skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Coordination Chemistry and f-Element Complexation by Diethylenetriamine- N, N"bis(acetylglycine)- N, N', N"-triacetic Acid

Abstract

Here, potentiometric and spectroscopic techniques were used to evaluate the coordination behavior and thermodynamic features of trivalent f-element complexation by diethylenetriamine- N,N"-bis(acetylglycine)- N,N',N"-triacetic acid (DTTA-DAG) and its di(acetylglycine ethyl ester) analogue [diethylenetriamine- N,N"-bis(acetylglycine ethyl ester)- N,N',N"-triacetic acid (DTTA-DAGEE)]. Protonation constants and stability constants of trivalent lanthanide complexes (except Pm 3+) were determined by potentiometry. Six protonation sites and three metal–ligand complexes [ML 2–, MHL , and MH 2L(aq)] were quantified for DTTA-DAG. Four protonation sites and one metal–ligand complex [ML(aq)] were observed for DTTA-DAGEE, consistent with the presence of two ester groups. Absorption spectroscopy was utilized to measure the stability constants for complexation of trivalent neodymium and americium by DTTA-DAG and trivalent neodymium by DTTA-DAGEE. The coordination environment of trivalent europium in the presence of DTTA-DAG was investigated at various acidities by luminescence lifetime measurements. Decay constants indicate one water molecule in the inner coordination sphere across the 1.0 < pH < 5.5 range, presumably due to octadentate coordination by DTTA-DAG. A trans-lanthanide pattern of complex stabilities for DTTA-DAG was found to be analogous to that observed for DTPA, with a ~10 6 reduction of the complex stability. The lessened strength of complexation, relative to DTPA, was attributed to significantmore » reduction of the total ligand basicity for DTTA-DAG due to the electronic influence of amide functionalization. When DTTA-DAG is used as an aqueous holdback complexant in liquid–liquid distribution experiments, the preferential coordination of Am 3+ in the aqueous environment offers efficient An/Ln differentiation. The separation extends to pH 2 conditions, where the kinetics of phase transfer in such liquid–liquid systems are aided by the acid-catalyzed dissociation of a metal/aminopolycarboxylate complex.« less

Authors:
 [1];  [1];  [1]
  1. Idaho National Lab. (INL), Idaho Falls, ID (United States). Aqueous Separations and Radiochemistry Dept.
Publication Date:
Research Org.:
Idaho National Lab. (INL), Idaho Falls, ID (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
1407422
Report Number(s):
INL/JOU-16-39809
Journal ID: ISSN 0020-1669
Grant/Contract Number:  
AC07-05ID14517
Resource Type:
Accepted Manuscript
Journal Name:
Inorganic Chemistry
Additional Journal Information:
Journal Volume: 55; Journal Issue: 21; Journal ID: ISSN 0020-1669
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Actinide; ALSEP; Complexes; Coordination; DTPA; Lanthanide; Separations; TALSPEAK

Citation Formats

Heathman, Colt R., Grimes, Travis S., and Zalupski, Peter R. Coordination Chemistry and f-Element Complexation by Diethylenetriamine-N,N"bis(acetylglycine)-N,N',N"-triacetic Acid. United States: N. p., 2016. Web. doi:10.1021/acs.inorgchem.6b02158.
Heathman, Colt R., Grimes, Travis S., & Zalupski, Peter R. Coordination Chemistry and f-Element Complexation by Diethylenetriamine-N,N"bis(acetylglycine)-N,N',N"-triacetic Acid. United States. doi:10.1021/acs.inorgchem.6b02158.
Heathman, Colt R., Grimes, Travis S., and Zalupski, Peter R. Thu . "Coordination Chemistry and f-Element Complexation by Diethylenetriamine-N,N"bis(acetylglycine)-N,N',N"-triacetic Acid". United States. doi:10.1021/acs.inorgchem.6b02158. https://www.osti.gov/servlets/purl/1407422.
@article{osti_1407422,
title = {Coordination Chemistry and f-Element Complexation by Diethylenetriamine-N,N"bis(acetylglycine)-N,N',N"-triacetic Acid},
author = {Heathman, Colt R. and Grimes, Travis S. and Zalupski, Peter R.},
abstractNote = {Here, potentiometric and spectroscopic techniques were used to evaluate the coordination behavior and thermodynamic features of trivalent f-element complexation by diethylenetriamine-N,N"-bis(acetylglycine)-N,N',N"-triacetic acid (DTTA-DAG) and its di(acetylglycine ethyl ester) analogue [diethylenetriamine-N,N"-bis(acetylglycine ethyl ester)-N,N',N"-triacetic acid (DTTA-DAGEE)]. Protonation constants and stability constants of trivalent lanthanide complexes (except Pm3+) were determined by potentiometry. Six protonation sites and three metal–ligand complexes [ML2–, MHL–, and MH2L(aq)] were quantified for DTTA-DAG. Four protonation sites and one metal–ligand complex [ML(aq)] were observed for DTTA-DAGEE, consistent with the presence of two ester groups. Absorption spectroscopy was utilized to measure the stability constants for complexation of trivalent neodymium and americium by DTTA-DAG and trivalent neodymium by DTTA-DAGEE. The coordination environment of trivalent europium in the presence of DTTA-DAG was investigated at various acidities by luminescence lifetime measurements. Decay constants indicate one water molecule in the inner coordination sphere across the 1.0 < pH < 5.5 range, presumably due to octadentate coordination by DTTA-DAG. A trans-lanthanide pattern of complex stabilities for DTTA-DAG was found to be analogous to that observed for DTPA, with a ~106 reduction of the complex stability. The lessened strength of complexation, relative to DTPA, was attributed to significant reduction of the total ligand basicity for DTTA-DAG due to the electronic influence of amide functionalization. When DTTA-DAG is used as an aqueous holdback complexant in liquid–liquid distribution experiments, the preferential coordination of Am3+ in the aqueous environment offers efficient An/Ln differentiation. The separation extends to pH 2 conditions, where the kinetics of phase transfer in such liquid–liquid systems are aided by the acid-catalyzed dissociation of a metal/aminopolycarboxylate complex.},
doi = {10.1021/acs.inorgchem.6b02158},
journal = {Inorganic Chemistry},
number = 21,
volume = 55,
place = {United States},
year = {2016},
month = {10}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 5 works
Citation information provided by
Web of Science

Save / Share: