A phosphite anion or phosphite in inorganic chemistry usually refers to [HPO3]2− but includes [H2PO3]− ([HPO2(OH)]−). These anions are the conjugate bases of phosphorous acid (H3PO3). The corresponding salts, e.g. sodium phosphite (Na2HPO3) are reducing in character.
The IUPAC recommended name for phosphorous acid is phosphonic acid. Correspondingly, the IUPAC-recommended name for the HPO2− 3 ion is phosphonate. In the US the IUPAC naming conventions for inorganic compounds are taught at high school, but not as a 'required' part of the curriculum.[2] A well-known university-level textbook follows the IUPAC recommendations.[3] In practice any reference to "phosphite" should be investigated to determine the naming convention being employed.
Salts containing HPO32−, called phosphonates or phosphitesedit
Structural formula of Na2HPO3. The anion has C3v symmetry.
From the commercial perspective, the most important phosphite salt is basic lead phosphite. Many salts containing the phosphite ion have been investigated structurally, these include sodium phosphite pentahydrate (Na2HPO3·5H2O). (NH4)2HPO3·H2O, CuHPO3·H2O, SnHPO3 and Al2(HPO3)3·4H2O.[4] The structure of HPO2− 3 is approximately tetrahedral.[5][6]
HPO2− 3 has a number of canonical resonance forms making it isoelectronic with bisulfite ion, HSO− 3, which has a similar structure.[7]
Salts containing HP(O)2OH−edit
Acid or hydrogen phosphites are called hydrogenphosphonates or acid phosphites. IUPAC recommends the name hydrogenphosphonates). They are anions HP(O)2OH−. Aypical derivative is the salt [NH4][HP(O)2OH].[7][6] Many related salts are known, e.g., RbHPHO3, CsHPHO3, TlHPHO3. These salts are prepared by treating phosphorous acid with the metal carbonate. These compounds contain a layer polymeric anion consisting of HPO3 tetrahedra linked by hydrogen bonds. These layers are interleaved by layers of metal cations.[8]
Organic esters of hydrogen phosphites are anions with the formula HP(O)2OR− (R = organic group). One commercial example is the fungicidefosetyl-Al with the formula [C2H5OP(H)O2]3Al.[9]
Salts containing H2P2O52−, called diphosphites or pyrophosphitesedit
Pyrophosphites (diphosphites) can be produced by gently heating acid phosphites under reduced pressure. They contain the ion H 2P 2O2− 5, which can be formulated [HP(O)2O−P(O)2H]2−.[7][6]
Parallels in arsenic chemistryedit
In contrast to the paucity of evidence for PO3− 3, the corresponding arsenic ion, ortho-arsenite, AsO3− 3 is known. An example is Ag3AsO3 as well as the polymeric meta-arsenite (AsO− 2) n.[7] The iso-electronic sulfite ion, SO2− 3 is known from its salts.[7]
Use as fungicidesedit
This section is missing information about mechanism of antifungal/antiprotozoal action. Please expand the section to include this information. Further details may exist on the talk page.(March 2022)
Inorganic phosphites (containing HPO2− 3) have been applied to crops to combat fungus-like pathogens of the order oomycetes (water molds). The situation is confusing because of the similarity in name between phosphite and phosphate (a major plant nutrient and fertilizer ingredient), and controversial because phosphites have sometimes been advertised as fertilizers, even though they are converted to phosphate too slowly to serve as a plant's main phosphorus source. In fact, phosphites may cause phytotoxicity when a plant is starved of phosphates.[10] Lemoynie[11] and others have described this complicated situation and noted that calling phosphites fertilizers avoided the regulatory complication and negative public perceptions that might have been incurred by registering them as fungicides.[10]
A major form of inorganic phosphite used in agriculture is monopotassium phosphite. This compound does serve as a potassium fertilizer.
^Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier ISBN0-12-352651-5
^"Synthesis and crystal structures of aluminum and iron phosphites", D.M. Poojary, Y. Zhang, D.E. Cox, P.R. Rudolf, S. Cheng & A. Clearfield, J. Chem. Crystallogr.24 (1994) 155–163
^L. E. Gordon, W. T. A. Harrison. "Bis(melaminium) hydrogen phosphite tetrahydrate". Acta Crystallogr.59 (2): o195–o197. doi:10.1107/S1600536803001247
^ abc"Crystal chemistry of inorganic phosphites", J. Loub, Acta Crystallogr. (1991), B47, 468–473, doi:10.1107/S0108768191002380
^"Phosphites and Phosphates: When Distributors and Growers alike could get confused!" by Jean-Pierre Leymonie. Courtesy of New Ag International, September 2007 edition.
January 01, 1970
phosphite, anion, phosphites, type, phosphite, ester, phosphite, anion, phosphite, inorganic, chemistry, usually, refers, hpo3, includes, h2po3, hpo2, these, anions, conjugate, bases, phosphorous, acid, h3po3, corresponding, salts, sodium, phosphite, na2hpo3, . For phosphites of the type P OR 3 see Phosphite ester A phosphite anion or phosphite in inorganic chemistry usually refers to HPO3 2 but includes H2PO3 HPO2 OH These anions are the conjugate bases of phosphorous acid H3PO3 The corresponding salts e g sodium phosphite Na2HPO3 are reducing in character Phosphite anion Names IUPAC name Phosphonate Systematic IUPAC name Phosphite 1 Identifiers CAS Number 14901 63 4 N 3D model JSmol Interactive imageInteractive image ChEBI CHEBI 45064 N ChEMBL ChEMBL1235376 N ChemSpider 97035 N Gmelin Reference 68617 MeSH Phosphorite PubChem CID 107908 CompTox Dashboard EPA DTXSID80164154 InChI InChI 1S O3P c1 4 2 3 q 3 NKey AQSJGOWTSHOLKH UHFFFAOYSA N N SMILES O P O O P O O O Properties Chemical formula HPO2 3 Molar mass 79 9810 g mol 1 Related compounds Other anions Phosphinite Phosphonite Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 Nomenclature 2 Salts containing HPO32 called phosphonates or phosphites 3 Salts containing HP O 2OH 4 Salts containing H2P2O52 called diphosphites or pyrophosphites 5 Parallels in arsenic chemistry 6 Use as fungicides 7 See also 8 Further reading 9 ReferencesNomenclature editThe IUPAC recommended name for phosphorous acid is phosphonic acid Correspondingly the IUPAC recommended name for the HPO2 3 ion is phosphonate In the US the IUPAC naming conventions for inorganic compounds are taught at high school but not as a required part of the curriculum 2 A well known university level textbook follows the IUPAC recommendations 3 In practice any reference to phosphite should be investigated to determine the naming convention being employed Salts containing HPO32 called phosphonates or phosphites edit nbsp Structural formula of Na2HPO3 The anion has C3v symmetry From the commercial perspective the most important phosphite salt is basic lead phosphite Many salts containing the phosphite ion have been investigated structurally these include sodium phosphite pentahydrate Na2HPO3 5H2O NH4 2HPO3 H2O CuHPO3 H2O SnHPO3 and Al2 HPO3 3 4H2O 4 The structure of HPO2 3 is approximately tetrahedral 5 6 HPO2 3 has a number of canonical resonance forms making it isoelectronic with bisulfite ion HSO 3 which has a similar structure 7 nbsp Salts containing HP O 2OH editAcid or hydrogen phosphites are called hydrogenphosphonates or acid phosphites IUPAC recommends the name hydrogenphosphonates They are anions HP O 2OH Aypical derivative is the salt NH4 HP O 2OH 7 6 Many related salts are known e g RbHPHO3 CsHPHO3 TlHPHO3 These salts are prepared by treating phosphorous acid with the metal carbonate These compounds contain a layer polymeric anion consisting of HPO3 tetrahedra linked by hydrogen bonds These layers are interleaved by layers of metal cations 8 Organic esters of hydrogen phosphites are anions with the formula HP O 2OR R organic group One commercial example is the fungicide fosetyl Al with the formula C2H5OP H O2 3Al 9 Salts containing H2P2O52 called diphosphites or pyrophosphites editPyrophosphites diphosphites can be produced by gently heating acid phosphites under reduced pressure They contain the ion H2 P2 O2 5 which can be formulated HP O 2O P O 2H 2 7 6 Parallels in arsenic chemistry editIn contrast to the paucity of evidence for PO3 3 the corresponding arsenic ion ortho arsenite AsO3 3 is known An example is Ag3AsO3 as well as the polymeric meta arsenite AsO 2 n 7 The iso electronic sulfite ion SO2 3 is known from its salts 7 Use as fungicides editThis section is missing information about mechanism of antifungal antiprotozoal action Please expand the section to include this information Further details may exist on the talk page March 2022 Inorganic phosphites containing HPO2 3 have been applied to crops to combat fungus like pathogens of the order oomycetes water molds The situation is confusing because of the similarity in name between phosphite and phosphate a major plant nutrient and fertilizer ingredient and controversial because phosphites have sometimes been advertised as fertilizers even though they are converted to phosphate too slowly to serve as a plant s main phosphorus source In fact phosphites may cause phytotoxicity when a plant is starved of phosphates 10 Lemoynie 11 and others have described this complicated situation and noted that calling phosphites fertilizers avoided the regulatory complication and negative public perceptions that might have been incurred by registering them as fungicides 10 A major form of inorganic phosphite used in agriculture is monopotassium phosphite This compound does serve as a potassium fertilizer See also editHypophosphite H2 PO 2 Organophosphorus Phosphine PH3 and the organic phosphines PR3 Phosphine oxide OPR3 Phosphinite P OR R2 Phosphonite P OR 2R Phosphinate OP OR R2 Phosphonate organic phosphonates OP OR 2R Phosphate PO3 4 Organophosphate OP OR 3Further reading editA Earnshaw Norman Greenwood 1997 The Chemistry of the Elements 2nd ed pp 513 514 References edit Phosphorite PubChem Public Chemical Database The PubChem Project USA National Center for Biotechnology Information Physical setting chemistry core curriculum The University of the State of New York The State Education Department http www p12 nysed gov ciai mst pub chemist pdf Egon Wiberg Arnold Frederick Holleman 2001 Inorganic Chemistry Elsevier ISBN 0 12 352651 5 Synthesis and crystal structures of aluminum and iron phosphites D M Poojary Y Zhang D E Cox P R Rudolf S Cheng amp A Clearfield J Chem Crystallogr 24 1994 155 163 L E Gordon W T A Harrison Bis melaminium hydrogen phosphite tetrahydrate Acta Crystallogr 59 2 o195 o197 doi 10 1107 S1600536803001247 a b c Crystal chemistry of inorganic phosphites J Loub Acta Crystallogr 1991 B47 468 473 doi 10 1107 S0108768191002380 a b c d e Greenwood Norman N Earnshaw Alan 1997 Chemistry of the Elements 2nd ed Butterworth Heinemann ISBN 978 0 08 037941 8 Kosterina EV Troyanov SI Kemnitz E Aslanov LA 2001 Synthesis and Crystal Structure of Acid Phosphites RbH2PO3 CsH2PO3 and TlH2PO3 Russian Journal of Coordination Chemistry 27 7 458 462 doi 10 1023 A 1011377229855 S2CID 91297300 Franz Muller Peter Ackermann Paul Margot 2012 Fungicides Agricultural 2 Individual Fungicides Ullmann s Encyclopedia of Industrial Chemistry Weinheim Wiley VCH doi 10 1002 14356007 o12 o06 ISBN 978 3 527 30673 2 a b Thao Yamakawa 2008 Phosphite phosphorous acid Fungicide fertilizer or bio stimulator Soil Science and Plant Nutrition 55 2 228 234 doi 10 1111 j 1747 0765 2009 00365 x S2CID 95723306 Phosphites and Phosphates When Distributors and Growers alike could get confused by Jean Pierre Leymonie Courtesy of New Ag International September 2007 edition Retrieved from https en wikipedia org w index php title Phosphite anion amp oldid 1175437957, wikipedia, wiki, book, books, library,
