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Buchanan CA, Ko E, Cira S, Balasubramanian M, Goldsmith BR, Singh N. Structures and Free Energies of Cerium Ions in Acidic Electrolytes. Inorg Chem 2020; 59:12552-12563. [PMID: 32845625 DOI: 10.1021/acs.inorgchem.0c01645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Ce3+/Ce4+ redox potential changes with the electrolyte, which could be due to unequal anion complexation free energies between Ce3+ and Ce4+ or a change in the solvent electrostatic screening. Ce complexation with anions and solvent screening also affect the solubility of Ce and charge transfer kinetics for electrochemical reactions involving waste remediation and energy storage. We report the structures and free energies of cerium complexes in seven acidic electrolytes based on Extended X-ray Absorption Fine Structure, UV-vis, and Density Functional Theory calculations. Ce3+ coordinates with nine water molecules as [Ce(H2O)9]3+ in all studied electrolytes. However, Ce4+ complexes with anions in all electrolytes except HClO4. Thus, our results suggest that Ce4+-anion complexation leads to the large shifts in standard redox potential. Long range screening effects are smaller than the anion complexation energies but could be responsible for changes in the Ce solubility with acid.
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Affiliation(s)
- Cailin A Buchanan
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.,Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Eunbyeol Ko
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.,Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Spencer Cira
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Mahalingam Balasubramanian
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Bryan R Goldsmith
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.,Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Nirala Singh
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.,Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
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Acher E, Masella M, Vallet V, Réal F. Properties of the tetravalent actinide series in aqueous phase from a microscopic simulation self-consistent engine. Phys Chem Chem Phys 2020; 22:2343-2350. [PMID: 31932817 DOI: 10.1039/c9cp04912f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the context of nuclear fuel recycling and environmental issues, the understanding of the properties of radio-elements with various approaches remains a challenge regarding their dangerousness. Moreover, experimentally, some issues are also of importance; first, it is imperative to work at sufficiently high concentrations to reach the sensitivities of the analytical tools, however this condition often leads to precipitation for some of them; second, stabilizing specific oxidation states of some actinides remains a challenge, thus making it difficult to extract general trends across the actinide series. Complementary to experiments, modeling can be used to unbiasedly probe the actinide's properties in an aquatic environment and offers a predictive tool. We report the first molecular dynamics simulations based on homogeneously built force fields for the whole series of the tetravalent actinides in aqueous phase from ThIV to BkIV and including PuIV. The force fields used to model the interactions among the constituents include polarization and charge donation microscopic effects. They are built from a self-consistent iterative ab initio based engine that can be included in future developments as an element of a potential machine learning procedure devoted to generating accurate force fields. The comparison of our simulated hydrated actinide properties to available experimental data shows the model robustness and the relevance of our parameter assignment engine. Moreover, our simulated structural, dynamical and evolution of the hydration free energy data show that, apart from AmIV and CmIV, the actinide properties change progressively along the series.
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Marsac R, Réal F, Banik NL, Pédrot M, Pourret O, Vallet V. Aqueous chemistry of Ce(iv): estimations using actinide analogues. Dalton Trans 2018; 46:13553-13561. [PMID: 28952626 DOI: 10.1039/c7dt02251d] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The prediction of cerium (Ce) aqueous speciation is relevant in many research fields. Indeed, Ce compounds are used for many industrial applications, which may require the control of Ce aqueous chemistry for their synthesis. The aquatic geochemistry of Ce is also of interest. Due to its growing industrial use and its release into the environment, Ce is now considered as an emerging contaminant. Cerium is also used as a proxy of (paleo)redox conditions due to the Ce(iv)/Ce(iii) redox transition. Finally, Ce(iv) is often presented as a relevant analogue of tetravalent actinides (An(iv)). In the present study, quantum chemical calculations were conducted to highlight the similarities between the structures of Ce(iv) and tetravalent actinide (An(iv); An = Th, Pa, U, Np, Pu) aqua-ions, especially Pu(iv). The current knowledge of An(iv) hydrolysis, solubility and colloid formation in water was briefly reviewed but important discrepancies were observed in the available data for Ce(iv). Therefore, new estimations of the hydrolysis constants of Ce(iv) and the solubility of Ce(iv)-(hydr)oxides are proposed, by analogy with Pu(iv). By plotting pH-Eh (Pourbaix) diagrams, we showed that the pH values corresponding to the onset of Ce(iv) species formation (i.e. Ce(iv)-(hydr)oxide or dissolved Ce(iv)) agreed with various experimental results. Although further experimental studies are required to obtain a more accurate thermodynamic database, the present work might yet help to predict more accurately the Ce chemical behavior in aqueous solution.
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Affiliation(s)
- Rémi Marsac
- Géosciences Rennes UMR 6118, Université Rennes 1, CNRS, 35042, Rennes Cedex, France.
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Shen S, Chi X, Dong J, Huo S, Tian H, Xu L, Shi T. Oxidation of the drug tiopronin by Cerium(IV) in perchloric acid media: Kinetic and mechanistic analyses. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.09.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Li P, Song LF, Merz KM. Parameterization of highly charged metal ions using the 12-6-4 LJ-type nonbonded model in explicit water. J Phys Chem B 2014; 119:883-95. [PMID: 25145273 PMCID: PMC4306492 DOI: 10.1021/jp505875v] [Citation(s) in RCA: 210] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
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Highly charged metal ions act as
catalytic centers and structural
elements in a broad range of chemical complexes. The nonbonded model
for metal ions is extensively used in molecular simulations due to
its simple form, computational speed, and transferability. We have
proposed and parametrized a 12-6-4 LJ (Lennard-Jones)-type nonbonded
model for divalent metal ions in previous work, which showed a marked
improvement over the 12-6 LJ nonbonded model. In the present study,
by treating the experimental hydration free energies and ion–oxygen
distances of the first solvation shell as targets for our parametrization,
we evaluated 12-6 LJ parameters for 18 M(III) and 6 M(IV) metal ions
for three widely used water models (TIP3P, SPC/E, and TIP4PEW). As expected, the interaction energy underestimation of the 12-6
LJ nonbonded model increases dramatically for the highly charged metal
ions. We then parametrized the 12-6-4 LJ-type nonbonded model for
these metal ions with the three water models. The final parameters
reproduced the target values with good accuracy, which is consistent
with our previous experience using this potential. Finally, tests
were performed on a protein system, and the obtained results validate
the transferability of these nonbonded model parameters.
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Affiliation(s)
- Pengfei Li
- Department of Chemistry, Department of Biochemistry and Molecular Biology, Michigan State University , 578 S. Shaw Lane, East Lansing, Michigan 48824-1322, United States
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Lutz OMD, Hofer TS, Randolf BR, Weiss AKH, Rode BM. A QMCF-MD investigation of the structure and dynamics of Ce4+ in aqueous solution. Inorg Chem 2012; 51:6746-52. [PMID: 22651096 DOI: 10.1021/ic300385s] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A quantum-mechanical charge-field molecular dynamics simulation has been performed for a tetravalent Ce ion in aqueous solution. In this framework, the complete first and second hydration spheres are treated by ab initio quantum mechanics supplemented by an electrostatic embedding technique, making the construction of non-Coulombic solute-solvent potentials unnecessary. During the 10 ps of simulation time, the structural aspects of the solution were analyzed by various methods. Experimental results such as the mean Ce-O bond distance and the predicted first-shell coordination number were compared to the results obtained from the simulation resolving some ambiguities in the literature. The dynamics of the system were characterized by mean ligand residence times and frequency/force constant calculations. Furthermore, Ce-O and Ce-H angular radial distribution plots were employed, yielding deeper insight into the structural and dynamical aspects of the system.
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Affiliation(s)
- Oliver M D Lutz
- Theoretical Chemistry Division, Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria
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Lutz OMD, Hofer TS, Randolf BR, Rode BM. Hydration of trivalent lanthanum revisited - An ab initio QMCF-MD approach. Chem Phys Lett 2012; 536:50-54. [PMID: 23564962 PMCID: PMC3617652 DOI: 10.1016/j.cplett.2012.03.065] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 03/19/2012] [Indexed: 11/30/2022]
Abstract
The previously investigated La3+-hydrate has been re-evaluated by means of the quantum mechanical charge field (QMCF) molecular dynamics (MD) approach. Improved description of the hydration characteristics has been realised by including the full second hydration shell into the quantum mechanically treated region and by introducing the influence of the surrounding bulk via an electrostatic embedding technique. Analytical tools such as the ligand angular radial distribution analysis have been employed to gain deeper insight into the structural features of the hydrate. La3+ simultaneously forms nona- and decahydrates with capped trigonal and quadratic prismatic structure, besides small amounts of an octahydrate.
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Affiliation(s)
- Oliver M D Lutz
- Theoretical Chemistry Division, Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
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David FH, Vokhmin V. Hydration and Entropy Model for Ionic and Covalent Monatomic Ions. J Phys Chem A 2001. [DOI: 10.1021/jp0104278] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- François H. David
- Institut de Physique Nucléaire, 91406 Orsay, France, and Institute of Physical Chemistry, RAS, 117915 Moscow, Russia
| | - Valery Vokhmin
- Institut de Physique Nucléaire, 91406 Orsay, France, and Institute of Physical Chemistry, RAS, 117915 Moscow, Russia
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Solera JA, García J, Proietti MG. Multielectron excitations at the L edges in rare-earth ionic aqueous solutions. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:2678-2686. [PMID: 9979038 DOI: 10.1103/physrevb.51.2678] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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