Details
| Original language | English |
|---|---|
| Article number | 4469 |
| Journal | MOLECULES |
| Volume | 28 |
| Issue number | 11 |
| Publication status | Published - 31 May 2023 |
Abstract
Etidronic acid (1-Hydroxyethylidene-1,1-diphosphonic acid, HEDP, H4L) is a proposed decorporation agent for U(VI). This paper studied its complex formation with Eu(III), an inactive analog of trivalent actinides, over a wide pH range, at varying metal-to-ligand ratios (M:L) and total concentrations. Combining spectroscopic, spectrometric, and quantum chemical methods, five distinct Eu(III)−HEDP complexes were found, four of which were characterized. The readily soluble EuH2L+ and Eu(H2L)2− species with log β values of 23.7 ± 0.1 and 45.1 ± 0.9 are formed at acidic pH. At near-neutral pH, EuHL0s forms with a log β of ~23.6 and, additionally, a most probably polynuclear complex. The readily dissolved EuL− species with a log β of ~11.2 is formed at alkaline pH. A six-membered chelate ring is the key motif in all solution structures. The equilibrium between the Eu(III)–HEDP species is influenced by several parameters, i.e., pH, M:L, total Eu(III) and HEDP concentrations, and time. Overall, the present work sheds light on the very complex speciation in the HEDP–Eu(III) system and indicates that, for risk assessment of potential decorporation scenarios, side reactions of HEDP with trivalent actinides and lanthanides should also be taken into account.
Keywords
- ATR-FT-IR, complexation, DFT, ESI-MS, lanthanides, NMR, speciation, TRLFS
ASJC Scopus subject areas
- Chemistry(all)
- Analytical Chemistry
- Chemistry(all)
- Chemistry (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Molecular Medicine
- Pharmacology, Toxicology and Pharmaceutics(all)
- Pharmaceutical Science
- Pharmacology, Toxicology and Pharmaceutics(all)
- Drug Discovery
- Chemistry(all)
- Physical and Theoretical Chemistry
- Chemistry(all)
- Organic Chemistry
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: MOLECULES, Vol. 28, No. 11, 4469, 31.05.2023.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Europium(III) Meets Etidronic Acid (HEDP)
T2 - A Coordination Study Combining Spectroscopic, Spectrometric, and Quantum Chemical Methods
AU - Heller, Anne
AU - Senwitz, Christian
AU - Foerstendorf, Harald
AU - Tsushima, Satoru
AU - Holtmann, Linus
AU - Drobot, Björn
AU - Kretzschmar, Jerome
N1 - Funding Information: This work is funded by the German Federal Ministry of Education and Research (BMBF) under grant number 02NUK057B and is part of the joint project RADEKOR. L.H. acknowledges funding received from BMBF, grant number 02NUK057D, and J.K. acknowledges funding received from the German Federal Ministry for the Environment, Nature Conversation, Nuclear Safety and Consumer Protection (BMUV) within the GRaZ II project, grant number 02E11860B.
PY - 2023/5/31
Y1 - 2023/5/31
N2 - Etidronic acid (1-Hydroxyethylidene-1,1-diphosphonic acid, HEDP, H4L) is a proposed decorporation agent for U(VI). This paper studied its complex formation with Eu(III), an inactive analog of trivalent actinides, over a wide pH range, at varying metal-to-ligand ratios (M:L) and total concentrations. Combining spectroscopic, spectrometric, and quantum chemical methods, five distinct Eu(III)−HEDP complexes were found, four of which were characterized. The readily soluble EuH2L+ and Eu(H2L)2− species with log β values of 23.7 ± 0.1 and 45.1 ± 0.9 are formed at acidic pH. At near-neutral pH, EuHL0s forms with a log β of ~23.6 and, additionally, a most probably polynuclear complex. The readily dissolved EuL− species with a log β of ~11.2 is formed at alkaline pH. A six-membered chelate ring is the key motif in all solution structures. The equilibrium between the Eu(III)–HEDP species is influenced by several parameters, i.e., pH, M:L, total Eu(III) and HEDP concentrations, and time. Overall, the present work sheds light on the very complex speciation in the HEDP–Eu(III) system and indicates that, for risk assessment of potential decorporation scenarios, side reactions of HEDP with trivalent actinides and lanthanides should also be taken into account.
AB - Etidronic acid (1-Hydroxyethylidene-1,1-diphosphonic acid, HEDP, H4L) is a proposed decorporation agent for U(VI). This paper studied its complex formation with Eu(III), an inactive analog of trivalent actinides, over a wide pH range, at varying metal-to-ligand ratios (M:L) and total concentrations. Combining spectroscopic, spectrometric, and quantum chemical methods, five distinct Eu(III)−HEDP complexes were found, four of which were characterized. The readily soluble EuH2L+ and Eu(H2L)2− species with log β values of 23.7 ± 0.1 and 45.1 ± 0.9 are formed at acidic pH. At near-neutral pH, EuHL0s forms with a log β of ~23.6 and, additionally, a most probably polynuclear complex. The readily dissolved EuL− species with a log β of ~11.2 is formed at alkaline pH. A six-membered chelate ring is the key motif in all solution structures. The equilibrium between the Eu(III)–HEDP species is influenced by several parameters, i.e., pH, M:L, total Eu(III) and HEDP concentrations, and time. Overall, the present work sheds light on the very complex speciation in the HEDP–Eu(III) system and indicates that, for risk assessment of potential decorporation scenarios, side reactions of HEDP with trivalent actinides and lanthanides should also be taken into account.
KW - ATR-FT-IR
KW - complexation
KW - DFT
KW - ESI-MS
KW - lanthanides
KW - NMR
KW - speciation
KW - TRLFS
UR - http://www.scopus.com/inward/record.url?scp=85161638522&partnerID=8YFLogxK
U2 - 10.3390/molecules28114469
DO - 10.3390/molecules28114469
M3 - Article
AN - SCOPUS:85161638522
VL - 28
JO - MOLECULES
JF - MOLECULES
SN - 1420-3049
IS - 11
M1 - 4469
ER -