digplanet beta 1: Athena
Share digplanet:


Applied sciences






















General ester of phosphonic acid.

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). Bisphosphonates are popular drugs for treatment of osteoporosis.[1]

Clodronic acid is a bisphosphonate used as a drug to treat osteoporosis.

Basic properties[edit]

Phophonates feature tetrahedral phosphorus centers. They are structurally closely related to (and often prepared from) phosphorous acid.[2]

Phosphonic acids and derivatives are chemically and structurally related to phosphorous acid.

Phosphonate salts are the result of deprotonation of phosphonic acids, which are diprotic acids:

RPO(OH)2 + NaOH → H2O + RPO(OH)(ONa) (monosodium phosphonate)
RPO(OH)(ONa) + NaOH → H2O + RPO(ONa)2 (disodium phosphonate)

Phosphonate esters are the result of condensation of phosphonic acids with alcohols.


Several methods exist for the preparation of phosphonic acids and its salts. Most processes begin with phosphorous acid (aka phosphorous acid, H3PO3), exploiting its reactive P-H bond.[1][2]

Phosphonic acid can be alkylated under Mannich conditions to give aminomethylated phosphonates, which are useful as complexants. One example is the industrial preparation of nitrilotris(methylenephosphonic acid:

NH3 + 3 H3PO3 + 3 CH2O → N(CH2PO3H2)3 + 3 H2O

Phosphonic acid also can be alkylated with acrylic acid derivatives to afford carboxyl functionalized phosphonic acids. This reaction is a variant of the Michael addition:

CH2=CHCO2R + 3 H3PO3 → (HO)2P(O)CH2CH2CO2R

Phosphonic esters are prepared using the Michaelis–Arbuzov reaction. For example, methyl iodide catalyses the conversion of trimethylphosphite to the phosphonate ester dimethyl methylphosphonate:

P(OMe)3 → MePO(OMe)2

These esters can be hydrolysed to the acid (Me = methyl):

MePO(OMe)2 + H2O → MePO(OH)2 + 2 MeOH

In the Michaelis–Becker reaction, a hydrogen phosphonate diester is first deprotonated and the resulting anion is alkylated.


Bisphosphonates were first synthesized in 1897 by Von Baeyer and Hofmann. An example of such a bisphosphonate is HEDP (Etidronic acid or Didronel), that is 1-hydroxyethane-1,1-diphosphonic acid, which is prepared from phosphorous acid and acetic anhydride:[1]

2 H3PO3 + (CH3CO)2O → CH3C(OH)(PO3H2)2 + CH3CO2H

Occurrence in nature[edit]

Glyphosate, the herbicide "Roundup", is a phosphonate.
2-aminoethylphosphonic acid: the first identified natural phosphonate.

Phosphonates are one of the three sources of phosphate intake in biological cells.[citation needed] The other two are inorganic phosphate and organophosphates.

The naturally-occurring phosphonate 2-aminoethylphosphonic acid was first identified in 1959 in plants and many animals, where it is localized in membranes. Phosphonates are quite common among different organisms, from prokaryotes to eubacteria and fungi, mollusks, insects and others. They were first reported in natural soils by Newman and Tate (1980). The biological role of the natural phosphonates is still poorly understood. Bis- or polyphosphonates have not been found to occur naturally.


In 1998 the consumption of phosphonates was 56,000 tons worldwide - 40,000 tons in the US, 15,000 tons in Europe and less than 800 tons in Japan. The demand of phosphonates grows steadily at 3% annually.

Metal chelants[edit]

Since the work of Schwarzenbach in 1949, phosphonic acids are known as effective chelating agents. The introduction of an amine group into the molecule to obtain -NH2-C-PO(OH)2 increases the metal binding abilities of the phosphonate. Examples for such compounds are NTMP, EDTMP and DTPMP. These phosphonates are the structural analogues to the well-known aminopolycarboxylate such as EDTA. The stability of the metal complexes increases with increasing number of phosphonic acid groups. Phosphonates are highly water-soluble while the phosphonic acids are only sparingly so.

Phosphonates are effective chelating agents. That is, they bind tightly to di- and trivalent metal ions, which is useful in water softening. In this way, they prevent formation of insoluble precipitates (scale). The binding of these ligands also suppresses the catalytic properties of metal ions. They are stable under harsh conditions. For these reasons, an important industrial use of phosphonates is in cooling waters, desalination systems, and in oil fields to inhibit scale formation. Phosphonates are also regularly used in reverse osmosis systems as anti-scalants. Phosphonates in cooling water systems also serve to control corrosion of iron and steel. In pulp and paper manufacturing and in textile industry they serve as "peroxide bleach stabilizers," by chelating metals that could inactivate the peroxide. In detergents they are used as a combination of chelating agent, scale inhibitor, and bleach stabilizer. Phosphonates are also increasingly used in medicine to treat disorders associated with bone formation and calcium metabolism. Furthermore they serve as carriers for radionuclides in bone cancer treatments (see Samarium-153-ethylene diamine tetramethylene phosphonate).


In medicine, phosphonates and bisphosphonates are commonly used as inhibitors of enzymes which utilize phosphates and diphosphates as substrates. Most notably, these enzymes include those that produce the intermediates of cholesterol biosynthesis. [3]

Niche uses[edit]

In organic synthesis, phosphonates are used in the Horner-Wadsworth-Emmons reaction. In conjunction with organosilicates, phosphonates are also used to treat "sudden oak death", which is caused by the fungus-like eukaryote Phytophthora ramorum.


The toxicity of phosphonates to aquatic organisms is low. Reported values for 48 h LC50 values for fish are between 0.1 and 1.1 mM. Also the bioconcentration factor for fish is very low.


In nature bacteria play a major role in the degradation of phosphonates.[4] Due to the presence of natural phosphonates in the environment, bacteria have evolved the ability to metabolize phosphonates as nutrient sources. Some bacteria use phosphonates as a phosphorus source for growth. Aminophosphonates can also be used as sole nitrogen source by some bacteria. The polyphosphonates used in industry differ greatly from natural phosphonates such as 2-aminoethylphosphonic acid, because they are much larger, carry a high negative charge and are complexed with metals. Biodegradation tests with sludge from municipal sewage treatment plants with HEDP and NTMP showed no indication for any degradation. An investigation of HEDP, NTMP, EDTMP and DTPMP in standard biodegradation tests also failed to identify any biodegradation. It was noted, however, that in some tests due to the high sludge to phosphonate ratio, removal of the test substance from solution observed as loss of DOC was observed. This factor was attributed to adsorption rather than biodegradation. However, bacterial strains capable of degrading aminopolyphosphonates and HEDP under P-limited conditions have been isolated from soils, lakes, wastewater, activated sludge and compost.

"No biodegradation of phosphonates during water treatment is observed but photodegradation of the Fe(III)-complexes is rapid. Aminopolyphosphonates are also rapidly oxidized in the presence of Mn(II) and oxygen and stable breakdown products are formed that have been detected in wastewater. The lack of information about phosphonates in the environment is linked to analytical problems of their determination at trace concentrations in natural waters. Phosphonates are present mainly as Ca and Mg-complexes in natural waters and therefore do not affect metal speciation or transport."[5] Phosphonates interact strongly with some surfaces, which results in a significant removal in technical and natural systems.

Phosphonate compounds[edit]

  • AEPn: Aminomethylphosphonic acid, degradation product of Round-up
  • DMMP: Dimethyl methylphosphonate, one of the simplest phosphonate diesters
  • HEDP: 1-Hydroxyethylidene-1,1-diphosphonic acid, used in detergents, water treatment, cosmetics and pharmaceuticals
  • ATMP: Amino tris(methylenephosphonic acid), chelating agent
  • EDTMP: Ethylenediamine tetra(methylene phosphonic acid), chelating agent
  • TDTMP: Tetramethylenediamine tetra(methylene phosphonic acid), chelating agent
  • HDTMP: Hexamethylenediamine tetra(methylene phosphonic acid), chelating agent
  • DTPMP: Diethylenetriamine penta(methylene phosphonic acid), chelating agent
  • PBTC: Phosphonobutane-tricarboxylic acid
  • PMIDA: N-(phosphonomethyl)iminodiacetic acid
  • CEPA: 2-carboxyethyl phosphonic acid
  • HPAA: 2-Hydroxyphosphonocarboxylic acid
  • AMP: Amino-tris-(methylene-phosphonic acid)
  • BPMG: N,N-Bis(phosphonomethyl)glycine
  • Glyphosate, a common agricultural herbicide
  • Foscarnet, for treatment of herpes
  • Perzinfotel, for treatment of stroke
  • Di-(2-ethylhexyl)phosphoric acid, extractant for uranium

See also[edit]


  1. ^ a b c Svara, J.; Weferling, N.; Hofmann, T. "Phosphorus Compounds, Organic," In 'Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2008. doi:10.1002/14356007.a19_545.pub2.
  2. ^ a b Modern Phosphonate Chemistry By Philippe Savignac and Bogdan Iorga, CRC Press,  Boca Raton, FL. 2003. ISBN 0-8493-1099-7.
  3. ^ Wiemer, AJ; Hohl, RJ; Wiemer, DF (June 2009). "The intermediate enzymes of isoprenoid metabolism as anticancer targets.". Anti-cancer agents in medicinal chemistry 9 (5): 526–42. PMID 19519294. 
  4. ^ Huang J, Su Z, Xu Y (November 2005). "The evolution of microbial phosphonate degradative pathways". Journal of Molecular Evolution 61 (5): 682–90. doi:10.1007/s00239-004-0349-4. PMID 16245012. 
  5. ^ Nowack, Bernd "Environmental chemistry of phosphonates" Water Research 2003, vol. 37, p 2533-2546 .doi:10.1016/S0043-1354(03)00079-4

Additional reading[edit]

Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Phosphonate — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.
132 videos foundNext > 

Review of Phosphonate Synthesis in Chemistry : Studying Chemistry

Subscribe Now: http://www.youtube.com/subscription_center?add_user=ehoweducation Watch More: http://www.youtube.com/ehoweducation Phosphonate synthesis in ch...

Phosphonate (OP) Test Kit - TK0159-Z

Phosphonate (OP) Test Kit - TK0159-Z: 1 drop = 0.7 ppm as HEDP Phosphonate / 10 mL AquaPhoenix Scientific Inc. 9 Barnhart Drive Hanover, PA 17331 http://www....

Testing for Phosphonate Using pH Paper and Fluoride Masking Agent (K-1583)

Root phosphonate test sample

Jerome Hardy - Primor describes the amount of root sample to take for phosphonate testing.

MCRD Phosphonate cooling tower test

Recorded using Camera Plus Pro.

Drop Test - Phosphonate (Long Method)

Drop Test - Phosphonate (Short Method)

Testing for Phosphonate in Non-Fluoridated Water (K-1584)

How to Pronounce Phosphonate

Learn how to say words in English correctly with Emma Saying free pronunciation tutorials. Over 140000 words were already uploaded... Check them out! Visit ...

Testing for Phosphonate in NonFluoridated Water Using Taylor’s K-1584

Phosphonates are widely used in industrial water treatment to inhibit scale, sequester undesirable metals, control corrosion, and to disperse particulate mat...

132 videos foundNext > 

132 news items

PR Newswire (press release)
Mon, 06 Oct 2014 09:30:00 -0700

Chelating agents are of the utmost importance in water treatment and cleaners & detergents industries. They bind and remove metal ions while at the same time play other significant roles in the process. Textiles and pulp & paper industries require ...


Wed, 07 Jan 2015 14:18:45 -0800

If phosphate discharge is prohibited, one possible alternative for cooling tower water treatment is an all-polymer program.2 A simple polymer -- often a polyacrylate -- is typically included in a phosphate/phosphonate program to act as a sequestering ...
New Jersey Law Journal
Tue, 30 Dec 2014 12:45:15 -0800

According to the complaint, the three lawyers together had “hundreds” of phosphonate cases, including “a small number” involving Actonel, “a larger amount” concerning Fosamax and “several hundred” Aredia and Zometa cases. The Actonel litigation has ...
Center for Research on Globalization
Fri, 02 Jan 2015 09:01:07 -0800

Isolation of a Pseudomonas sp. which utilizes the phosphonate herbicide glyphosate. Appl Environ Microbiol. 1983;46:316–320. [PMC free article][PubMed]. 10. Peñaloza-Vazquez A, Mena GL, Herrera-Estrella L, Bailey AM. Cloning and sequencing of the ...
Mon, 17 Nov 2014 21:19:35 -0800

Da Phosphonate aus Blattdüngern zu höheren Rückständen in bestimmten Erzeugnissen geführt haben, aber nachweislich nicht auf die Anwendung eines Pflanzenschutzmittels zurück zu führen waren, konnte erreicht werden, dass die Höchstgehalte für die ...
San Jose Mercury News
Sun, 28 Sep 2014 15:52:15 -0700

He says the late fall is the best time to apply a preventive phosphonate treatment to oaks that are at risk. Data from Garbelotto's "SOD Blitz" surveys has been digitized so it can be viewed using a free smartphone application. Users of the app can ...
GlobeNewswire (press release)
Thu, 18 Dec 2014 03:03:50 -0800

CMX157 is a novel lipid acyclic nucleoside phosphonate that delivers high intracellular concentrations of the active antiviral agent tenofovir diphosphate. CMX157 is active against HBV and more than 200-fold more potent in vitro versus tenofovir ...
Napa Valley Register
Fri, 03 Oct 2014 20:05:39 -0700

Protective phosphonate applications (AgriFos or Reliant) should be made between Halloween and Christmas. Oaks are actively absorbent in fall and they need time to build up their defenses before the spring infection period. The ongoing Blitzes continue ...

Oops, we seem to be having trouble contacting Twitter

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!

Searchlight Group

Digplanet also receives support from Searchlight Group. Visit Searchlight