Formation of soluble complexes with metal ions
From a chemical-physical point of view, Phosphonates differ from carboxylic complexing substances owing to the simultaneous presence of two negative charges on each functional unit.
This "bi-functionality" provides to each phosphonic group the capability of acting independently as sequestering agent.
From an applicational view point , this properly becomes highly important complexing agents are to be used in an oxidizing medium ( i.e.H2O2)
