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Maiwald MM, Trumm M, Dardenne K, Rothe J, Skerencak-Frech A, Panak PJ. Speciation, thermodynamics and structure of Np(V) oxalate complexes in aqueous solution. Dalton Trans 2020; 49:13359-13371. [PMID: 32955047 DOI: 10.1039/d0dt02379e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The speciation, thermodynamics and structure of the Np(v) (as the NpO2+ cation) complexes with oxalate (Ox2-) are studied by different spectroscopic techniques. Near infrared absorption spectroscopy (Vis/NIR) is used to investigate complexation reactions as a function of the total ligand concentration ([Ox2-]total), ionic strength (Im = 0.5-4.0 mol kg-1 Na+(Cl-/ClO4-)) and temperature (T = 20-85 °C) for determination of the complex stoichiometry and thermodynamic functions (log β0n(T), ΔrH0n, ΔrS0n). Besides the solvated NpO2+ ion, two NpO2+ oxalate species (NpO2(Ox)n1-2n; n = 1, 2) are identified. With increasing temperature a decrease of the molar fractions of the 1 : 1 - and 1 : 2 - complexes is observed. Application of the law of mass action yields the temperature dependent conditional stability constants log β'n(T) at a given ionic strength which are extrapolated to IUPAC reference state conditions (Im = 0) according to the specific ion interaction theory (SIT). The log β0n(T) values of both complex species (log β01(25 °C) = 4.53 ± 0.12; log β02(25 °C) = 6.22 ± 0.24) decrease with increasing temperature confirming an exothermic complexation reaction. The temperature dependence of the thermodynamic stability constants is described by the integrated van't Hoff equation yielding the standard reaction enthalpies (ΔrH01 = -1.3 ± 0.7 kJ mol-1; ΔrH02 = -8.7 ± 1.4 kJ mol-1) and entropies (ΔrS01 = 82 ± 2 J mol-1 K-1; ΔrS02 = 90 ± 5 J mol-1 K-1) for the complexation reactions. In addition, the sum of the specific binary ion-ion interaction coefficients Δε0n(T) for the complexation reactions are obtained from SIT modelling as a function of the temperature. The structure of the complexes and the coordination mode of oxalate are investigated using EXAFS spectroscopy and quantum chemical calculations. The results show, that in case of both species NpO2(Ox)- and NpO2(Ox)23-, chelate complexes with 5-membered rings are formed.
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Affiliation(s)
- M M Maiwald
- Ruprecht Karls Universität Heidelberg, Physikalisch-Chemisches Institut, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany.
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Maiwald MM, Müller K, Heim K, Trumm M, Banik NL, Rothe J, Dardenne K, Skerencak-Frech A, Panak PJ. Determination of thermodynamic functions and structural parameters of NpO 2+ lactate complexes. NEW J CHEM 2020. [DOI: 10.1039/d0nj04291a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This work is a detailed spectroscopic and quantum chemical study on the complexation of Np(v) with the α-hydroxy carboxylate lactate giving information on the complex stoichiometries and thermodynamics (log β, ΔH, ΔS).
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Affiliation(s)
- M. M. Maiwald
- Ruprecht Karls Universität Heidelberg
- Physikalisch-Chemisches Institut
- Im Neuenheimer Feld 253
- D-69120 Heidelberg
- Germany
| | - K. Müller
- Helmholtz-Zentrum Dresden-Rossendorf
- Institut für Ressourcenökologie
- 01328 Dresden
- Germany
| | - K. Heim
- Helmholtz-Zentrum Dresden-Rossendorf
- Institut für Ressourcenökologie
- 01328 Dresden
- Germany
| | - M. Trumm
- Karlsruher Institut für Technologie (KIT)
- Institut für Nukleare Entsorgung (INE)
- D-76344 Eggenstein-Leopoldshafen
- Germany
| | - N. L. Banik
- Joint Research Center JRC - Karlsruhe
- G.II.6 - Nuclear Safeguards and Forensics
- European Commission
- D-76125 Karlsruhe
- Germany
| | - J. Rothe
- Karlsruher Institut für Technologie (KIT)
- Institut für Nukleare Entsorgung (INE)
- D-76344 Eggenstein-Leopoldshafen
- Germany
| | - K. Dardenne
- Karlsruher Institut für Technologie (KIT)
- Institut für Nukleare Entsorgung (INE)
- D-76344 Eggenstein-Leopoldshafen
- Germany
| | - A. Skerencak-Frech
- Karlsruher Institut für Technologie (KIT)
- Institut für Nukleare Entsorgung (INE)
- D-76344 Eggenstein-Leopoldshafen
- Germany
| | - P. J. Panak
- Ruprecht Karls Universität Heidelberg
- Physikalisch-Chemisches Institut
- Im Neuenheimer Feld 253
- D-69120 Heidelberg
- Germany
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Trumm M, Wagner C, Schimmelpfennig B, Geist A, Panak PJ. A closer look on the coordination of soft nitrogen-donor ligands to Cm(iii): SO3-Ph-BTBP. Dalton Trans 2016; 45:12308-11. [DOI: 10.1039/c6dt02052f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The combination of theory, VSBS and TRLFS revealed new insights into the coordination structure of [Cm(SO3-Ph-BTBP)2]5−.
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Affiliation(s)
- M. Trumm
- Institut für Nukleare Entsorgung (INE)
- Karlsruher Institut für Technologie
- D-76131 Karlsruhe
- Germany
| | - C. Wagner
- Institut für Nukleare Entsorgung (INE)
- Karlsruher Institut für Technologie
- D-76131 Karlsruhe
- Germany
- Ruprecht Karls Universität Heidelberg
| | - B. Schimmelpfennig
- Institut für Nukleare Entsorgung (INE)
- Karlsruher Institut für Technologie
- D-76131 Karlsruhe
- Germany
| | - A. Geist
- Institut für Nukleare Entsorgung (INE)
- Karlsruher Institut für Technologie
- D-76131 Karlsruhe
- Germany
| | - P. J. Panak
- Institut für Nukleare Entsorgung (INE)
- Karlsruher Institut für Technologie
- D-76131 Karlsruhe
- Germany
- Ruprecht Karls Universität Heidelberg
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Bauer N, Smith VC, MacGillivray RTA, Panak PJ. Complexation of Cm(iii) with the recombinant N-lobe of human serum transferrin studied by time-resolved laser fluorescence spectroscopy (TRLFS). Dalton Trans 2015; 44:1850-7. [DOI: 10.1039/c4dt03403a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The complexation of Cm(iii) with the recombinant N-lobe of human serum transferrin hTf/2N is investigated using TRLFS. The results reveal significant differences in the complexation properties of transferrin and the half molecule.
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Affiliation(s)
- N. Bauer
- Karlsruhe Institute of Technology (KIT)
- Campus North
- Institute for Nuclear Waste Disposal (INE)
- 76021 Karlsruhe
- Germany
| | - V. C. Smith
- University of British Columbia
- Department of Biochemistry and Molecular Biology and Centre for Blood Research
- Vancouver
- Canada
| | - R. T. A. MacGillivray
- University of British Columbia
- Department of Biochemistry and Molecular Biology and Centre for Blood Research
- Vancouver
- Canada
| | - P. J. Panak
- Karlsruhe Institute of Technology (KIT)
- Campus North
- Institute for Nuclear Waste Disposal (INE)
- 76021 Karlsruhe
- Germany
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Marquardt CM, Panak PJ, Apostolidis C, Morgenstern A, Walther C, Klenze R, Fanghänel T. Fluorescence spectroscopy on protactinium(IV) in aqueous solution. RADIOCHIM ACTA 2009. [DOI: 10.1524/ract.92.7.445.35755] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Summary
This work focuses on time-resolved laser fluorescence spectroscopy (TRLFS) of Pa(IV) in aqueous solution. Excitation at 308 nm causes a fluorescence emission with a peak maximum at about 460 nm. Thereby, the position of the band´s maximum depends on the concentration, the type of the acid, and the pH value. Increasing complexation of the Pa(IV) ion leads to an increasing hypsochromic shift of the emission band up to 46 nm. In contrast to the band position the half-width (61.6±1.4 nm) and the lifetime (16±2 ns) of the fluorescence emission do not change significantly with changes in the chemical environment of the Pa(IV). The results of this work show that speciation of Pa(IV) can be performed even in aqueous solution by using TRLFS.
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Kunze P, Seher H, Hauser W, Panak PJ, Geckeis H, Fanghänel T, Schäfer T. The influence of colloid formation in a granite groundwater bentonite porewater mixing zone on radionuclide speciation. J Contam Hydrol 2008; 102:263-272. [PMID: 18992961 DOI: 10.1016/j.jconhyd.2008.09.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Revised: 08/08/2008] [Accepted: 09/29/2008] [Indexed: 05/27/2023]
Abstract
In the context of deep geological storage of high level nuclear waste the repository will be designed as multiple barrier system including bentonite as buffer/backfill material and the host rock formation as geological barrier. The engineered barrier (bentonite) will be in contact with the host rock formation and consequently it can be expected that bentonite porewater will mix with formation groundwater. We simulate in this study the mixing of Grimsel groundwater (glacial melt water) with synthetic Febex porewater (assuming already saturated state) in a batch-type study and investigate the formation of colloids by laser-induced breakdown detection (LIBD) and SEM-EDX as well as the changes in radionuclide (U, Th, Eu) speciation via ultrafiltration or via time-resolved laser fluorescence spectroscopy (TRLFS) analysis in the case of Cm(III). Based on PHREEQC saturation index (SI) calculations a precipitation of calcite might be expected at low Febex porewater (FPW) content (<20%), fluorite precipitation at FPW contents <60% and gibbsite precipitation at FPW contents above 10%. The colloids generated in the mixing zone aggregate when the synthetic FPW content exceeds 10%. LIBD analysis of the time-dependent colloid generation/aggregation revealed a low concentration of colloids to be stable with an estimated plateau value around 100-200 ppt and an average colloid diameter around 30 nm after 140 days reaction time at FPW admixture >10%. SEM/EDX mostly identifies Al/Si containing colloidal phases and some sulfates could be found under certain admixture ratios. TRLFS studies show that the Cm speciation is strongly influenced by colloid formation in all solutions. In the Febex pore water/GGW mixing zone with high groundwater contents (>80%) colloids are newly formed and Cm is almost quantitatively associated with most likely polysilicilic acid colloids.
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Affiliation(s)
- P Kunze
- University of Applied Science (FH), Faculty of Mechanical Engineering, P.O. Box 1455, D-02754 Zittau/Görlitz, Germany
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Stumpf S, Billard I, Gaillard C, Panak PJ, Dardenne K. Time-Resolved Laser Fluorescence Spectroscopy and Extended X-Ray Absorption Spectroscopy Investigations of the N3− Complexation of Eu(III), Cm(III), and Am(III) in an Ionic Liquid: Differences and Similarities. Inorg Chem 2008; 47:4618-26. [DOI: 10.1021/ic7023567] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S. Stumpf
- European Commission, JRC, Institute for Transuranium Elements, Karlsruhe, 76125, Germany, IPHC/DRS, Chimie Nucléaire, BP. 28, 67037 Strasbourg, France, and Forschungszentrum Karlsruhe, Institut für Nukleare Entsorgung, P.O. Box 3640, 76021 Karlsruhe, Germany
| | - I. Billard
- European Commission, JRC, Institute for Transuranium Elements, Karlsruhe, 76125, Germany, IPHC/DRS, Chimie Nucléaire, BP. 28, 67037 Strasbourg, France, and Forschungszentrum Karlsruhe, Institut für Nukleare Entsorgung, P.O. Box 3640, 76021 Karlsruhe, Germany
| | - C. Gaillard
- European Commission, JRC, Institute for Transuranium Elements, Karlsruhe, 76125, Germany, IPHC/DRS, Chimie Nucléaire, BP. 28, 67037 Strasbourg, France, and Forschungszentrum Karlsruhe, Institut für Nukleare Entsorgung, P.O. Box 3640, 76021 Karlsruhe, Germany
| | - P. J. Panak
- European Commission, JRC, Institute for Transuranium Elements, Karlsruhe, 76125, Germany, IPHC/DRS, Chimie Nucléaire, BP. 28, 67037 Strasbourg, France, and Forschungszentrum Karlsruhe, Institut für Nukleare Entsorgung, P.O. Box 3640, 76021 Karlsruhe, Germany
| | - K. Dardenne
- European Commission, JRC, Institute for Transuranium Elements, Karlsruhe, 76125, Germany, IPHC/DRS, Chimie Nucléaire, BP. 28, 67037 Strasbourg, France, and Forschungszentrum Karlsruhe, Institut für Nukleare Entsorgung, P.O. Box 3640, 76021 Karlsruhe, Germany
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