Phosphorus oxoacids: Difference between revisions
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=Phosphorous acid= | =Phosphorous acid= | ||
[[Phosphorous acid]] is sometimes called '''phosphorus acid'''. | [[Phosphorous acid]] is sometimes called '''phosphorus acid''', '''orthophosphorous acid''', or '''monophosphorous acid'''. Phosphorous acid is a minor tautomer that exists in equilibrium with [[phosphonic acid]]. Both tautomers have their own pages: [[Phosphonic acid]] and [[Phosphorous acid]], but because preparation and uses of 'phosphorous acid' actually pertain more to the major tautomer, phosphonic acid, and it is more often referred to as 'phosphorous acid', this added information can be found under [[phosphorous acid]]. Phosphorous acid has the chemical formula H<sub>3</sub>PO<sub>3</sub>, which is best expressed as P(OH)<sub>3</sub> to show its [[Acid#Polyprotic acids|triprotic]] character. P(OH)<sub>3</sub> (IUPAC: phosphorous acid) has CAS number 10294-56-1 and CID: 107909<ref name=Phosphorous>{{ cite web |title=Phosphorous acid - PubChem Public Chemical Database |url=http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=107909&loc=ec_rcs }}</ref>. It has been shown to be a stable tautomer.<ref name=Xi>{{ cite journal |title=Synthesis of molybdenum complex with novel P(OH)<sub>3</sub> ligand based on the one-pot reaction of Mo(CO)<sub>6</sub> with HP(O)(OEt)<sub>2</sub> and water |author=Xi C, Liu Y, Lai C, Zhou L |journal=Inorgn Chem Commun. |volume=7 |issue=11 |year=2004 |pages=1202-4 |doi=10.1016/j.inoche.2004.09.012 }}</ref><ref name=Sokolov>{{ cite journal |title=Stabilization of tautomeric forms P(OH)<sub>3</sub> and HP(OH)<sub>2</sub> and their derivatives by coordination to palladium and nickel atoms in heterometallic clusters with the Mo<sub>3</sub>MQ<sub>4</sub><sup>4+</sup> core (M = Ni, Pd; Q = S, Se) |author=Sokolov MN, Chubarova EV, Kovalenko KA, Mironov IV, Virovets1 AV, Peresypkina EV, Fedin VP |journal=Russ Chem Bull. |volume=54, |issue=3 |year=2005 |pages=615-22 |doi=10.1007/s11172-005-0296-1 }}</ref> | ||
Diphosphorous acid is made by condensation: | |||
2P(OH)<sub>3</sub> <=> (OH)<sub>2</sub>POP(OH)<sub>2</sub> + H<sub>2</sub>0 | |||
For phosphorous acid, an '''oligophosphorous acid''' refers to a few molecules condensed into a molecule with the loss of H<sub>2</sub>O as each unit of P(OH)<sub>3</sub> is added on. The general formula is | |||
(HO)<sub>2</sub>PO[P(OH)O]<sub>n-2</sub>P(OH)<sub>2</sub>, | |||
where n = 2, 3, 4, etc., oligo-. Here as with [[phosphonic acid]] the repeat unit is (HPO<sub>2</sub>)<sub>n-2</sub>. | |||
[[Image:Phosphorous Acids.jpg|thumb|left ]] | |||
A '''polyphosphorous acid''' can have dozens of units condensed in a row. Regardless of the value of n, both polyphosphorous acid and polyphosphonic acid have the same chemical formula for any specific n, e.g., triphosphosphonic acid is H<sub>5</sub>P<sub>3</sub>O<sub>7</sub> and triphosphorous acid is H<sub>5</sub>P<sub>3</sub>O<sub>7</sub> for n=3. | |||
In oligophosphorous acids of sufficient size, there are multiple OH that can result in the condensation of a '''cyclophosphorous acid''' that does not have multiple (HPO<sub>3</sub>) [[Phosphoric acids and phosphates#Cyclo- or metaphosphoric acids and metaphosphates|metaphosphoric acid]] units. | |||
However, the usual referral to a cyclophosphorous acid (cyclophosphites) may be misnomers wherein the cyclic portion is carbon-based with a phosphorous acid side chain of one or more molecules, or one or a limited number of either of the two tautomers included in the ring but as a minority contributor. For example the effect of varying ring size on the phosphonate-phosphite tautomerism of cyclophosphorous acids has been shown.<ref name=Gladyshev>{{ cite journal |author=Gladyshev EN, Bayushkin PY, Sokolov VS |title=Some one-electron oxidation reactions of biheteroorganic derivatives with Ge-Hg and Ge-Li groupings |journal=Russ Chem Bull. |volume=27 |issue=3 |month=Mar |year=1978 |pages=592-5 |doi=10.1007/BF00923949 }}</ref> But the cyclophosphorous acids are biheteroorganic. | |||
Branching can also occur in either oligophosphorous or polyphosphorous acid. These are '''ultraoligophosphorous''' or '''ultrapolyphosphorous''' acids, or ultraoligophosphites and ultrapolyphosphites, respectively. | |||
=Phosphoric acid= | |||
'''Phosphoric acid''' or '''orthophosphoric acid''' has its own page: [[Phosphoric acid]]. Other acids commonly called 'phosphoric acid' are on page: [[Phosphoric acids and phosphates]]. | |||
=References= | =References= | ||
Revision as of 22:48, 24 March 2009
Editor-In-Chief: Henry A. Hoff
Overview
Phosphorus forms a variety of compounds with oxygen and a number of these fit the description of an oxoacid. A phosphorus oxoacid contains phosphorus and oxygen, at least one hydrogen atom bound to oxygen, and forms an ion by the loss of one or more protons.
Phosphenous acid
Phosphenous acid (HOPO) is structurally based on σ2λ3 phosphorus.[1] CID 22497.[2] With only one hydroxyl radical per molecule, phosphenous acid can form the dimer, diphosphenous acid, with the release of one H2O. But, phosphenous acid does not yield H2O when it forms an oligomer with more molecules than diphosphenous acid. Instead the double bonded oxygen is shared with the adjacent phosphorus atom. In this way phosphenous acid can form polymers, including cyclic, cyclooligophosphenous acid, and branched, ultraoligophosphenous acid. An easily obtained cyclic trimer of phosphenous acid is composed of (HOPO)x repeat units where x=3, and OH is replaced by 2,6-di-tert-butyl-4-methylphenyl (Ar).[3]
Phosphinic acid
Phosphinic acid, HOP(O)H2, is a tautomer that exists in equilibrium with the minor tautomer hypophosphorous acid, HP(OH)2. Phosphinic acid is CID 6326996, H2O2P+.[4] Both tautomers are described on the same page: Hypophosphorous acid. Usually, hypo and ous when added signify that the acid contains two less oxygen atoms than the "ic", phosphoric acid. Phosphinic acid is monoprotic as highlighted by its formula written as HOP(O)H2 and monobasic. Salts derived from these acids are called phosphinates or hypophosphites.
Phosphorous acid
Phosphorous acid is sometimes called phosphorus acid, orthophosphorous acid, or monophosphorous acid. Phosphorous acid is a minor tautomer that exists in equilibrium with phosphonic acid. Both tautomers have their own pages: Phosphonic acid and Phosphorous acid, but because preparation and uses of 'phosphorous acid' actually pertain more to the major tautomer, phosphonic acid, and it is more often referred to as 'phosphorous acid', this added information can be found under phosphorous acid. Phosphorous acid has the chemical formula H3PO3, which is best expressed as P(OH)3 to show its triprotic character. P(OH)3 (IUPAC: phosphorous acid) has CAS number 10294-56-1 and CID: 107909[5]. It has been shown to be a stable tautomer.[6][7]
Diphosphorous acid is made by condensation:
2P(OH)3 <=> (OH)2POP(OH)2 + H20
For phosphorous acid, an oligophosphorous acid refers to a few molecules condensed into a molecule with the loss of H2O as each unit of P(OH)3 is added on. The general formula is
(HO)2PO[P(OH)O]n-2P(OH)2,
where n = 2, 3, 4, etc., oligo-. Here as with phosphonic acid the repeat unit is (HPO2)n-2.
A polyphosphorous acid can have dozens of units condensed in a row. Regardless of the value of n, both polyphosphorous acid and polyphosphonic acid have the same chemical formula for any specific n, e.g., triphosphosphonic acid is H5P3O7 and triphosphorous acid is H5P3O7 for n=3.
In oligophosphorous acids of sufficient size, there are multiple OH that can result in the condensation of a cyclophosphorous acid that does not have multiple (HPO3) metaphosphoric acid units.
However, the usual referral to a cyclophosphorous acid (cyclophosphites) may be misnomers wherein the cyclic portion is carbon-based with a phosphorous acid side chain of one or more molecules, or one or a limited number of either of the two tautomers included in the ring but as a minority contributor. For example the effect of varying ring size on the phosphonate-phosphite tautomerism of cyclophosphorous acids has been shown.[8] But the cyclophosphorous acids are biheteroorganic.
Branching can also occur in either oligophosphorous or polyphosphorous acid. These are ultraoligophosphorous or ultrapolyphosphorous acids, or ultraoligophosphites and ultrapolyphosphites, respectively.
Phosphoric acid
Phosphoric acid or orthophosphoric acid has its own page: Phosphoric acid. Other acids commonly called 'phosphoric acid' are on page: Phosphoric acids and phosphates.
References
- ↑ Ronald Stanley Edmundson (1988). Dictionary of Organophosphorus Compounds. CRC Press. p. 1347. ISBN 0412257904, 9780412257902 Check
|isbn=value: invalid character (help). Text "page xi " ignored (help) - ↑ "Phosphenous acid - PubChem Public Chemical Database".
- ↑ Quin LD, Jankowski S, Rudzinski J, Sommese AG, Wu XP (1993). "Experiments on the generation of 2-coordinate phosphoryl species by fragmentation of 7-phosphanorbornene and 3-phospholene derivatives". J Org Chem. 58 (23): 6212–6. doi:10.1021/jo00075a014. Unknown parameter
|month=ignored (help) - ↑ "Phosphinic acid - PubChem Public Chemical Database".
- ↑ "Phosphorous acid - PubChem Public Chemical Database".
- ↑ Xi C, Liu Y, Lai C, Zhou L (2004). "Synthesis of molybdenum complex with novel P(OH)3 ligand based on the one-pot reaction of Mo(CO)6 with HP(O)(OEt)2 and water". Inorgn Chem Commun. 7 (11): 1202–4. doi:10.1016/j.inoche.2004.09.012.
- ↑ Sokolov MN, Chubarova EV, Kovalenko KA, Mironov IV, Virovets1 AV, Peresypkina EV, Fedin VP (2005). "Stabilization of tautomeric forms P(OH)3 and HP(OH)2 and their derivatives by coordination to palladium and nickel atoms in heterometallic clusters with the Mo3MQ44+ core (M = Ni, Pd; Q = S, Se)". Russ Chem Bull. 54, (3): 615–22. doi:10.1007/s11172-005-0296-1.
- ↑ Gladyshev EN, Bayushkin PY, Sokolov VS (1978). "Some one-electron oxidation reactions of biheteroorganic derivatives with Ge-Hg and Ge-Li groupings". Russ Chem Bull. 27 (3): 592–5. doi:10.1007/BF00923949. Unknown parameter
|month=ignored (help)