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

Title: Neodymium(III) Complexation by Amino-Carbohydrates via a Ligand-Controlled Hydrolysis Mechanism

Abstract

Chelation of neodymium-III Nd(III) by D-glucosamine (DGA) and chitosan was investigated in solution at near-physiological pH and ionic strength. This research demonstrates the first example of the lanthanide ion heteroleptic hydroxo-carbohydrate complex in solution. It was demonstrated that DGA and chitosan suppressed formation of polynuclear Nd(III) species at elevated pH.

Authors:
; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1024077
Report Number(s):
PNNL-SA-79040
TRN: US201119%%74
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Chemical Communications, 47(28):8160-8162; Journal Volume: 47; Journal Issue: 28
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; HYDROLYSIS; RARE EARTHS; NEODYMIUM; CARBOHYDRATES; LIGANDS; GLUCOSAMINE; LANTHANIDE-HYDROXO COMPLEXES; HYPERSENSITIVE TRANSITIONS; OSCILLATOR-STRENGTH; CHITOSAN CHEMISTRY; HEAVY-METALS; IONS; COORDINATION; EQUILIBRIA; STABILITY; SORBENTS

Citation Formats

Levitskaia, Tatiana G., Chen, Yongsheng, Fulton, John L., and Sinkov, Sergey I.. Neodymium(III) Complexation by Amino-Carbohydrates via a Ligand-Controlled Hydrolysis Mechanism. United States: N. p., 2011. Web. doi:10.1039/C1CC11871D.
Levitskaia, Tatiana G., Chen, Yongsheng, Fulton, John L., & Sinkov, Sergey I.. Neodymium(III) Complexation by Amino-Carbohydrates via a Ligand-Controlled Hydrolysis Mechanism. United States. doi:10.1039/C1CC11871D.
Levitskaia, Tatiana G., Chen, Yongsheng, Fulton, John L., and Sinkov, Sergey I.. Thu . "Neodymium(III) Complexation by Amino-Carbohydrates via a Ligand-Controlled Hydrolysis Mechanism". United States. doi:10.1039/C1CC11871D.
@article{osti_1024077,
title = {Neodymium(III) Complexation by Amino-Carbohydrates via a Ligand-Controlled Hydrolysis Mechanism},
author = {Levitskaia, Tatiana G. and Chen, Yongsheng and Fulton, John L. and Sinkov, Sergey I.},
abstractNote = {Chelation of neodymium-III Nd(III) by D-glucosamine (DGA) and chitosan was investigated in solution at near-physiological pH and ionic strength. This research demonstrates the first example of the lanthanide ion heteroleptic hydroxo-carbohydrate complex in solution. It was demonstrated that DGA and chitosan suppressed formation of polynuclear Nd(III) species at elevated pH.},
doi = {10.1039/C1CC11871D},
journal = {Chemical Communications, 47(28):8160-8162},
number = 28,
volume = 47,
place = {United States},
year = {Thu Jul 28 00:00:00 EDT 2011},
month = {Thu Jul 28 00:00:00 EDT 2011}
}
  • The compounds (Me[sub 2]N)CH(PO[sup 3]H[sub 2])[sub 2](MAMDP) and MeC(NH[sub 2])(PO[sub 3]H[sub 2])[sub 2](AEDP) have been synthesized. These compounds have been titrated with base and the protonation constants determined. Titration data of pH against added acid or base show that AEDP acts as a ligand toward In[sup 3+] and that MAMDP binds as a ligand to In[sup 3+], Ga[sup 3+], Fe[sup 3+], Gd[sub 3+], and Nd[sub 3+]. From a least-squares fit of the pH titration curves, the stability and protonation constants have been obtained for solutions containing these ligands and these trivalent metal ions. The ligands bind to the trivalent metalmore » ions via the phosphonate oxygens, although it is likely that hydrogen bonding occurs between water and the phosphonate ligand. For the ions In[sup 3+], Ga[sup 3+], and Fe[sup 3+], the logarithms of the stability constants log K[sub 101] and log K[sub 102] (where K[sub 101] = [ML[sup [minus]]]/[M[sup 3+]][L[sup 4[minus]]] and K[sub 102] = [MO[sub 2][sup 5[minus]]]/[M[sup 3+]][L[sup 4[minus]]][sup 2]) have the respective values of 30.0, 25.8, 28.8 and 35.8, 33.7, 34.3. For the lanthanide ions Nd[sup 3+] and Gd[sup 3+] the values are lower at 16.0, 17.6 and 20.4, 20.7, respectively. This pattern of stability constants follows the trend for the complexation of EDTA with these trivalent metal ions. The compound MAMDP remains coordinated to the metal ions in solutions of low acidity because protonation occurs at the free rather than the complexed phosphonate oxygens. 20 refs., 7 figs., 2 tabs.« less
  • The protonation of lactate has been studied in a variety of electrolyte solutions using microcalorimetry to reveal a distinct medium influence imposed on the thermochemistry of the investigated equilibrium. The thermochemistry of lactate protonation, when studied directly in 1.0 M sodium lactate, agreed well with the studies performed in trifluoromethanesulfonate (triflate). This thermodynamic agreement suggests that the physical chemistry of lactate in the solutions applicable to the TALSPEAK process – a solvent extraction method for separating trivalent actinides from trivalent lanthanides within the scope of used nuclear fuel processing efforts – may be simulated in triflate solutions. Potentiometry, spectrophotometry andmore » microcalorimetry have been subsequently used to study the thermodynamic features of neodymium and americium complexation by lactate using triflate as a strong background electrolyte. Three successive mononuclear lactate complexes were identified for Nd(III) and Am(III). The stability constants for neodymium, log ß1 = 2.60 ± 0.01, log ß2 = 4.66 ± 0.02 and log ß3 = 5.6 ± 0.1, and for americium, log ß1 = 2.60 ± 0.06, log ß2 = 4.7 ± 0.1 and log ß3 = 6.2 ± 0.2, were found to closely agree with the thermodynamic studies reported in sodium perchlorate solutions. Consequently, the thermodynamic medium effect, imposed on the TALSPEAK-related solution equilibria by the presence of strong background electrolytes such as NaClO4 and NaNO3, do not significantly impact the speciation in solution.« less
  • The enthalpies of formation of the 1:1 complexes of Am(III) with acetate an a series of amino carboxylate ligands were determined by titration calorimetry. The estimated {Delta}H{sub 101} values are -6.8, 4.5, 12.6, 23.9, 10.8, 39.5, and -13.3 kJ mol{sup {minus}1} for complexation by acetate, IDA, NTA, EDTA, DCTA, DTPA, and TMDTA, respectively. Comparison of these values with those for the Eu(III) and Cm(III) complexation provides no evidence of significant differences in the bonding of these three metal ions with the ligands studied. 13 refs., 3 figs., 3 tabs.
  • To gain insight on the role of mixed solvents on the thermodynamic driving forces for the complexation between trivalent f-elements and organic ligands, solution phase thermodynamic parameters were determined for Eu(III) complexation with 2-hydroxyisobutyric acid (HIBA) and 2-aminoisobutyric acid (AIBA) in mixed methanol (MeOH)-water and N,N-dimethylformamide (DMF)-water solvents. Included in this study were the determination of mixed solvent autoprotolysis constants (pK α) as well as the thermodynamic formation constants: log β, ΔG, ΔH, and ΔS, for ligand protonation and Eu(III)-ligand complexation utilizing potentiometry and calorimetry techniques. The results presented are conditional thermodynamic values determined at an ionic strength of 1.0more » M NaClO 4 and a temperature of 298 K. It was found that moving from an aqueous solution to a binary aqueous-organic solvent affected all solution equilibria to some degree and that the extent of change depended on both the type of mixed solvent and the ligand in each study. Here, the ability to understand and predict these changes in thermodynamic values as a function of solvent composition provides important information about the chemistry of the trivalent f-elements.« less
  • Tris(acetylacetonato)technetium(III), /sup 99/Tc(acac)/sup 3/ undergoes ligand exchange in acetylacetone (Hacac) at 125-141/degrees/C. The rate observed by the /sup 14/C-labeling method is expressed by rate = k/sub 1/(complex) at (complex) = 0.003-0.007 M, (Hacac) = 9.7 M, and (H/sub 2/O) = 0.04-0.1 M; k/sub 1/ = 2.1 /plus minus/ 0.1 x 10/sup -4/ s/sup -1/ at 141/degrees/C. No water catalysis was observed. ..delta..H/double dagger/ and ..delta..S/double dagger/ are 119 /plus minus/ 7 kJ mol/sup -1/ and -27 /plus minus/ 18 J K/sup -1/ mol/sup -1/, respectively. The dilution with acetonitrile reduced the rate linearly with (Hacac). The deuterium isotope effect k/submore » 1/(H)/k/sub -1/ (D) was modest (2.3 /plus minus/ 0.3). The I/sub a/ mechanism is assigned to the rate-determining formation of the intermediate containing a one-ended acac/sup -/ and a unidentate Hacac. The lability and the mechanism are regarded as reflecting straightforwardly the kinetic nature of Tc/sup III/ on the basis of the previously reported linear free energy relationship between the present exchange system and the ligand-substitution processes of aqua complexes for various tervalent metal ions. The lability of Tc/sup III/ with the low-spin d/sup 4/ configuration was found to be very close to that of Cr/sup III/, much lower than that of Mo/sup III/, and slightly higher than that of Ru/sup III/ and Rh/sup III/; Mo/sup III/>> Tc/sup III/ > Ru/sup III/ > Rh/sup III/. The mechanism is consistent with that previously proposed for M/sup III/(acac)/sub 3/ complexes, on the basis of an estimated ionic radius of Tc/sup III/. 24 references, 2 figures, 2 tables.« less