empirical formula RP exist as rings. However, when the organic substituent is very large, the diphosphene becomes stable. Synthesis and structure[edit] In 1887, H. In 1981, Masaaki Yoshifuji and coworkers reported the first stable diphosphene, Bis(2,4,6-Tri-Tert-Butylphenyl)Diphosphene (sometimes abbreviated as Me*P=PMe*),[2]which is stabilized by very bulky substituents attached to the phosphorus centers. Diphosphene. Diphosphene is a compound having the formula (PH)2.

Diphosphene

It exists as two geometric isomers, E and Z.[1] Diphosphene is also the parent member of the entire class of diphosphene compounds with the formula (PR)2, where R is an organyl group.[2] Jump up ^ Lu, T.; Simmonett, A. Diphosphane. This article is about P2H4. For other uses, see diphosphines. Diphosphane is an inorganic compound with the chemical formula P2H4. This colourless liquid is one of several binary phosphorus hydrides. Diphosphines. Diphosphines, sometimes called bisphosphanes, are organophosphorus compounds used as ligands in inorganic and organometallic chemistry. They are identified by the presence of two phosphino groups linked by a backbone, and are usually chelating.[1] Synthesis[edit] Many widely used diphosphine ligands have the general formula Ar2P(CH2)nPAr2. These compounds can be prepared from the reaction of X(CH2)nX (X=halogen) and MPPh2 (M = alkali metal):[2]