Definition of phosphonic acid in US English:

phosphonic acid


  • A crystalline acid obtained by the reaction of phosphorus trioxide with water.

    A dibasic acid; chemical formula: HPO(OH)₂

    • ‘The phosphoric or phosphonic acid ester formed with the enzyme is extremely stable and is hydrolyzed very slowly.’
    • ‘The abscission process was also induced in vivo by embrioctomy or 2-chloroethyl phosphonic acid treatment in fruitlets and by deblading in leaves.’
    • ‘A Hoffman rearrangement employing sodium hypobromite yielded the amine which was acid hydrolysed to obtain crude 2-aminoindan - 2 - phosphonic acid.’


Late 19th century: phosphonic from phospho- ‘relating to phosphorus’, on the pattern of sulphonic.


phosphonic acid

/fäsˌfänik ˈasid/