Peroxymonophosphoric acid

Last updated
Peroxymonophosphoric acid
Peroxomonophosphoric acid structure01.svg
Names
IUPAC name
peroxyphosphoric acid
Systematic IUPAC name
(dioxidanido)dihydroxidooxidophosphorus
Other names
  • monoperoxyphosphoric acid
  • permonophosphoric acid
  • peroxomonophosphoric acid
  • PMPA
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
PubChem CID
  • InChI=1S/H3O5P/c1-5-6(2,3)4/h1H,(H2,2,3,4)
    Key: MPNNOLHYOHFJKL-UHFFFAOYSA-N
  • InChI=1S/H3O5P/c1-5-6(2,3)4/h1H,(H2,2,3,4)
  • OOP(=O)(O)O
Properties
H3PO5
Molar mass 114.00 g/mol
Appearancecolorless oil
Solubility soluble in acetonitrile, dioxane
Related compounds
Related compounds
peroxydiphosphoric acid; phosphoric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Peroxymonophosphoric acid (H3PO5) is an oxyacid of phosphorus. It is a colorless viscous oil. Its salts are called peroxymonophosphates. Another peroxyphosphoric acid is peroxydiphosphoric acid, H4P2O8.

Contents

Preparation

Peroxyphosphoric acids were first synthesized and characterized in 1910 by Julius Schmidlin and Paul Massini via the reaction between phosphorus pentoxide and highly-concentrated aqueous solution of hydrogen peroxide. [1] However, this reaction proceeds very vigorously and is difficult to control. Aside from phosphorus pentoxide, syntheses from metaphosphoric acid and diphosphoric acid were also reported.

A less vigorous method of preparing peroxyphosphoric acid by introducing the inert solvent acetonitrile was described by Gerrit Toennies in 1937. This method was shown to be unsuitable in diethyl ether or isoamyl alcohol. [2]

Contemporary methods

Peroxyphosphoric acid is usually produced by treating phosphorus pentoxide and concentrated hydrogen peroxide within an inert solvent like acetonitrile or carbon tetrachloride. [3] [4]

P4O10 + 4H2O2 + 2H2O → 4H3PO5

One method of preparation is the hydrolysis of potassium of lithium peroxydiphosphate in a strong acid such as perchloric acid. [4] The peroxydiphosphate salts can be obtained by electrolysis of their respective phosphate salts. [5]

(P2O8)4− + H2O + 4 H+ → H3PO5 + H3PO4

Peroxydiphosphoric acid is obtained when phosphoric acid is treated with fluorine or oxidized electrolytically. [5]

Properties

The structure of H3PO5, displaying the intramolecular hydrogen bond Peroxomonophosphoric acid structure02.svg
The structure of H3PO5, displaying the intramolecular hydrogen bond

Peroxymonophosphoric acid is a colorless, viscous liquid. It is stabilized by an intramolecular hydrogen bond. [6] The compound is a triprotic acid with acid dissociation constants pKa1 = 1.1, pKa2 = 5.5 and pKa3 = 12.8. In aqueous solutions it slowly undergoes hydrolysis to hydrogen peroxide and phosphoric acid. [7]

H3PO5 + H2O → H3PO4 + H2O2

With excess water, the hydrolysis can be considered pseudo-first order. The half-life for this decomposition is dependent on the pH and temperature, being about 31 hours at 35 °C and 2.5 hours at 61 °C. [7] A solution in acetonitrile also slowly degrades, losing 30% of active oxygen after 26 days of storage at 5 °C. [6] Relatively stable salts can be obtained by neutralization with bases, for example with potassium hydroxide to give the hygroscopic potassium dihydrogenperoxymonophosphate KH2PO5. [5]

Uses and reactions

Peroxyphosphoric acids and peroxyphosphates have few commercial uses. [3]

Reactions with organic compounds

They have been examined in the context of organic synthesis, as an electrophilic reagent for the oxidation of alkenes, alkynes, aromatic compounds and amines. Due to the strongly acidic nature, only relatively acid-stable epoxides can be prepared from alkenes, for example trans-stilbene oxide from trans-stilbene. Less stable epoxides are cleaved or react further; cyclohexene, styrene, and α-methylstyrene yield no isolable epoxides. In the cases of styrene and α-methylstyrene, acid-catalyzed alkyl migrations lead instead to the main products phenylacetic acid and 2-phenylpropionic acid, respectively. [8]

Peroxomonophosphoric acid reaction01.svg

The oxidation of diphenylacetylene at room temperature yields benzil, presumably through an oxirene intermediate. [9]

Peroxomonophosphoric acid reaction02.svg

Peroxymonophosphoric acid is an effective reagent for the hydroxylation of aromatic rings. The conversion of mesitylene to mesitol can be achieved at room temperature in less than four hours. [10]

Peroxomonophosphoric acid reaction03.svg

The compound can be used as an effective oxidizing agent for the Baeyer-Villiger oxidation. Substituted acetophenones can be converted to the corresponding phenyl acetates at 30 °C in high yields. The rate is about 100 times higher in comparison to using peroxybenzoic acid. [11]

Peroxomonophosphoric acid reaction04.svg

Tertiary aromatic amines like dimethylaniline are oxidized to the corresponding amine oxide. [12]

H3PO5 amine oxidation.svg

Oxidation of THF with peroxymonophosphoric acid gives γ-butyrolactone. [6]

Related Research Articles

In chemistry, amines are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines, trimethylamine, and aniline. Inorganic derivatives of ammonia are also called amines, such as monochloramine.

<span class="mw-page-title-main">Epoxide</span> Organic compounds with a carbon-carbon-oxygen ring

In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ethers. They are produced on a large scale for many applications. In general, low molecular weight epoxides are colourless and nonpolar, and often volatile.

In organic chemistry, a nitrile is any organic compound that has a −C≡N functional group. The name of the compound is composed of a base, which includes the carbon of the −C≡N, suffixed with "nitrile", so for example CH3CH2C≡N is called "propionitrile". The prefix cyano- is used interchangeably with the term nitrile in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Nitrile rubber is also widely used as automotive and other seals since it is resistant to fuels and oils. Organic compounds containing multiple nitrile groups are known as cyanocarbons.

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

Phosphorus pentachloride is the chemical compound with the formula PCl5. It is one of the most important phosphorus chlorides/oxychlorides, others being PCl3 and POCl3. PCl5 finds use as a chlorinating reagent. It is a colourless, water-sensitive solid, although commercial samples can be yellowish and contaminated with hydrogen chloride.

<span class="mw-page-title-main">Peroxy acid</span> Organic acid having a peroxide bond

A peroxy acid is an acid which contains an acidic –OOH group. The two main classes are those derived from conventional mineral acids, especially sulfuric acid, and the peroxy derivatives of organic carboxylic acids. They are generally strong oxidizers.

<span class="mw-page-title-main">Peroxymonosulfuric acid</span> Powerful oxidizing agent

Peroxymonosulfuric acid, H
2
SO
5
, is also known as persulfuric acid, peroxysulfuric acid, or Caro's acid. In this acid, the S(VI) center adopts its characteristic tetrahedral geometry; the connectivity is indicated by the formula HO–O–S(O)2–OH. It is one of the strongest oxidants known (E0 = +2.51 V) and is highly explosive.

<span class="mw-page-title-main">Phosphorous acid</span> Chemical compound (H3PO4)

Phosphorous acid is the compound described by the formula H3PO3. This acid is diprotic, not triprotic as might be suggested by this formula. Phosphorous acid is an intermediate in the preparation of other phosphorus compounds. Organic derivatives of phosphorous acid, compounds with the formula RPO3H2, are called phosphonic acids.

<span class="mw-page-title-main">Tantalum(V) chloride</span> Chemical compound

Tantalum(V) chloride, also known as tantalum pentachloride, is an inorganic compound with the formula TaCl5. It takes the form of a white powder and is commonly used as a starting material in tantalum chemistry. It readily hydrolyzes to form tantalum(V) oxychloride (TaOCl3) and eventually tantalum pentoxide (Ta2O5); this requires that it be synthesised and manipulated under anhydrous conditions, using air-free techniques.

(<i>E</i>)-Stilbene Chemical compound

(E)-Stilbene, commonly known as trans-stilbene, is an organic compound represented by the condensed structural formula C6H5CH=CHC6H5. Classified as a diarylethene, it features a central ethylene moiety with one phenyl group substituent on each end of the carbon–carbon double bond. It has an (E) stereochemistry, meaning that the phenyl groups are located on opposite sides of the double bond, the opposite of its geometric isomer, cis-stilbene. Trans-stilbene occurs as a white crystalline solid at room temperature and is highly soluble in organic solvents. It can be converted to cis-stilbene photochemically, and further reacted to produce phenanthrene.

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

Phosphorus pentasulfide is the inorganic compound with the formula P2S5 (empirical) or P4S10 (molecular). This yellow solid is the one of two phosphorus sulfides of commercial value. Samples often appear greenish-gray due to impurities. It is soluble in carbon disulfide but reacts with many other solvents such as alcohols, DMSO, and DMF.

<span class="mw-page-title-main">Acyloin</span> Organic compounds of the form –C(=O)C(OH)–

In organic chemistry, acyloins or α-hydroxy ketones are a class of organic compounds of the general form R−C(=O)−CR'(OH)−R", composed of a hydroxy group adjacent to a ketone group. The name acyloin is derived from the fact that they are formally derived from reductive coupling of carboxylic acyl groups. They are one of the two main classes of hydroxy ketones, distinguished by the position of the hydroxy group relative to the ketone; in this form, the hydroxy is on the alpha carbon, explaining the secondary name of α-hydroxy ketone.

<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">Hexafluorophosphate</span> Anion with the chemical formula PF6–

Hexafluorophosphate is an anion with chemical formula of [PF6]. It is an octahedral species that imparts no color to its salts. [PF6] is isoelectronic with sulfur hexafluoride, SF6, and the hexafluorosilicate dianion, [SiF6]2−, and hexafluoroantimonate [SbF6]. In this anion, phosphorus has a valence of 5. Being poorly nucleophilic, hexafluorophosphate is classified as a non-coordinating anion.

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

Hypofluorous acid, chemical formula HOF, is the only known oxyacid of fluorine and the only known oxoacid in which the main atom gains electrons from oxygen to create a negative oxidation state. The oxidation state of the oxygen in hypofluorites is 0. It is also the only hypohalous acid that can be isolated as a solid. HOF is an intermediate in the oxidation of water by fluorine, which produces hydrogen fluoride, oxygen difluoride, hydrogen peroxide, ozone and oxygen. HOF is explosive at room temperature, forming HF and O2:

In organic chemistry, the Baudisch reaction is a process for the synthesis of nitrosophenols using metal ions. Although the products are of limited value, the reaction is of historical interest as an example of metal-promoted functionalization of aromatic substrates.

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

Methanesulfonic anhydride (Ms2O) is the acid anhydride of methanesulfonic acid. Like methanesulfonyl chloride (MsCl), it may be used to generate mesylates (methanesulfonyl esters).

The Pinnick oxidation is an organic reaction by which aldehydes can be oxidized into their corresponding carboxylic acids using sodium chlorite (NaClO2) under mild acidic conditions. It was originally developed by Lindgren and Nilsson. The typical reaction conditions used today were developed by G. A. Kraus. H.W. Pinnick later demonstrated that these conditions could be applied to oxidize α,β-unsaturated aldehydes. There exist many different reactions to oxidize aldehydes, but only a few are amenable to a broad range of functional groups. The Pinnick oxidation has proven to be both tolerant of sensitive functionalities and capable of reacting with sterically hindered groups. This reaction is especially useful for oxidizing α,β-unsaturated aldehydes, and another one of its advantages is its relatively low cost.

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

Trifluoroperacetic acid is an organofluorine compound, the peroxy acid analog of trifluoroacetic acid, with the condensed structural formula CF
3
COOOH
. It is a strong oxidizing agent for organic oxidation reactions, such as in Baeyer–Villiger oxidations of ketones. It is the most reactive of the organic peroxy acids, allowing it to successfully oxidise relatively unreactive alkenes to epoxides where other peroxy acids are ineffective. It can also oxidise the chalcogens in some functional groups, such as by transforming selenoethers to selones. It is a potentially explosive material and is not commercially available, but it can be quickly prepared as needed. Its use as a laboratory reagent was pioneered and developed by William D. Emmons.

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

Mesitol (2,4,6-trimethylphenol) is an organic compound with the formula (CH3)3C6H2OH. It is one of several isomers of trimethylphenol. The name and structure of mesitol derives from the combination of mesitylene and phenol.

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

Peroxydiphosphoric acid (H4P2O8) is an oxyacid of phosphorus. Its salts are known as peroxydiphosphates. It is one of two peroxyphosphoric acids, along with peroxymonophosphoric acid.

References

  1. Schmidlin, Julius; Massini, Paul (1910). "Phosphormonopersäure und Überphosphorsäure". Ber. Dtsch. Chem. Ges. 43 (1): 1162–1171. doi:10.1002/cber.191004301195.
  2. Toennies, Gerrit (1937). "A New Method for the Preparation of Permonophosphoric Acid". J. Am. Chem. Soc. 59 (3): 555–557. doi:10.1021/ja01282a037.
  3. 1 2 Jakob, Harald; Leininger, Stefan; Lehmann, Thomas; Jacobi, Sylvia; Gutewort, Sven (2007). "Peroxo Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a19_177.pub2. ISBN   978-3527306732.
  4. 1 2 Zhu, Tian; Chang, Hou-Min; Kadia, John F. (2003). "A New Method for the Preparation of Peroxymonophosphoric Acid". Can. J. Chem. 81 (2): 156–160. doi:10.1139/v03-010.
  5. 1 2 3 Harald, Jakob; Leininger, Stefan; Lehmann, Thomas; Jacobi, Sylvia; Gutewort, Sven (2007). "Peroxo Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry . Wiley‐VCH Verlag. pp. 310–311. doi:10.1002/14356007.a19_177.pub2. ISBN   9783527306732.
  6. 1 2 3 Rao, A. Somasekar; Mohan, H. Rama (2001). "Monoperoxyphosphoric Acid". Encyclopedia of Reagents for Organic Synthesis . John Wiley & Sons. doi:10.1002/047084289X.rm287m. ISBN   9780470842898.
  7. 1 2 Battaglia, Charles J.; Edwards, John O. (1965). "The Dissociation Constants and the Kinetics of Hydrolysis of Peroxymonophosphoric Acid". Inorg. Chem. 4 (4): 552–558. doi:10.1021/ic50026a024.
  8. Ogata, Yoshiro; Tomizawa, Kohtaro; Ikeda, Toshiyuki (1979). "Oxidation of trans-Stilbene with Peroxymonophosphoric Acid". J. Org. Chem. 44 (14): 2362–2364. doi:10.1021/jo01328a006.
  9. Ogata, Yoshiro; Sawaki, Yasuhiko; Ohno, Takashi (1982). "Mechanism for Oxidation of Phenylacetylenes with Peroxymonophosphoric acid. Oxirene as an Intermediate Inconvertible to Ketocarbene". J. Am. Chem. Soc. 104 (1): 216–219. doi:10.1021/ja00365a039.
  10. Ogata, Yoshiro; Sawaki, Yasuhiko; Tomizawa, Kohtaro; Ohno, Takashi (1981). "Aromatic Hydroxylation with Peroxymonophosphoric Acid". Tetrahedron . 37 (8): 1485–1486. doi:10.1016/S0040-4020(01)92087-3.
  11. Ogata, Yoshiro; Tomizawa, Kohtaro; Ikeda, Toshiyuki (1978). "Kinetics of the Baeyer-Villiger Reaction of Acetophenones with Permonophosphoric Acid". J. Org. Chem. 43 (12): 2417–2419. doi:10.1021/jo00406a025.
  12. Ogata, Yoshiro; Tomizawa, Kohtaro; Morikawa, Takashi (1979). "Kinetics of the Peroxymonophosphoric Acid Oxidation of Aromatic Amines". J. Org. Chem. 44 (3): 352–355. doi:10.1021/jo01317a009.