Binary and ternary complexation of NpO 2 + with carboxylate and aminocarboxylate ligands
Abstract The complex formation of NpO 2 + with carboxylates: oxalic acid (Ox), malonic acid (Mal) succinic acid (Suc); glutaric acid (Glu), methylmalonic acid (Memal), oxydiacetic acid (ODA), TDA (thiodiacetic acid) and citric acid (Cit) and aminocarboxylates: iminodiacetic acid (IDA), methyliminodi...
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Published in | Radiochimica acta Vol. 102; no. 9; pp. 781 - 796 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
28.09.2014
|
Online Access | Get full text |
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Summary: | Abstract
The complex formation of NpO
2
+
with carboxylates: oxalic
acid (Ox), malonic acid (Mal) succinic acid (Suc); glutaric acid
(Glu), methylmalonic acid (Memal), oxydiacetic acid (ODA), TDA
(thiodiacetic acid) and citric acid (Cit) and aminocarboxylates:
iminodiacetic acid (IDA), methyliminodiacetic acid
(MIDA),nitrilotriacetic acid (NTA), 2-hydroxyethylethylenediamine
triacetic acid (HEDTA),ethylenediaminetetraacetic acid (EDTA) and
diethylenetriaminepentaacetic acid (DTPA) was studied by solvent
extraction in 6.60 m NaClO
4
at
25 ℃. The formation of only the 1:1
NpO
2
+
complex was observed with the ligands under
investigation. The complexation of NpO
2
+
with Ox, IDA,
ODA and TDA was also measured at variable temperatures ranging from
25–60 ℃ in 6.60 m
NaClO
4
. Results show that the complexation of
NpO
2
+
with these ligands increases with increasing
temperature. The enthalpy and entropy of complexation of
NpO
2
+
were calculated from the temperature dependence of
the stability constants using the Van't Hoff equation. Additionally,
the formation of an aqueous ternary complex of the form
NpO
2
(X)(L) (X = EDTA or HEDTA; L = Ox
or ODA) was identified for NpO
2
+
at
25 ℃. Stabilities of these complexes are measured
and discussed in term of their structures and basicities. |
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ISSN: | 0033-8230 2193-3405 |
DOI: | 10.1515/ract-2013-2205 |