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Riefer A, Hackert-Oschätzchen M, Plänitz P, Meichsner G. Characterization of iron(III) in aqueous and alkaline environments with ab initio and ReaxFF potentials. J Chem Phys 2024; 160:082501. [PMID: 38411229 DOI: 10.1063/5.0182460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 02/05/2024] [Indexed: 02/28/2024] Open
Abstract
The iron(III) complexes [Fe(H2O)n(OH)m]3-m (n + m = 5, 6, m ≤ 3) and corresponding proton transfer reactions are studied with total energy calculations, the nudged elastic band (NEB) method, and molecular dynamics (MD) simulations using ab initio and a modification of reactive force field potentials, the ReaxFF-AQ potentials, based on the implementation according to Böhm et al. [J. Phys. Chem. C 120, 10849-10856 (2016)]. Applying ab initio potentials, the energies for the reactions [Fe(H2O)n(OH)m]3-m + H2O → [Fe(H2O)n-1(OH)m+1]2-m + H3O+ in a gaseous environment are in good agreement with comparable theoretical results. In an aqueous (aq) or alkaline environment, with the aid of NEB computations, respective minimum energy paths with energy barriers of up to 14.6 kcal/mol and a collective transfer of protons are modeled. Within MD simulations at room temperature, a permanent transfer of protons around the iron(III) ion is observed. The information gained concerning the geometrical and energetic properties of water and the [Fe(H2O)n(OH)m]3-m complexes from the ab initio computations has been used as reference data to optimize parameters for the O-H-Fe interaction within the ReaxFF-AQ approach. For the optimized ReaxFF-AQ parameter set, the statistical properties of the basic water model, such as the radial distribution functions and the proton hopping functions, are evaluated. For the [Fe(H2O)n(OH)m]3-m complexes, it was found that while geometrical and energetic properties are in good agreement with the ab initio data for gaseous environment, the statistical properties as obtained from the MD simulations are only partly in accordance with the ab initio results for the iron(III) complexes in aqueous or alkaline environments.
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Affiliation(s)
- Arthur Riefer
- Chair of Manufacturing Technology with Focus Machining, Institute of Manufacturing Technology and Quality Management (IFQ), Faculty of Mechanical Engineering, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany
| | - Matthias Hackert-Oschätzchen
- Chair of Manufacturing Technology with Focus Machining, Institute of Manufacturing Technology and Quality Management (IFQ), Faculty of Mechanical Engineering, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany
| | - Philipp Plänitz
- AQcomputare Gesellschaft für Materialberechnung mbH, 09125 Chemnitz, Germany
| | - Gunnar Meichsner
- Chair of Manufacturing Technology with Focus Machining, Institute of Manufacturing Technology and Quality Management (IFQ), Faculty of Mechanical Engineering, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany
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2
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Boukar O, Fifen JJ, Conradie J, Conradie MM. Solvation energies of the ferrous ion in water and in ammonia at various temperatures. J Mol Model 2024; 30:52. [PMID: 38285315 DOI: 10.1007/s00894-024-05839-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/09/2024] [Indexed: 01/30/2024]
Abstract
CONTEXT The solvation of metal ions is crucial to understanding relevant properties in physics, chemistry, or biology. Therefore, we present solvation enthalpies and solvation free energies of the ferrous ion in water and ammonia. Our results agree well with the experimental reports for the hydration free energy and hydration enthalpy. We obtained [Formula: see text] kJ mol[Formula: see text] for the hydration free energy and [Formula: see text] kJ mol[Formula: see text] for the hydration enthalpy of ferrous ion in water at room temperature. At ambient temperature, we obtained [Formula: see text] kJ mol[Formula: see text] as the [Formula: see text] ammoniation free energy and [Formula: see text] kJ mol[Formula: see text] for the ammoniation enthalpy. In addition, the free energy of solvation is deeply affected when the temperature increases. This pattern can be attributed to the rise of entropy when the temperature rises. Besides, the temperature does not affect the ammoniation enthalpies and the hydration enthalpy of the [Formula: see text] ion. METHOD All the geometry optimizations are performed at the MP2 methods associated with the 6-31++g(d,p) basis set of Pople. solvated phase structures of [Formula: see text] ion in water or in ammonia are performed using the PCM model. The [Formula: see text] program suite was used to perform all the calculations. The program TEMPO was also used to evaluate the temperature sensitivity of the different obtained geometries.
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Affiliation(s)
- Ousman Boukar
- Department of Physics, Faculty of Science, University of Maroua, P.O. Box 46, Maroua, Cameroon.
| | - Jean Jules Fifen
- Quantum Theory and Aplications Unit, Department of Physics, Faculty of Science, The University of Ngaoundere, P.O. Box 454, Ngaoundere, Cameroon.
| | - Jeanet Conradie
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
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3
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Formentini TA, Cornelis G, Gustafsson JP, Leicht K, Tiberg C, Planer-Friedrich B, Durant N, Fan D, Kleja DB. Immobilizing arsenic in contaminated anoxic aquifer sediment using sulfidated and uncoated zero-valent iron (ZVI). JOURNAL OF HAZARDOUS MATERIALS 2024; 462:132743. [PMID: 37837779 DOI: 10.1016/j.jhazmat.2023.132743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/31/2023] [Accepted: 10/07/2023] [Indexed: 10/16/2023]
Abstract
Arsenic (As) is carcinogenic and of major concern in groundwater. We collected sediment material from a contaminated anoxic aquifer in Sweden and investigated the immobilization of As by four commercial zero-valent iron (ZVI) particles. Solid-phase As and Fe speciation was assessed using X-ray absorption spectroscopy (XAS) and solution-phase As speciation using chromatographic separation. Without ZVI addition, arsenite dominated in solution and As(V) species in the solid phase. Adding ZVI caused a sharp increase in solution pH (9.3-9.8), favoring As oxidation despite a lowered redox potential. ZVI greatly improved As retention by complex binding of arsenate to the Fe(III) (hydr)oxides formed by ZVI corrosion. Uncoated ZVI, both in nano- and microscale, performed better than their sulfidated counterparts, partly due to occlusion of As by the Fe(III) (hydr)oxides formed. The effect of particle size (micro vs. nano ZVI) on As immobilization was small, likely because immobilization was related to the corrosion products formed, rather than the initial size of the particles. Our results provide a strong geochemical background for the application of ZVI particles to remove As in contaminated aquifers under anoxic conditions and illustrate that immobilization mechanisms can differ between ZVI in As spiked solutions and sediment suspensions. ENVIRONMENTAL IMPLICATION: Arsenic ranks first on the list by the US ATSDR of substances posing a threat to human health and the WHO considers groundwater the riskiest source for human intake of As. However, dealing with As contamination remains a scientific challenge. We studied the immobilization of groundwater As by commercially available ZVI particles at field-realistic conditions. Arsenic immobilization was highly efficient in most cases, and the results suggest this is a promising in situ strategy with long-term performance. Our results provide a strong geochemical background for using ZVI to remove As in contaminated anoxic aquifers.
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Affiliation(s)
- Thiago Augusto Formentini
- Department of Soil and Environment, Swedish University of Agricultural Sciences, P. O. Box 7014, SE-750 07 Uppsala, Sweden.
| | - Geert Cornelis
- Department of Soil and Environment, Swedish University of Agricultural Sciences, P. O. Box 7014, SE-750 07 Uppsala, Sweden
| | - Jon Petter Gustafsson
- Department of Soil and Environment, Swedish University of Agricultural Sciences, P. O. Box 7014, SE-750 07 Uppsala, Sweden
| | - Kathrin Leicht
- Department of Soil and Environment, Swedish University of Agricultural Sciences, P. O. Box 7014, SE-750 07 Uppsala, Sweden
| | - Charlotta Tiberg
- Swedish Geotechnical Institute (SGI), SE-581 93 Linköping, Sweden
| | - Britta Planer-Friedrich
- Environmental Geochemistry Group, Bayreuth Center for Ecology and Environmental Research (BAYCEER), Bayreuth University, 95440 Bayreuth, Germany
| | - Neal Durant
- Geosyntec Consultants, Inc, 10211 Wincopin Circle, 4th Floor, Columbia, MD 21044, USA
| | - Dimin Fan
- Geosyntec Consultants, Inc, 10211 Wincopin Circle, 4th Floor, Columbia, MD 21044, USA
| | - Dan B Kleja
- Department of Soil and Environment, Swedish University of Agricultural Sciences, P. O. Box 7014, SE-750 07 Uppsala, Sweden
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4
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Luin U, Arčon I, Valant M. Structure and Population of Complex Ionic Species in FeCl 2 Aqueous Solution by X-ray Absorption Spectroscopy. Molecules 2022; 27:642. [PMID: 35163907 PMCID: PMC8839570 DOI: 10.3390/molecules27030642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 11/16/2022] Open
Abstract
Technologies for mass production require cheap and abundant materials such as ferrous chloride (FeCl2). The literature survey shows the lack of experimental studies to validate theoretical conclusions related to the population of ionic Fe-species in the aqueous FeCl2 solution. Here, we present an in situ X-ray absorption study of the structure of the ionic species in the FeCl2 aqueous solution at different concentrations (1-4 molL-1) and temperatures (25-80 °C). We found that at low temperature and low FeCl2 concentration, the octahedral first coordination sphere around Fe is occupied by one Cl ion at a distance of 2.33 (±0.02) Å and five water molecules at a distance of 2.095 (±0.005) Å. The structure of the ionic complex gradually changes with an increase in temperature and/or concentration. The apical water molecule is substituted by a chlorine ion to yield a neutral Fe[Cl2(H2O)4]0. The observed substitutional mechanism is facilitated by the presence of the intramolecular hydrogen bonds as well as entropic reasons. The transition from the single charged Fe[Cl(H2O)5]+ to the neutral Fe[Cl2(H2O)4]0 causes a significant drop in the solution conductivity, which well correlates with the existing conductivity models.
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Affiliation(s)
- Uroš Luin
- Materials Research Laboratory, University of Nova Gorica, Vipavska 13, SI-5001 Nova Gorica, Slovenia; (U.L.); (I.A.)
| | - Iztok Arčon
- Materials Research Laboratory, University of Nova Gorica, Vipavska 13, SI-5001 Nova Gorica, Slovenia; (U.L.); (I.A.)
- Department of Low and Medium Energy Physics, J. Stefan Institute, Jamova 39, SI-1001 Ljubljana, Slovenia
| | - Matjaz Valant
- Materials Research Laboratory, University of Nova Gorica, Vipavska 13, SI-5001 Nova Gorica, Slovenia; (U.L.); (I.A.)
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5
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Boukar O, Fifen JJ, Nsangou M, Ghalila H, Conradie J. Structures and relative stability of hydrated ferrous ion clusters and temperature effects. NEW J CHEM 2021. [DOI: 10.1039/d1nj01849c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Structures of solvated ferrous ion clusters have been investigated in the singlet and quintet spin states of the ferrous ion. Relative stabilities of isomers are also discussed at different temperatures.
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Affiliation(s)
- Ousman Boukar
- Department of Physics
- Faculty of Science
- University of Maroua
- Cameroon
| | - Jean Jules Fifen
- Quantum Theory and Aplications Unit
- Department of Physics
- Faculty of Science
- The University of Ngaoundere
- Ngaoundere
| | - Mama Nsangou
- Department of Physics
- Faculty of Science
- University of Maroua
- Cameroon
- Quantum Theory and Aplications Unit
| | - Hassen Ghalila
- Faculty of Science
- University of Tunis El Manar
- Tunis
- Tunisia
| | - Jeanet Conradie
- Department of Chemistry
- University of the Free State
- Bloemfontein
- South Africa
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6
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Maire du Poset A, Zitolo A, Cousin F, Assifaoui A, Lerbret A. Evidence for an egg-box-like structure in iron(ii)–polygalacturonate hydrogels: a combined EXAFS and molecular dynamics simulation study. Phys Chem Chem Phys 2020; 22:2963-2977. [DOI: 10.1039/c9cp04065j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The coordination of Fe(ii) with polygalacturonic acid (polyGalA) in Fe(ii)–polyGalA hydrogels exhibits an octahedral geometry that follows the “egg-box model”.
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Affiliation(s)
| | - Andrea Zitolo
- Synchrotron SOLEIL
- L’Orme des Merisiers
- BP 48 St Aubin
- 91192 Gif-sur-Yvette
- France
| | - Fabrice Cousin
- Laboratoire Léon Brillouin
- Université Paris-Saclay
- CEA-Saclay
- 91191 Gif-sur-Yvette
- France
| | - Ali Assifaoui
- Univ. Bourgogne Franche-Comté
- AgroSup Dijon
- PAM UMR A 02.102
- F-21000 Dijon
- France
| | - Adrien Lerbret
- Univ. Bourgogne Franche-Comté
- AgroSup Dijon
- PAM UMR A 02.102
- F-21000 Dijon
- France
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7
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Novikova NN, Yakunin SN, Koval’chuk MV, Yur’eva EA, Stepina ND, Rogachev AV, Kremennaya MA, Yalovega GE, Kosmachevskaya OV, Topunov AF. Possibilities of X-Ray Absorption Spectroscopy in the Total External Reflection Geometry for Studying Protein Films on Liquids. CRYSTALLOGR REP+ 2019. [DOI: 10.1134/s1063774519060130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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8
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Structure of the nearest surrounding of ions in aqueous solutions of iron(III) chloride by x-ray diffraction method. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.02.099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Schwaab G, Sebastiani F, Havenith M. Untersuchung von Ionenhydratation und Ionenpaarbildung mittels THz‐Spektroskopie. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201805261] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum 44780 Bochum Deutschland
| | - Federico Sebastiani
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum 44780 Bochum Deutschland
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum 44780 Bochum Deutschland
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10
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Schwaab G, Sebastiani F, Havenith M. Ion Hydration and Ion Pairing as Probed by THz Spectroscopy. Angew Chem Int Ed Engl 2018; 58:3000-3013. [PMID: 30022575 DOI: 10.1002/anie.201805261] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/17/2018] [Indexed: 11/12/2022]
Abstract
Ion hydration is of pivotal importance for many fundamental processes. Various spectroscopic methods are used to study the retardation of the hydration bond dynamics in the vicinity of anions and cations. Here we introduce THz-FTIR spectroscopy as a powerful method to answer the open questions. We show through dissection of THz spectra that we can pinpoint characteristic absorption features that can be attributed to the rattling modes of strongly hydrating ions within their hydration cages as well as vibrationally induced charge fluctuations in the case of weakly hydrating ions. Further analysis yields information on anion-cation cooperativity, the size of the dynamic hydration shell, as well as the lifetimes of these collective ion-hydration water modes and their connecting thermal bath states. Our study provides evidence for a non-additive behavior, thus questioning the simplified Hofmeister model. THz spectroscopy enables ion pairing to be observed and quantified at a high salt concentration.
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Affiliation(s)
- Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Federico Sebastiani
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
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11
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Sessa F, Spezia R, D'Angelo P. Lutetium(iii) aqua ion: On the dynamical structure of the heaviest lanthanoid hydration complex. J Chem Phys 2017; 144:204505. [PMID: 27250314 DOI: 10.1063/1.4951714] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The structure and dynamics of the lutetium(iii) ion in aqueous solution have been investigated by means of a polarizable force field molecular dynamics (MD). An 8-fold square antiprism (SAP) geometry has been found to be the dominant configuration of the lutetium(iii) aqua ion. Nevertheless, a low percentage of 9-fold complexes arranged in a tricapped trigonal prism (TTP) geometry has been also detected. Dynamic properties have been explored by carrying out six independent MD simulations for each of four different temperatures: 277 K, 298 K, 423 K, 632 K. The mean residence time of water molecules in the first hydration shell at room temperature has been found to increase as compared to the central elements of the lanthanoid series in agreement with previous experimental findings. Water exchange kinetic rate constants at each temperature and activation parameters of the process have been determined from the MD simulations. The obtained structural and dynamical results suggest that the water exchange process for the lutetium(iii) aqua ion proceeds with an associative mechanism, in which the SAP hydration complex undergoes temporary structural changes passing through a 9-fold TTP intermediate. Such results are consistent with the water exchange mechanism proposed for heavy lanthanoid atoms.
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Affiliation(s)
- Francesco Sessa
- Dipartimento di Chimica, Università di Roma "La Sapienza," P. le A. Moro 5, 00185 Roma, Italy
| | - Riccardo Spezia
- CNRS, UMR 8587, Laboratoire Analyse et Modelisation Pour la Biologie et l'Environnement, Université d'Evry Val d'Essonne, Blvd. F. Mitterrand, 91025 Evry Cedex, France
| | - Paola D'Angelo
- Dipartimento di Chimica, Università di Roma "La Sapienza," P. le A. Moro 5, 00185 Roma, Italy
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Blazevic A, Orlowska E, Kandioller W, Jirsa F, Keppler BK, Tafili-Kryeziu M, Linert W, Krachler RF, Krachler R, Rompel A. Photoreduction of Terrigenous Fe-Humic Substances Leads to Bioavailable Iron in Oceans. Angew Chem Int Ed Engl 2016; 55:6417-22. [PMID: 27100573 PMCID: PMC4950011 DOI: 10.1002/anie.201600852] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 02/18/2016] [Indexed: 11/26/2022]
Abstract
Humic substances (HS) are important iron chelators responsible for the transport of iron from freshwater systems to the open sea, where iron is essential for marine organisms. Evidence suggests that iron complexed to HS comprises the bulk of the iron ligand pool in near-coastal waters and shelf seas. River-derived HS have been investigated to study their transport to, and dwell in oceanic waters. A library of iron model compounds and river-derived Fe-HS samples were probed in a combined X-ray absorption spectroscopy (XAS) and valence-to-core X-ray emission spectroscopy (VtC-XES) study at the Fe K-edge. The analyses performed revealed that iron complexation in HS samples is only dependent on oxygen-containing HS functional groups, such as carboxyl and phenol. The photoreduction mechanism of Fe(III) -HS in oceanic conditions into bioavailable aquatic Fe(II) forms, highlights the importance of river-derived HS as an iron source for marine organisms. Consequently, such mechanisms are a vital component of the upper-ocean iron biogeochemistry cycle.
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Affiliation(s)
- Amir Blazevic
- Institut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien, Althanstraße 14, 1090, Vienna, Austria
| | - Ewelina Orlowska
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 42, 1090, Vienna, Austria
| | - Wolfgang Kandioller
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 42, 1090, Vienna, Austria
| | - Franz Jirsa
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090, Vienna, Austria
| | - Bernhard K Keppler
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 42, 1090, Vienna, Austria
| | - Myrvete Tafili-Kryeziu
- Institut für Angewandte Synthesechemie, Technische Universität Wien, Getreidemarkt 9/163-AC, 1060, Vienna, Austria
| | - Wolfgang Linert
- Institut für Angewandte Synthesechemie, Technische Universität Wien, Getreidemarkt 9/163-AC, 1060, Vienna, Austria
| | - Rudolf F Krachler
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090, Vienna, Austria
| | - Regina Krachler
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Althanstraße 14, 1090, Vienna, Austria
| | - Annette Rompel
- Institut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien, Althanstraße 14, 1090, Vienna, Austria.
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13
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Blazevic A, Orlowska E, Kandioller W, Jirsa F, Keppler BK, Tafili‐Kryeziu M, Linert W, Krachler RF, Krachler R, Rompel A. Photoreduction of Terrigenous Fe-Humic Substances Leads to Bioavailable Iron in Oceans. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 128:6527-6532. [PMID: 27478277 PMCID: PMC4949668 DOI: 10.1002/ange.201600852] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 02/18/2016] [Indexed: 11/06/2022]
Abstract
Humic substances (HS) are important iron chelators responsible for the transport of iron from freshwater systems to the open sea, where iron is essential for marine organisms. Evidence suggests that iron complexed to HS comprises the bulk of the iron ligand pool in near-coastal waters and shelf seas. River-derived HS have been investigated to study their transport to, and dwell in oceanic waters. A library of iron model compounds and river-derived Fe-HS samples were probed in a combined X-ray absorption spectroscopy (XAS) and valence-to-core X-ray emission spectroscopy (VtC-XES) study at the Fe K-edge. The analyses performed revealed that iron complexation in HS samples is only dependent on oxygen-containing HS functional groups, such as carboxyl and phenol. The photoreduction mechanism of FeIII-HS in oceanic conditions into bioavailable aquatic FeII forms, highlights the importance of river-derived HS as an iron source for marine organisms. Consequently, such mechanisms are a vital component of the upper-ocean iron biogeochemistry cycle.
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Affiliation(s)
- Amir Blazevic
- Institut für Biophysikalische ChemieFakultät für ChemieUniversität WienAlthanstraße 141090ViennaAustria
| | - Ewelina Orlowska
- Institute of Inorganic ChemistryFaculty of ChemistryUniversity of ViennaWähringer Straße 421090ViennaAustria
| | - Wolfgang Kandioller
- Institute of Inorganic ChemistryFaculty of ChemistryUniversity of ViennaWähringer Straße 421090ViennaAustria
| | - Franz Jirsa
- Institute of Inorganic ChemistryFaculty of ChemistryUniversity of ViennaAlthanstraße 141090ViennaAustria
| | - Bernhard K. Keppler
- Institute of Inorganic ChemistryFaculty of ChemistryUniversity of ViennaWähringer Straße 421090ViennaAustria
| | - Myrvete Tafili‐Kryeziu
- Institut für Angewandte SynthesechemieTechnische Universität WienGetreidemarkt 9/163-AC1060ViennaAustria
| | - Wolfgang Linert
- Institut für Angewandte SynthesechemieTechnische Universität WienGetreidemarkt 9/163-AC1060ViennaAustria
| | - Rudolf F. Krachler
- Institute of Inorganic ChemistryFaculty of ChemistryUniversity of ViennaAlthanstraße 141090ViennaAustria
| | - Regina Krachler
- Institute of Inorganic ChemistryFaculty of ChemistryUniversity of ViennaAlthanstraße 141090ViennaAustria
| | - Annette Rompel
- Institut für Biophysikalische ChemieFakultät für ChemieUniversität WienAlthanstraße 141090ViennaAustria
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14
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Ma K, Zhao L. The Opposite Effect of Metal Ions on Short-/Long-Range Water Structure: A Multiple Characterization Study. Int J Mol Sci 2016; 17:ijms17050602. [PMID: 27120598 PMCID: PMC4881438 DOI: 10.3390/ijms17050602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/14/2016] [Accepted: 04/18/2016] [Indexed: 12/21/2022] Open
Abstract
Inorganic electrolyte solutions are very important in our society as they dominate many biochemical and geochemical processes. Herein, an in-depth study was performed to illustrate the ion-induced effect on water structure by coupling NMR, viscometer, Raman and Molecular Dynamic (MD) simulations. The NMR coefficient (BNMR) and diffusion coefficient (D) from NMR, and viscosity coefficient (Bvis) from a viscometer all proved that dissolved metal ions are capable of enhancing the association degree of adjacent water molecules, and the impact on water structure decreased in the order of Cr3+ > Fe3+ > Cu2+ > Zn2+. This regularity was further evidenced by Raman analysis; however, the deconvoluted Raman spectrum indicated the decrease in high association water with salt concentration and the increase in low association water before 200 mmol·L−1. By virtue of MD simulations, the opposite changing manner proved to be the result of the opposite effect on short-/long-range water structure induced by metal ions. Our results may help to explain specific protein denaturation induced by metal ions.
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Affiliation(s)
- Kai Ma
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
| | - Lin Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
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16
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Messner CB, Lutz OMD, Rainer M, Huck CW, Hofer TS, Rode BM, Bonn GK. Structure and dynamics of chromatographically relevant Fe(III)-chelates. J Phys Chem B 2014; 118:12232-8. [PMID: 25301257 DOI: 10.1021/jp505193y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Immobilized metal ion affinity chromatography (IMAC) is an important chromatographic technique for biomolecules. In order to get a detailed understanding of the hydration of immobilized Fe(III), complexes of Fe(III) with methyl substituted iminodiacetate ([Fe(MSIDA)(H2O)3](+)) as well as with methyl substituted nitrilotriacetate ([Fe(MSNTA)(H2O)2]) were simulated in aqueous solutions with the quantum mechanical charge field molecular dynamics (QMCF MD) approach. The simulations were carried out at the Hartree-Fock (HF) level of theory, since cluster calculations at the HF, MP2, and B3LYP levels of theory showed that this method results in a good compromise between computational effort and accuracy. None of the coordinating water molecules were exchanged during the simulation period of 15 ps. The Fe-OH2O bond distances as well as the Fe-OH2O stretching motions differed among the coordinating water molecules, indicating different bond strengths. For the water molecules in the second hydration layer, mean residence times of 2.7 and 1.9 ps were obtained for [Fe(MSIDA)(H2O)3](+) and [Fe(MSNTA)(H2O)2], respectively. Furthermore, infrared measurements were carried out to characterize the most prominent bond features of aqueous Fe(III)-NTA and to discuss these results in conjunction with the computationally derived frequencies.
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Affiliation(s)
- Christoph B Messner
- Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innsbruck , Innrain 80-82, 6020 Innsbruck, Austria
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Garino C, Borfecchia E, Gobetto R, van Bokhoven JA, Lamberti C. Determination of the electronic and structural configuration of coordination compounds by synchrotron-radiation techniques. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.03.027] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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18
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Mellmann D, Barsch E, Bauer M, Grabow K, Boddien A, Kammer A, Sponholz P, Bentrup U, Jackstell R, Junge H, Laurenczy G, Ludwig R, Beller M. Base‐Free Non‐Noble‐Metal‐Catalyzed Hydrogen Generation from Formic Acid: Scope and Mechanistic Insights. Chemistry 2014; 20:13589-602. [DOI: 10.1002/chem.201403602] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Indexed: 11/07/2022]
Affiliation(s)
- Dörthe Mellmann
- Leibniz Institute for Catalysis, Albert‐Einstein‐Straße 29a, 18059 Rostock (Germany), Fax: (+49) 381‐1281‐5000
| | - Enrico Barsch
- Department of Physical Chemistry, University of Rostock, Dr.‐Lorenz‐Weg 1, 18059 Rostock (Germany), Fax: (+49) 381‐498‐6524
| | - Matthias Bauer
- Department of Chemistry, University of Paderborn, Warburger Straße 100, 33098 Paderborn (Germany)
| | - Kathleen Grabow
- Leibniz Institute for Catalysis, Albert‐Einstein‐Straße 29a, 18059 Rostock (Germany), Fax: (+49) 381‐1281‐5000
| | - Albert Boddien
- Leibniz Institute for Catalysis, Albert‐Einstein‐Straße 29a, 18059 Rostock (Germany), Fax: (+49) 381‐1281‐5000
| | - Anja Kammer
- Leibniz Institute for Catalysis, Albert‐Einstein‐Straße 29a, 18059 Rostock (Germany), Fax: (+49) 381‐1281‐5000
| | - Peter Sponholz
- Leibniz Institute for Catalysis, Albert‐Einstein‐Straße 29a, 18059 Rostock (Germany), Fax: (+49) 381‐1281‐5000
| | - Ursula Bentrup
- Leibniz Institute for Catalysis, Albert‐Einstein‐Straße 29a, 18059 Rostock (Germany), Fax: (+49) 381‐1281‐5000
| | - Ralf Jackstell
- Leibniz Institute for Catalysis, Albert‐Einstein‐Straße 29a, 18059 Rostock (Germany), Fax: (+49) 381‐1281‐5000
| | - Henrik Junge
- Leibniz Institute for Catalysis, Albert‐Einstein‐Straße 29a, 18059 Rostock (Germany), Fax: (+49) 381‐1281‐5000
| | - Gábor Laurenczy
- École Polytechnique Fédérale de Lausanne (EPFL), Institut des Sciences et Ingénierie Chimiques, 1015 Lausanne (Switzerland)
| | - Ralf Ludwig
- Department of Physical Chemistry, University of Rostock, Dr.‐Lorenz‐Weg 1, 18059 Rostock (Germany), Fax: (+49) 381‐498‐6524
| | - Matthias Beller
- Leibniz Institute for Catalysis, Albert‐Einstein‐Straße 29a, 18059 Rostock (Germany), Fax: (+49) 381‐1281‐5000
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19
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Zitolo A, Migliorati V, Aquilanti G, D’Angelo P. On the possibility of using XANES to investigate bromide-based ionic liquids. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2013.10.086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Olszewski W, Szymański K, Satuła D, Kalska-Szostko B. Structure of iron ions in some acetone based electrolytes. J Phys Chem A 2013; 117:2190-4. [PMID: 23425339 DOI: 10.1021/jp400556d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
X-ray absorption, Mössbauer, and Raman spectroscopy were combined to determine the local environment of iron ions in acetone based solutions of FeCl2. It is shown that part of the Fe(II) ions change their oxidation state, accompanied by symmetry change from octahedral Fe(H2O)6(2+) to tetrahedral [FeCl4](-) at large acetone concentrations. The ratio of Fe(II)/Fe(III) determined by Mössbauer spectroscopy agrees well with that determined by the X-ray absorption studies. Raman measurements confirm quantitative estimations of [FeCl4](-) species in acetone rich solutions.
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Affiliation(s)
- Wojciech Olszewski
- Faculty of Physics, University of Bialystok, ul. Lipowa 41, 15-424 Białystok, Poland.
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21
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Haider S, Di Tommaso D, de Leeuw NH. Density functional theory simulations of the structure, stability and dynamics of iron sulphide clusters in water. Phys Chem Chem Phys 2013; 15:4310-9. [DOI: 10.1039/c3cp43560a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Torapava N, Radkevich A, Persson I, Davydov D, Eriksson L. Formation of a heteronuclear hydrolysis complex in the ThIV–FeIII system. Dalton Trans 2012; 41:4451-9. [DOI: 10.1039/c2dt30058c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Olszewski W, Szymański K, Zaleski P, Zając DA. X-ray Absorption near Edge Structure and Extended X-ray Absorption Fine Structure Analysis of Fe(II) Aqueous and Acetone Solutions. J Phys Chem A 2011; 115:13420-4. [PMID: 21995586 DOI: 10.1021/jp207587u] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Wojciech Olszewski
- Faculty of Physics, University of Bialystok, Lipowa 41, 15-424 Białystok, Poland
| | - Krzysztof Szymański
- Faculty of Physics, University of Bialystok, Lipowa 41, 15-424 Białystok, Poland
| | - Piotr Zaleski
- Faculty of Physics, University of Bialystok, Lipowa 41, 15-424 Białystok, Poland
| | - Dariusz A. Zając
- Deutsches Elektronen-Synchrotron-Hasylab, Notkestrasse 85, 22607 Hamburg, Germany
- H. Niewodniczański Institute of Nuclear Physics of PAN, Radzikowskiego 152, 31-342 Kraków, Poland
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Moin ST, Hofer TS, Pribil AB, Randolf BR, Rode BM. A quantum mechanical charge field molecular dynamics study of Fe(2+) and Fe(3+) ions in aqueous solutions. Inorg Chem 2010; 49:5101-6. [PMID: 20441160 DOI: 10.1021/ic1002572] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) simulations have been performed for aqueous solutions of Fe(2+) and Fe(3+) ions at the Hartree-Fock level of theory to describe and compare their structural and dynamical behavior. The structural features of both hydrated ions are characterized by radial distribution functions that give the maximum probability of the ion-O distance for Fe(2+) and Fe(3+) ions at 2.15 and 2.03 A, respectively. The angular distribution functions of both ions prove the octahedral arrangement of six water ligands, whereas the second shells of these ions differ. Both ions show influence on the water molecules beyond the second shells. The structure-forming abilities of both ions are visible from the ligand mean residence times and ion-O stretching frequencies evaluated for both ions. The substantially improved data obtained from these QMCF-MD simulations show better correlation with available experimental results than the conventional quantum mechanics/molecular mechanics molecular dynamics (QM/MM MD) approaches with one hydration shell treated by quantum mechanics.
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Affiliation(s)
- Syed Tarique Moin
- Theoretical Chemistry Division, Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
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D'Angelo P, Zitolo A, Migliorati V, Persson I. Analysis of the Detailed Configuration of Hydrated Lanthanoid(III) Ions in Aqueous Solution and Crystalline Salts by Using K- and L3-Edge XANES Spectroscopy. Chemistry 2010; 16:684-92. [DOI: 10.1002/chem.200900122] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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D’Angelo P, Zitolo A, Migliorati V, Mancini G, Persson I, Chillemi G. Structural Investigation of Lanthanoid Coordination: a Combined XANES and Molecular Dynamics Study. Inorg Chem 2009; 48:10239-48. [DOI: 10.1021/ic901264e] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paola D’Angelo
- Department of Chemistry, University of Rome “La Sapienza”, P. le A. Moro 5, 00185 Roma, Italy
| | - Andrea Zitolo
- Department of Chemistry, University of Rome “La Sapienza”, P. le A. Moro 5, 00185 Roma, Italy
| | - Valentina Migliorati
- Department of Chemistry, University of Rome “La Sapienza”, P. le A. Moro 5, 00185 Roma, Italy
| | - Giordano Mancini
- CASPUR, Inter-University Consortium for Supercomputing in Research, via dei Tizii 6b, 00185 Roma, Italy
| | - Ingmar Persson
- Department of Chemistry, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Giovanni Chillemi
- CASPUR, Inter-University Consortium for Supercomputing in Research, via dei Tizii 6b, 00185 Roma, Italy
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Jeanson A, Berthon C, Coantic S, Den Auwer C, Floquet N, Funke H, Guillaneux D, Hennig C, Martinez J, Moisy P, Petit S, Proux O, Quémeneur E, Lorenzo Solari P, Subra G. The role of aspartyl-rich pentapeptides in comparative complexation of actinide(iv) and iron(iii). Part 1. NEW J CHEM 2009. [DOI: 10.1039/b813523a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Ko YS, Jang HT, Ahn WS. Hydrothermal synthesis and characterization of Fe(III)-substituted mordenites. KOREAN J CHEM ENG 2008. [DOI: 10.1007/s11814-008-0211-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Karlsson T, Persson P, Skyllberg U, Mörth CM, Giesler R. Characterization of iron(III) in organic soils using extended X-ray absorption fine structure spectroscopy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:5449-5454. [PMID: 18754459 DOI: 10.1021/es800322j] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The distribution of different iron (Fe) species in soils, sediments, and surface waters has a large influence on the mobility and availability of Fe, other nutrients, and potentially toxic trace elements. However, the knowledge about the specific forms of Fe that occurs in these systems is limited, especially regarding associations of Fe with natural organic matter (NOM). In this study, extended X-ray absorption fine structure (EXAFS) spectroscopy was used to characterize Fe(III) in organic soils (pH 4.6-6.0) with varying natural Fe content. The EXAFS data were subjected to wavelet transform analysis, to facilitate the identification of the nature of backscattering atoms, and to conventional EXAFS data fitting. The collective results showed the existence of two pools of iron: mononuclear Fe(III)-NOM complexes and precipitated Fe(III) (hydr)oxides. In the soil with lowest pH (4.6) and Fe content mononuclear organic complexes were the completely dominating fraction whereas in soils with higher pH and Fe content increasing amounts of Fe (hydr)oxides were detected. These results are of environmental importance, as the different iron pools most likely have markedly different reactivities.
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van Schaik JWJ, Persson I, Kleja DB, Gustafsson JP. EXAFS study on the reactions between iron and fulvic acid in acid aqueous solutions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:2367-2373. [PMID: 18504967 DOI: 10.1021/es072092z] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Iron(III) competes with trace metals for binding sites on organic ligands. We used X-ray absorption fine structure (EXAFS) spectroscopy to determine the binding mode and oxidation state of iron in solutions initially containing only iron(III) and fulvic acid at pHs 2 and 4. EXAFS spectra were recorded at different times after sample preparation. Iron was octahedrally configured with inner-sphere Fe-O interactions at 1.98-2.10 A, depending on the oxidation state of iron. Iron(III) formed complexes with fulvic acid within 15 min. Iron(III) was reduced to iron(II) with time at pH 2, whereas no significant reduction occurred at pH 4. No signs of dimeric/trimeric hydrolysis products were found in any of the solution samples (<0.45 microm). However, the isolated precipitate of the pH 2 sample (>0.45 microm) showed Fe...Fe distances, indicating the presence of tightly packed iron(III) trimers and/or clusters of corner-sharing octahedra. It is suggested that the binding mode of iron(III) to fulvic acid at low pH may be phase-dependent: in solution mononuclear complexes predominate, whereas in the solid phase hydrolyzed polynuclear iron(III) complexes form, even at very low pH values. The observed pH dependence of iron(III) reduction was consistent with expected results based on thermodynamic calculations for model ligands.
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Affiliation(s)
- Joris W J van Schaik
- Department of Soil Sciences, Swedish University of Agricultural Sciences, Box 7014, SE-750 07 Uppsala, Sweden.
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A structural study of the hydrated and the dimethylsulfoxide, N,N′-dimethylpropyleneurea, and N,N-dimethylthioformamide solvated iron(II) and iron(III) ions in solution and solid state. Inorganica Chim Acta 2007. [DOI: 10.1016/j.ica.2006.09.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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32
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Gustafsson JP, Persson I, Kleja DB, Van Schaik JWJ. Binding of iron(III) to organic soils: EXAFS spectroscopy and chemical equilibrium modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:1232-7. [PMID: 17593724 DOI: 10.1021/es0615730] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The complexation of iron(III) to soil organic matter is important for the binding of trace metals in natural environments because of competition effects. In this study, we used extended X-ray absorption fine structure (EXAFS) spectroscopy to characterize the binding mode for iron(III) in two soil samples from organic mor layers, one of which was also treated with iron(III). In most cases the EXAFS spectra had three significant contributions, inner-core Fe-O/N interactions at about 2.02(2) A, Fe-C interactions in the second scattering shell at 3.00(4) A, and a mean Fe-Fe distance at 3.37(3) A. One untreated sample showed features typical for iron (hydr)oxides; however, after treatment of iron(III) the EXAFS spectrum was dominated by organically complexed iron. The presence of a Fe-Fe distance in all samples showed that the major part of the organically complexed iron was hydrolyzed, most likely in a mixture of complexes with an inner core of (O5Fe)2O and (O5Fe)3O. These results were used to constrain a model for metal-humic complexation, the Stockholm Humic Model (SHM). The model was able to describe iron(III) binding verywell at low pH considering only one dimeric iron(III)-humic complex. The competition effect on trace metals was also well described.
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Affiliation(s)
- Jon Petter Gustafsson
- Department of Land and Water Resources Engineering, Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
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De Abreu HA, Guimarães L, Duarte HA. Density-Functional Theory Study of Iron(III) Hydrolysis in Aqueous Solution. J Phys Chem A 2006; 110:7713-8. [PMID: 16774219 DOI: 10.1021/jp060714h] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fe(III) hydrolysis in aqueous solution has been investigated using density-functional methods (DFT). All possible structures arising from different tautomers and multiplicities have been calculated. The solvation energy has been estimated using the UAHF-PCM method. The hydrolysis free energies have been estimated and compared with the available experimental data. The different hydrolysis species have distinct geometries and electronic structures. We have shown that improvement of theory level in calculating the electronic energy does not necessarily improve the estimated free energies in aqueous solution since the UAHF-PCM is a simple method that neglects specific interactions with the solvent. Therefore, it is important to have the correct balance between theory level used in the electronic calculation and the UAHF-PCM. The PBE/TZVP/UAHF-PCM method has been found to describe correctly the hydrolysis energies of Fe(III), deviating about 3.0 kcal mol(-1) from experimental values.
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Affiliation(s)
- Heitor Avelino De Abreu
- Grupo de Pesquisa em Química Inorgânica Teórica, Departamento de Química, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31.270-901, Brazil
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Hayakawa K, Hatada K, D'Angelo P, Della Longa S, Natoli CR, Benfatto M. Full Quantitative Multiple-Scattering Analysis of X-ray Absorption Spectra: Application to Potassium Hexacyanoferrat(II) and -(III) Complexes. J Am Chem Soc 2004; 126:15618-23. [PMID: 15563192 DOI: 10.1021/ja045561v] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A recently developed method to the full quantitative analysis of the XAS spectra extending from the absorption edge to the high-energy region is presented. This method is based on the use of two independent approaches to the analysis of the EXAFS and XANES data, the well-known GNXAS and the newly developed MXAN procedures. Herein, we report the application of this technique to two iron complexes of known structure where multiple-scattering effects are prominent, the potassium hexacyanoferrat(II) and -(III) crystals and aqueous solutions. The structural parameters obtained from refinements using the two methods are equal and compare quite well with crystallographic values. Small discrepancies between the experimental and calculated XANES spectra have been observed, and their origin has been investigated in the framework of non-muffin-tin correction. The ligand dependence of the theoretical spectra has been also examined. Analysis of the whole energy range of the XAS spectra has been found to be useful in elucidating both the type of ligands and the geometry of iron sites. These results are of particular use in studying the geometrical environment of metallic sites in proteins and complexes of chemical interest.
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Affiliation(s)
- Kuniko Hayakawa
- Laboratori Nazionali di Frascati, INFN, CP13, 00044 Frascati, Italy
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D'Angelo P, Petit PE, Pavel NV. Double-Electron Excitation Channels at the Ca2+ K-Edge of Hydrated Calcium Ion. J Phys Chem B 2004. [DOI: 10.1021/jp048511l] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paola D'Angelo
- Dipartimento di Chimica, Università di Roma “La Sapienza”, P.O. Box 34 - Roma 62, Pzz.le A. Moro 5, I-00185 Roma, Italy, INFM UdF Camerino, Italy, and ESRF, BP 220, F-38043 Grenoble Cedex, France
| | - Pierre-Emmanuel Petit
- Dipartimento di Chimica, Università di Roma “La Sapienza”, P.O. Box 34 - Roma 62, Pzz.le A. Moro 5, I-00185 Roma, Italy, INFM UdF Camerino, Italy, and ESRF, BP 220, F-38043 Grenoble Cedex, France
| | - Nicolae Viorel Pavel
- Dipartimento di Chimica, Università di Roma “La Sapienza”, P.O. Box 34 - Roma 62, Pzz.le A. Moro 5, I-00185 Roma, Italy, INFM UdF Camerino, Italy, and ESRF, BP 220, F-38043 Grenoble Cedex, France
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