Protolytic properties of aminomethylated calix[4]resorcinol, hydroxyethylidene diphosphonic acid and their composition in aqueous micellar solutions

Abstract

The constants of protolytic equilibria for hydroxyethylidene diphosphonic acid (HEDP), aminomethylated calix[4]resorcinol (AMC), and the composition based on them (AMC-HEDP) in a solution of nonionic surfactant-polyoxyethylated dodecanol Brij-35 have been determined by pH-metric titration with subsequent mathematical processing of the data. In addition to monomeric forms, the existence of several dimeric forms of different extent of protonation has been also found in the solutions of AMC and HEDP. For the composition based on AMC-HEDP in the pH range from acid to neutral, the formation of mixed forms of the following composition has been established: H16YL40, H15YL41–, H14YL42–, H13YL43–, H12YL44–, H7YL2–, H6YL22–.

Keywords

• protolytic properties
• aminomethylated calix[4]resorcinol
• hydroxyethylidene diphosphonic acid
• amc-hedp composition
• ph-metric titration