Stability constants of europium complexes with a nitrogen heterocycle substituted methane-1,1-diphosphonic acid
Even in moderately acidic solutions ([H{sup +}] > 0.01 M), N-piperidinomethane-1,1-diphosphonic acid (H{sub 4}PMDPA) is a strong complexant of trivalent lanthanide ions that shows enhanced complex solubility over previously studied 1,1-diphosphonic acids. The protonation constants of PMDPA in 2.0 M H/NaClO{sub 4} were determined by potentiometric and NMR titrations, and the stability constants for formation of complexes with Eu{sup 3+} were determined by solvent extraction. Difference in protonation equilibria induced by addition of the nitrogen heterocycle results in an increase in the complexation strength of PMDPA. In solutions containing 0.1 M H{sup +} and ligand concentrations greater than 0.02 M, PMDPA is the most effective 1,1-diphosphonic acid for europium complexation studied thus far.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-31-109-ENG-38
- OSTI ID:
- 242692
- Report Number(s):
- ANL/CHM/CP-89020; CONF-960796-3; ON: DE96011158; TRN: 96:014553
- Resource Relation:
- Conference: RERC-21: 21. rare earth research conference, Duluth, MN (United States), 7-12 Jul 1996; Other Information: PBD: [1996]
- Country of Publication:
- United States
- Language:
- English
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