Electronic structure and bonding of lanthanoid(iii) carbonates

Jeanvoine, Yannick; Miró, Pere; Martelli, Fausto; Cramer, Christopher J.; Spezia, Riccardo

doi:10.1039/c2cp41996c

Cited by 41 publications

(41 citation statements)

References 67 publications

(80 reference statements)

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“…The results yielded an average Y-O distance of 2.37 ± 0.02 Å for the Y-sol sample and 2.38 ± 0.01 Å for YSO4-sol ( Table 1). The intense peak in the FT function at 2.38 Å for the two aqueous references represents the first solvation shell, and its asymmetry reveals a distribution of Y-O interatomic distances, as reported previously by Lindqvist et al 24 The coordination numbers (CN) were 7.6 ± 1.9 and 7.9 ± 0.9 for Y-sol and YSO4-sol, respectively, which are close to the expected value of 8 for 23,24,28 Likewise aqueous REE carbonate and phosphate complexes, [31][32][33] aqueous Y-SO4 ion-pairs form inner-sphere complexes. This result contrasts with other ligands such as chloride, which hardly forms inner sphere complexes at similar concentrations to those used in this study.…”

Section: Analytical Techniquessupporting

confidence: 84%

Solid and Aqueous Speciation of Yttrium in Passive Remediation Systems of Acid Mine Drainage

Lozano

Fernández-Martı́nez

Ayora

et al. 2019

Environ. Sci. Technol.

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Yttrium belongs to the rare earth elements (REE) together with lanthanides and scandium. REE are commonly used in modern technologies, and their limited supply has made it necessary to look for new alternative resources. Acid mine drainage (AMD) is a potential resource since is moderately enriched in REE. In fact, in passive remediation systems, which are implemented to minimize the environmental impacts of AMD, REE are mainly retained in basaluminite, an aluminum hydroxysulfate precipitate. In this study, the solid and liquid speciation and the local structure of yttrium were studied in high sulfate aqueous solutions, basaluminite standards and samples from remediation columns using synchrotron-based techniques and molecular modeling. Pair distribution function (PDF) analyses and ab initio molecular dynamics density functional theory models of the yttrium sulfate solution show that the YSO 4 + ion pair forms a monodentate inner sphere complex. Extended X-ray absorption fine structure (EXAFS) and PDF analyses show that Y is retained by basaluminite forming a monodentate inner-sphere surface complex at the aluminum hydroxide surface. EXAFS of the column samples show that its signal is represented in more than 75% by the signal of a basaluminite which YSO 4 + is forming an inner-sphere complex. The atomic vision of the REE configuration in AMD environments could help for a deeper research of the REE recovery from waste generated in the AMD remediation systems.

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Section: Analytical Techniquessupporting

confidence: 84%

Solid and Aqueous Speciation of Yttrium in Passive Remediation Systems of Acid Mine Drainage

Lozano

Fernández-Martı́nez

Ayora

et al. 2019

Environ. Sci. Technol.

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“…These findings for the lutetium halides are in line with similar findings for various lanthanide oxo‐compounds (carbonates, phosphates, borates, etc.) Closed shell freezing is more serious than the effective‐core pseudopotential approach, which can simulate the shell relaxation.…”

Section: Discussionmentioning

confidence: 99%

Ionic bonding of lanthanides, as influenced by d- and f-atomic orbitals, by core-shells and by relativity

Schwarz

et al. 2015

J. Comput. Chem.

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Lanthanide trihalide molecules LnX3 (X = F, Cl, Br, I) were quantum chemically investigated, in particular detail for Ln = Lu (lutetium). We applied density functional theory (DFT) at the nonrelativistic and scalar and SO-coupled relativistic levels, and also the ab initio coupled cluster approach. The chemically active electron shells of the lanthanide atoms comprise the 5d and 6s (and 6p) valence atomic orbitals (AO) and also the filled inner 4f semivalence and outer 5p semicore shells. Four different frozen-core approximations for Lu were compared: the (1s(2) -4d(10) ) [Pd] medium core, the [Pd+5s(2) 5p(6) = Xe] and [Pd+4f(14) ] large cores, and the [Pd+4f(14) +5s(2) 5p(6) ] very large core. The errors of LuX bonding are more serious on freezing the 5p(6) shell than the 4f(14) shell, more serious upon core-freezing than on the effective-core-potential approximation. The LnX distances correlate linearly with the AO radii of the ionic outer shells, Ln(3+) -5p(6) and X(-) -np(6) , characteristic for dominantly ionic Ln(3+) -X(-) binding. The heavier halogen atoms also bind covalently with the Ln-5d shell. Scalar relativistic effects contract and destabilize the LuX bonds, spin orbit coupling hardly affects the geometries but the bond energies, owing to SO effects in the free atoms. The relativistic changes of bond energy BE, bond length Re , bond force k, and bond stretching frequency vs do not follow the simple rules of Badger and Gordy (Re ∼BE∼k∼vs ). The so-called degeneracy-driven covalence, meaning strong mixing of accidentally near-degenerate, nearly nonoverlapping AOs without BE contribution is critically discussed.

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“…15 Another recent theoretical contribution in this area was a report by Sinha et al on [Nd(CO 3 ) 4 ] 5À using the Parameterized Model 3 (PM3) semi-empirical method. 16 Notwithstanding these two studies, the first quantitative and systematic theoretical study undertaken to characterize the structures and bonding of lanthanoid(III) tri-and tetra-carbonates was reported recently by Jeanvoine et al 17 They studied different clusters by means of Density Functional Theory (DFT) pointing out that: (1) in the gas phase the most stable structure is the full bi-dentate for tri-carbonate complexes, while for the tetra-carbonate complexes it is the full mono-dentate; (2) in water, modeled there as a continuum -i.e. no explicit water molecules were considered -in both cases the full bi-dentate complexes are the most stable structures; (3) the tri-carbonate structure is more stable than the tetra-carbonate one; (4) the Ln(III)-carbonate interaction is mainly ionic, thus allowing use of a simple, physics based, interaction potential to study such complexes in liquid water by means of classical molecular dynamics simulations.…”

Section: Introductionmentioning

confidence: 99%

Hydration properties of lanthanoid(iii) carbonate complexes in liquid water determined by polarizable molecular dynamics simulations

Martelli

Jeanvoine

Vercouter

et al. 2014

Phys. Chem. Chem. Phys.

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In this work we have studied the structure and dynamics of complexes formed by three and four carbonates and a central lanthanoid(III) ion in liquid water by means of polarizable molecular dynamics simulations. With this aim we have developed a force field employing an extrapolation procedure that was previously developed for lanthanoid(III) aqua ions and then we have validated it against DFT-based data. In this way we were able to shed light on properties of the whole series, finding some similarities and differences across the series, and to help in interpreting experiments on those systems. We found that the bi-dentate tri-carbonate complexes are the most stable for all the atoms, but a variation of the number of water molecules in the first ion shell, and the associated exchange dynamics, is observed from lighter to heavier elements. On the other hand, for four-carbonate systems only one water molecule is observed in the first shell, with 10-20% probability, for La(III) and Ce(III), while for the rest of the series it seems impossible for a water molecule to enter the first ion shell in the presence of such an excess of carbonate ligands. Finally, the good performance of our extrapolation procedure, based on ionic radii, makes us confident in extending such approaches to study the structure and dynamics of other systems in solution containing Ln(III) and An(III) ions. This parametrization method results particularly useful since it does not need expensive quantum chemistry calculations for all the atoms in the series.

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Electronic structure and bonding of lanthanoid(iii) carbonates

Cited by 41 publications

References 67 publications

Solid and Aqueous Speciation of Yttrium in Passive Remediation Systems of Acid Mine Drainage

Solid and Aqueous Speciation of Yttrium in Passive Remediation Systems of Acid Mine Drainage

Ionic bonding of lanthanides, as influenced by d- and f-atomic orbitals, by core-shells and by relativity

Hydration properties of lanthanoid(iii) carbonate complexes in liquid water determined by polarizable molecular dynamics simulations

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