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Murphy GL, Gericke R, Gilson S, Bazarkina EF, Rossberg A, Kaden P, Thümmler R, Klinkenberg M, Henkes M, Kegler P, Svitlyk V, Marquardt J, Lender T, Hennig C, Kvashnina KO, Huittinen N. Deconvoluting Cr states in Cr-doped UO 2 nuclear fuels via bulk and single crystal spectroscopic studies. Nat Commun 2023; 14:2455. [PMID: 37117177 PMCID: PMC10147638 DOI: 10.1038/s41467-023-38109-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 04/13/2023] [Indexed: 04/30/2023] Open
Abstract
Cr-doped UO2 is a leading accident tolerant nuclear fuel where the complexity of Cr chemical states in the bulk material has prevented acquisition of an unequivocal understanding of the redox chemistry and mechanism for incorporation of Cr in the UO2 matrix. To resolve this, we have used electron paramagnetic resonance, high energy resolution fluorescence detection X-ray absorption near energy structure and extended X-ray absorption fine structure spectroscopic measurements to examine Cr-doped UO2 single crystal grains and bulk material. Ambient condition measurements of the single crystal grains, which have been mechanically extracted from bulk material, indicated Cr is incorporated substitutionally for U+4 in the fluorite lattice as Cr+3 with formation of additional oxygen vacancies. Bulk material measurements reveal the complexity of Cr states, where metallic Cr (Cr0) and oxide related Cr+2 and Cr+32O3 were identified and attributed to grain boundary species and precipitates, with concurrent (Cr+3xU+41-x)O2-0.5x lattice matrix incorporation. The deconvolution of chemical states via crystal vs. powder measurements enables the understanding of discrepancies in literature whilst providing valuable direction for safe continued use of Cr-doped UO2 fuels for nuclear energy generation.
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Affiliation(s)
- Gabriel L Murphy
- Institute of Energy and Climate Research (IEK-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany.
| | - Robert Gericke
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Sara Gilson
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Elena F Bazarkina
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
- The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble, Cedex 9, France
| | - André Rossberg
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
- The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble, Cedex 9, France
| | - Peter Kaden
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Robert Thümmler
- Institute of Energy and Climate Research (IEK-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Martina Klinkenberg
- Institute of Energy and Climate Research (IEK-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Maximilian Henkes
- Institute of Energy and Climate Research (IEK-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Philip Kegler
- Institute of Energy and Climate Research (IEK-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Volodymyr Svitlyk
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
- The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble, Cedex 9, France
| | - Julien Marquardt
- Institut für Geowissenschaften, Goethe-Universität Frankfurt, 60438, Frankfurt am Main, Germany
| | - Theresa Lender
- Institut für Kristallographie, RWTH Aachen University, 52066, Aachen, Germany
| | - Christoph Hennig
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
- The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble, Cedex 9, France
| | - Kristina O Kvashnina
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
- The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043, Grenoble, Cedex 9, France
| | - Nina Huittinen
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany.
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2
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Saurette EM, Frinfrock YZ, Verbuyst B, Blowes DW, McBeth JM, Ptacek CJ. Improved precision in As speciation analysis with HERFD-XANES at the As K-edge: the case of As speciation in mine waste. JOURNAL OF SYNCHROTRON RADIATION 2022; 29:1198-1208. [PMID: 36073878 PMCID: PMC9455218 DOI: 10.1107/s1600577522007068] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 07/09/2022] [Indexed: 06/15/2023]
Abstract
High-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge spectroscopy (XANES) is a spectroscopic method that allows for increased spectral feature resolution, and greater selectivity to decrease complex matrix effects compared with conventional XANES. XANES is an ideal tool for speciation of elements in solid-phase environmental samples. Accurate speciation of As in mine waste materials is important for understanding the mobility and toxicity of As in near-surface environments. In this study, linear combination fitting (LCF) was performed on synthetic spectra generated from mixtures of eight measured reference compounds for both HERFD-XANES and transmission-detected XANES to evaluate the improvement in quantitative speciation with HERFD-XANES spectra. The reference compounds arsenolite (As2O3), orpiment (As2S3), getchellite (AsSbS3), arsenopyrite (FeAsS), kaňkite (FeAsO4·3.5H2O), scorodite (FeAsO4·2H2O), sodium arsenate (Na3AsO4), and realgar (As4S4) were selected for their importance in mine waste systems. Statistical methods of principal component analysis and target transformation were employed to determine whether HERFD improves identification of the components in a dataset of mixtures of reference compounds. LCF was performed on HERFD- and total fluorescence yield (TFY)-XANES spectra collected from mine waste samples. Arsenopyrite, arsenolite, orpiment, and sodium arsenate were more accurately identified in the synthetic HERFD-XANES spectra compared with the transmission-XANES spectra. In mine waste samples containing arsenopyrite and either scorodite or kaňkite, LCF with HERFD-XANES measurements resulted in fits with smaller R-factors than concurrently collected TFY measurements. The improved accuracy of HERFD-XANES analysis may provide enhanced delineation of As phases controlling biogeochemical reactions in mine wastes, contaminated soils, and remediation systems.
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Affiliation(s)
- Emily M. Saurette
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, Canada
| | - Y. Zou Frinfrock
- Structural Biology Center, Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Brent Verbuyst
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, Canada
| | - David W. Blowes
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, Canada
| | - Joyce M. McBeth
- Department of Geology, University of Regina, Regina, SK, Canada
| | - Carol J. Ptacek
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, Canada
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3
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James AK, Dolgova NV, Nehzati S, Korbas M, Cotelesage JJH, Sokaras D, Kroll T, O’Donoghue JL, Watson GE, Myers GJ, Pickering IJ, George GN. Molecular Fates of Organometallic Mercury in Human Brain. ACS Chem Neurosci 2022; 13:1756-1768. [PMID: 35543423 PMCID: PMC9977140 DOI: 10.1021/acschemneuro.2c00166] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Mercury is ubiquitous in the environment, with rising levels due to pollution and climate change being a current global concern. Many mercury compounds are notorious for their toxicity, with the potential of organometallic mercury compounds for devastating effects on the structures and functions of the central nervous system being of particular concern. Chronic exposure of human populations to low levels of methylmercury compounds occurs through consumption of fish and other seafood, although the health consequences, if any, from this exposure remain controversial. We have used high energy resolution fluorescence detected X-ray absorption spectroscopy to determine the speciation of mercury and selenium in human brain tissue. We show that the molecular fate of mercury differs dramatically between individuals who suffered acute organometallic mercury exposure (poisoning) and individuals with chronic low-level exposure from a diet rich in marine fish. For long-term low-level methylmercury exposure from fish consumption, mercury speciation in brain tissue shows methylmercury coordinated to an aliphatic thiolate, resembling the coordination environment observed in marine fish. In marked contrast, for short-term high-level exposure, we observe the presence of biologically less available mercuric selenide deposits, confirmed by X-ray fluorescence imaging, as well as mercury(II)-bis-thiolate complexes, which may be signatures of severe poisoning in humans. These differences between low-level and high-level exposures challenge the relevance of studies involving acute exposure as a proxy for low-level chronic exposure.
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Affiliation(s)
- Ashley K. James
- Toxicology Centre, 44 Campus Drive, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada.,Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Natalia V. Dolgova
- Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Susan Nehzati
- Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Malgorzata Korbas
- Canadian Light Source, 44 Innovation Blvd, Saskatoon, Saskatchewan S7N 2V3, Canada
| | - Julien J. H. Cotelesage
- Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Thomas Kroll
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - John L. O’Donoghue
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA
| | - Gene E. Watson
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA.,Eastman Institute for Oral Health, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA
| | - Gary J. Myers
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA.,Departments of Neurology and Pediatrics, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA
| | - Ingrid J. Pickering
- Toxicology Centre, 44 Campus Drive, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada.,Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada.,Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9, Canada.,Corresponding Authors: Ingrid J. Pickering – Department of Geological Sciences, Toxicology Centre, and Department of Chemistry, University of Saskatchewan, Saskatoon S7N 5E2, Canada; , Graham N. George – Department of Geological Sciences, Toxicology Centre, and Department of Chemistry, University of Saskatchewan, Saskatoon S7N 5E2, Canada;
| | - Graham N. George
- Toxicology Centre, 44 Campus Drive, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada.,Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada.,Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9, Canada.,Corresponding Authors: Ingrid J. Pickering – Department of Geological Sciences, Toxicology Centre, and Department of Chemistry, University of Saskatchewan, Saskatoon S7N 5E2, Canada; , Graham N. George – Department of Geological Sciences, Toxicology Centre, and Department of Chemistry, University of Saskatchewan, Saskatoon S7N 5E2, Canada;
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4
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Kasem MR, Nakahira Y, Yamaoka H, Matsumoto R, Yamashita A, Ishii H, Hiraoka N, Takano Y, Goto Y, Mizuguchi Y. Robustness of superconductivity to external pressure in high-entropy-alloy-type metal telluride AgInSnPbBiTe 5. Sci Rep 2022; 12:7789. [PMID: 35552481 PMCID: PMC9098454 DOI: 10.1038/s41598-022-11862-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 04/26/2022] [Indexed: 11/17/2022] Open
Abstract
High-entropy-alloy (HEA) superconductors are a new class of disordered superconductors. However, commonality of superconducting characteristics of HEA materials is unclear. Here, we have investigated the crystal and electronic structure, and the robustness of superconducting states in a HEA-type metal telluride (MTe; M = Ag, In, Sn, Pb, Bi) under high pressure, and the results were compared with the pressure effects for a middle-entropy system (AgPbBiTe3) and a reference system of PbTe. When the crystal structure is CsCl-type, all phases show superconductivity under high pressure but exhibit different pressure dependences of the transition temperature (Tc). For PbTe, its Tc decreases with pressure. In contrast, the Tc of HEA-type AgInSnPbBiTe5 is almost independent of pressure, for pressures ranging from 13.0 to 35.1 GPa. Those results suggest that the robustness of superconductivity to external pressure is linked to the configurational entropy of mixing at the M site in MTe. Since the trend is quite similar to previous work on a HEA (Ti–Zr–Hf–Nb–Ta), where the robustness of superconductivity was observed up to ~ 200 GPa, we propose that the robustness of superconductivity under high pressure would be a universal feature in HEA-type superconductors.
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Affiliation(s)
- Md Riad Kasem
- Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, 192-0397, Japan
| | - Yuki Nakahira
- Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, 192-0397, Japan
| | | | - Ryo Matsumoto
- International Center for Young Scientists (ICYS), National Institute for Materials Science, Tsukuba, Ibaraki, 305-0047, Japan.,International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, Tsukuba, Ibaraki, 305-0047, Japan
| | - Aichi Yamashita
- Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, 192-0397, Japan
| | - Hirofumi Ishii
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Nozomu Hiraoka
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Yoshihiko Takano
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, Tsukuba, Ibaraki, 305-0047, Japan
| | - Yosuke Goto
- Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, 192-0397, Japan
| | - Yoshikazu Mizuguchi
- Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, 192-0397, Japan.
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5
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Mukhacheva AA, Asanova T, Ryzhikov MR, Sukhikh TS, Kompankov NB, Yanshole VV, Berezin AS, Gushchin AL, Abramov PA, Sokolov MN. Keggin-type polyoxometalate 1 : 1 complexes of Pb(II) and Bi(III): experimental, theoretical and luminescence studies. Dalton Trans 2021; 50:6913-6922. [PMID: 33928982 DOI: 10.1039/d1dt00499a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Bi3+ and Pb2+ uptake by a monolacunary Keggin-type [PW11O39]7- anion leads to the formation of [PW11O39Bi]4- and [PW11O39Pb]5- complexes with a stereochemically active lone pair at the incorporated heterometal. The two complexes were isolated as (TBA)4[PW11O39Bi] (1) and (TBA)5[PW11O39Pb] (2) and characterized by 31P and 183W NMR spectroscopy, high-resolution electrospray mass-spectrometry (HR-ESI-MS) and cyclic voltammetry (CV). EXAFS and XANES data confirm the unchanged oxidation state and ψ-square pyramidal geometry of Bi3+ and Pb2+ in 1 and 2. DFT calculations were used in order to (i) confirm the absence of ligands attached to the heterometal sites in both complexes and localize the lone pair, and (ii) assign all signals in the 183W NMR spectra. Complexes 1 and 2 demonstrate photoluminescence (PL). A reversible change in the PL spectra of both complexes in the presence of water vapor has been detected. On the contrary, PL data for sandwich-type ((CH3)4N)4K3[H4(PW11O39)2Bi]·25H2O (3) do not show sensitivity to water vapor.
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Affiliation(s)
- Anna A Mukhacheva
- Nikolaev Institute of Inorganic Chemistry, 3 Akad. Lavrentiev Ave. 630090, Russia.
| | - Tatiana Asanova
- Nikolaev Institute of Inorganic Chemistry, 3 Akad. Lavrentiev Ave. 630090, Russia.
| | - Maxim R Ryzhikov
- Nikolaev Institute of Inorganic Chemistry, 3 Akad. Lavrentiev Ave. 630090, Russia.
| | - Taisiya S Sukhikh
- Nikolaev Institute of Inorganic Chemistry, 3 Akad. Lavrentiev Ave. 630090, Russia.
| | - Nikolay B Kompankov
- Nikolaev Institute of Inorganic Chemistry, 3 Akad. Lavrentiev Ave. 630090, Russia.
| | - Vadim V Yanshole
- International Tomography Center, Institutskaya str. 3a, 630090, Novosibirsk, Russia and Novosibirsk State University, Pirogova str. 1, 630090, Novosibirsk, Russia
| | - Alexey S Berezin
- Nikolaev Institute of Inorganic Chemistry, 3 Akad. Lavrentiev Ave. 630090, Russia.
| | - Artem L Gushchin
- Nikolaev Institute of Inorganic Chemistry, 3 Akad. Lavrentiev Ave. 630090, Russia.
| | - Pavel A Abramov
- Nikolaev Institute of Inorganic Chemistry, 3 Akad. Lavrentiev Ave. 630090, Russia.
| | - Maxim N Sokolov
- Nikolaev Institute of Inorganic Chemistry, 3 Akad. Lavrentiev Ave. 630090, Russia.
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6
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Asakura H, Tanaka T. Recent Applications of X-ray Absorption Spectroscopy in Combination with High Energy Resolution Fluorescence Detection. CHEM LETT 2021. [DOI: 10.1246/cl.200848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hiroyuki Asakura
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Tsunehiro Tanaka
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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7
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Goodwin CAP, Réant BLL, Kragskow JGC, DiMucci IM, Lancaster KM, Mills DP, Sproules S. Heteroleptic samarium(iii) halide complexes probed by fluorescence-detected L 3-edge X-ray absorption spectroscopy. Dalton Trans 2018; 47:10613-10625. [PMID: 29790545 PMCID: PMC6083822 DOI: 10.1039/c8dt01452c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The novel series of heteroleptic Sm(iii) halide complexes provides the backdrop for a fluorescence-detected Lα1 X-ray absorption spectroscopic study.
The addition of various oxidants to the near-linear Sm(ii) complex [Sm(N††)2] (1), where N†† is the bulky bis(triisopropylsilyl)amide ligand {N(SiiPr3)2}, afforded a family of heteroleptic three-coordinate Sm(iii) halide complexes, [Sm(N††)2(X)] (X = F, 2-F; Cl, 2-Cl; Br, 2-Br; I, 2-I). In addition, the trinuclear cluster [{Sm(N††)}3(μ2-I)3(μ3-I)2] (3), which formally contains one Sm(ii) and two Sm(iii) centres, was isolated during the synthesis of 2-I. Complexes 2-X are remarkably stable towards ligand redistribution, which is often a facile process for heteroleptic complexes of smaller monodentate ligands in lanthanide chemistry, including the related bis(trimethylsilyl)amide {N(SiMe3)2} (N′′). Complexes 2-X and 3 have been characterised by single crystal X-ray diffraction, elemental analysis, multinuclear NMR, FTIR and electronic spectroscopy. The Lα1 fluorescence-detected X-ray absorption spectra recorded at the Sm L3-edge for 2-X exhibited a resolved pre-edge peak defined as an envelope of quadrupole-allowed 2p → 4f transitions. The X-ray absorption spectral features were successfully reproduced using time-dependent density functional theoretical (TD-DFT) calculations that synergistically support the experimental observations as well as the theoretical model upon which the electronic structure and bonding in these lanthanide complexes is derived.
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Affiliation(s)
- Conrad A P Goodwin
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Benjamin L L Réant
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Jon G C Kragskow
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Ida M DiMucci
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York, 14853, USA.
| | - Kyle M Lancaster
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York, 14853, USA.
| | - David P Mills
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Stephen Sproules
- WestCHEM, School of Chemistry, The University of Glasgow, Glasgow G12 8QQ, UK.
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8
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Zimmer P, Burkhardt L, Friedrich A, Steube J, Neuba A, Schepper R, Müller P, Flörke U, Huber M, Lochbrunner S, Bauer M. The Connection between NHC Ligand Count and Photophysical Properties in Fe(II) Photosensitizers: An Experimental Study. Inorg Chem 2017; 57:360-373. [DOI: 10.1021/acs.inorgchem.7b02624] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Peter Zimmer
- Department
Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Lukas Burkhardt
- Department
Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Aleksej Friedrich
- Institute
of Physics, University of Rostock, Albert-Einstein-Str. 23, 18059 Rostock, Germany
| | - Jakob Steube
- Department
Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Adam Neuba
- Department
Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Rahel Schepper
- Department
Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Patrick Müller
- Department
Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Ulrich Flörke
- Department
Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Marina Huber
- Department
Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Stefan Lochbrunner
- Institute
of Physics, University of Rostock, Albert-Einstein-Str. 23, 18059 Rostock, Germany
| | - Matthias Bauer
- Department
Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
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9
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Burkhardt L, Holzwarth M, Plietker B, Bauer M. Detection and Characterization of Hydride Ligands in Iron Complexes by High-Resolution Hard X-ray Spectroscopy and Implications for Catalytic Processes. Inorg Chem 2017; 56:13300-13310. [PMID: 29058447 DOI: 10.1021/acs.inorgchem.7b02063] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Two hydride catalysts [Fe(CO)(dppp)H(NO)] (dppp = 1,3-bis(diphenylphosphino)propane) and [Fe(CO)H(NO)(PPh3)2] in comparison with nonhydride analogues [Fe(dppe)(NO)2] (dppe = 1,3-bis(diphenylphosphino)ethane) and [Fe(NO)2(PPh3)2] are investigated with a combination of valence-to-core X-ray emission spectroscopy (VtC-XES) and high-energy resolution fluorescence detected X-ray absorption near-edge structure (HERFD-XANES). To fully understand the experiments and to obtain precise information about molecular levels being involved in the spectral signals, time-dependent density functional theory (TD-DFT) calculations and ground state density functional theory (DFT) calculations are necessary. An excellent agreement between experiment and theory allows the identification of particular spectral signals of the Fe-H group. Antibonding Fe-H interactions clearly contribute to pre-edge signals in HERFD-XANES spectra, while bonding Fe-H interactions cause characteristic signatures in the VtC-XES spectra. The sensitivity of both methods with respect to the Fe-H distance is demonstrated by a scanning simulation approach. The results open the way to study metal hydride complexes in situ, their formation, and their fate during catalytic reactions, using high-resolution XANES and valence-to-core X-ray emission spectroscopy.
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Affiliation(s)
- Lukas Burkhardt
- Department Chemie, Universität Paderborn , Warburger Straße 100, D-33098 Paderborn, Germany
| | - Michael Holzwarth
- Institut für Organische Chemie, Universität Stuttgart , Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Bernd Plietker
- Institut für Organische Chemie, Universität Stuttgart , Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Matthias Bauer
- Department Chemie, Universität Paderborn , Warburger Straße 100, D-33098 Paderborn, Germany
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10
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Hettiarachchi GM, Donner E, Doelsch E. Application of Synchrotron Radiation-based Methods for Environmental Biogeochemistry: Introduction to the Special Section. JOURNAL OF ENVIRONMENTAL QUALITY 2017; 46:1139-1145. [PMID: 29293855 DOI: 10.2134/jeq2017.09.0349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
To understand the biogeochemistry of nutrients and contaminants in environmental media, their speciation and behavior under different conditions and at multiple scales must be determined. Synchrotron radiation-based X-ray techniques allow scientists to elucidate the underlying mechanisms responsible for nutrient and contaminant mobility, bioavailability, and behavior. The continuous improvement of synchrotron light sources and X-ray beamlines around the world has led to a profound transformation in the field of environmental biogeochemistry and, subsequently, to significant scientific breakthroughs. Following this introductory paper, this special collection includes 10 papers that either present targeted reviews of recent advancements in spectroscopic methods that are applicable to environmental biogeochemistry or describe original research studies conducted on complex environmental samples that have been significantly enhanced by incorporating synchrotron radiation-based X-ray technique(s). We believe that the current focus on improving the speciation of ultra-dilute elements in environmental media through the ongoing optimization of synchrotron technologies (e.g., brighter light sources, improved monochromators, more efficient detectors) will help to significantly push back the frontiers of environmental biogeochemistry research. As many of the relevant techniques produce extremely large datasets, we also identify ongoing improvements in data processing and analysis (e.g., software improvements and harmonization of analytical methods) as a significant requirement for environmental biogeochemists to maximize the information that can be gained using these powerful tools.
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11
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Proux O, Lahera E, Del Net W, Kieffer I, Rovezzi M, Testemale D, Irar M, Thomas S, Aguilar-Tapia A, Bazarkina EF, Prat A, Tella M, Auffan M, Rose J, Hazemann JL. High-Energy Resolution Fluorescence Detected X-Ray Absorption Spectroscopy: A Powerful New Structural Tool in Environmental Biogeochemistry Sciences. JOURNAL OF ENVIRONMENTAL QUALITY 2017; 46:1146-1157. [PMID: 29293835 DOI: 10.2134/jeq2017.01.0023] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The study of the speciation of highly diluted elements by X-ray absorption spectroscopy (XAS) is extremely challenging, especially in environmental biogeochemistry sciences. Here we present an innovative synchrotron spectroscopy technique: high-energy resolution fluorescence detected XAS (HERFD-XAS). With this approach, measurement of the XAS signal in fluorescence mode using a crystal analyzer spectrometer with a ∼1-eV energy resolution helps to overcome restrictions on sample concentrations that can be typically measured with a solid-state detector. We briefly describe the method, from both an instrumental and spectroscopic point of view, and emphasize the effects of energy resolution on the XAS measurements. We then illustrate the positive impact of this technique in terms of detection limit with two examples dealing with Ce in ecologically relevant organisms and with Hg species in natural environments. The sharp and well-marked features of the HERFD-X-ray absorption near-edge structure spectra obtained enable us to determine unambiguously and with greater precision the speciation of the probed elements. This is a major technological advance, with strong benefits for the study of highly diluted elements using XAS. It also opens new possibilities to explore the speciation of a target chemical element at natural concentration levels, which is critical in the fields of environmental and biogeochemistry sciences.
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12
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Santomauro FG, Grilj J, Mewes L, Nedelcu G, Yakunin S, Rossi T, Capano G, Al Haddad A, Budarz J, Kinschel D, Ferreira DS, Rossi G, Gutierrez Tovar M, Grolimund D, Samson V, Nachtegaal M, Smolentsev G, Kovalenko MV, Chergui M. Localized holes and delocalized electrons in photoexcited inorganic perovskites: Watching each atomic actor by picosecond X-ray absorption spectroscopy. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:044002. [PMID: 28083541 PMCID: PMC5178717 DOI: 10.1063/1.4971999] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/11/2016] [Indexed: 05/07/2023]
Abstract
We report on an element-selective study of the fate of charge carriers in photoexcited inorganic CsPbBr3 and CsPb(ClBr)3 perovskite nanocrystals in toluene solutions using time-resolved X-ray absorption spectroscopy with 80 ps time resolution. Probing the Br K-edge, the Pb L3-edge, and the Cs L2-edge, we find that holes in the valence band are localized at Br atoms, forming small polarons, while electrons appear as delocalized in the conduction band. No signature of either electronic or structural changes is observed at the Cs L2-edge. The results at the Br and Pb edges suggest the existence of a weakly localized exciton, while the absence of signatures at the Cs edge indicates that the Cs+ cation plays no role in the charge transport, at least beyond 80 ps. This first, time-resolved element-specific study of perovskites helps understand the rather modest charge carrier mobilities in these materials.
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Affiliation(s)
- Fabio G Santomauro
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - Jakob Grilj
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - Lars Mewes
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | | | | | - Thomas Rossi
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - Gloria Capano
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - André Al Haddad
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - James Budarz
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - Dominik Kinschel
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | | | - Giacomo Rossi
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - Mario Gutierrez Tovar
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | | | | | | | | | | | - Majed Chergui
- Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
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13
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Zheng K, Abdellah M, Zhu Q, Kong Q, Jennings G, Kurtz CA, Messing ME, Niu Y, Gosztola DJ, Al-Marri MJ, Zhang X, Pullerits T, Canton SE. Direct Experimental Evidence for Photoinduced Strong-Coupling Polarons in Organolead Halide Perovskite Nanoparticles. J Phys Chem Lett 2016; 7:4535-4539. [PMID: 27790918 DOI: 10.1021/acs.jpclett.6b02046] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Echoing the roaring success of their bulk counterparts, nano-objects built from organolead halide perovskites (OLHP) present bright prospects for surpassing the performances of their conventional organic and inorganic analogues in photodriven technologies. Unraveling the photoinduced charge dynamics is essential for optimizing the optoelectronic functionalities. However, mapping the carrier-lattice interactions remains challenging, owing to their manifestations on multiple length scales and time scales. By correlating ultrafast time-resolved optical and X-ray absorption measurements, this work reveals the photoinduced formation of strong-coupling polarons in CH3NH3PbBr3 nanoparticles. Such polarons originate from the self-trapping of electrons in the Coulombic field caused by the displaced inorganic nuclei and the oriented organic cations. The transient structural change detected at the Pb L3 X-ray absorption edge is well-captured by a distortion with average bond elongation in the [PbBr6]2- motif. General implications for designing novel OLHP nanomaterials targeting the active utilization of these quasi-particles are outlined.
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Affiliation(s)
- Kaibo Zheng
- Department of Chemical Physics and Nanolund, Lund University , Box 124, 22100 Lund, Sweden
- Gas Processing Center, College of Engineering, Qatar University , PO Box 2713, Doha, Qatar
| | - Mohamed Abdellah
- Department of Chemical Physics and Nanolund, Lund University , Box 124, 22100 Lund, Sweden
- Department of Chemistry, Qena Faculty of Science, South Valley University , Qena 83523, Egypt
| | - Qiushi Zhu
- Department of Chemical Physics and Nanolund, Lund University , Box 124, 22100 Lund, Sweden
- Gas Processing Center, College of Engineering, Qatar University , PO Box 2713, Doha, Qatar
| | - Qingyu Kong
- X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Guy Jennings
- X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Charles A Kurtz
- X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Maria E Messing
- Department of Solid State Physics and Nanolund, Lund University , Box 118, 22100 Lund, Sweden
| | - Yuran Niu
- MAX IV Laboratory, Lund University , Box 118, 22100 Lund, Sweden
| | - David J Gosztola
- X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Mohammed J Al-Marri
- Gas Processing Center, College of Engineering, Qatar University , PO Box 2713, Doha, Qatar
| | - Xiaoyi Zhang
- X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Tönu Pullerits
- Department of Chemical Physics and Nanolund, Lund University , Box 124, 22100 Lund, Sweden
| | - Sophie E Canton
- Center for Ultrafast Imaging, University of Hamburg , 22761 Hamburg, Germany
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Jin R, Jiang X, Zhou Y, Zhao J. Microspheres of graphene oxide coupled to N-doped Bi2O2CO3 for visible light photocatalysis. CHINESE JOURNAL OF CATALYSIS 2016. [DOI: 10.1016/s1872-2067(15)61079-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Stewart TJ, Szlachetko J, Sigg L, Behra R, Nachtegaal M. Tracking the Temporal Dynamics of Intracellular Lead Speciation in a Green Alga. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:11176-81. [PMID: 26320742 DOI: 10.1021/acs.est.5b02603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Organisms have developed metal regulatory mechanisms in response to changes in the bioavailability of trace metals. Just as metal bioavailability dictates cellular uptake, intracellular metal speciation determines the availability of metals to exert biological effects. However, the missing link in understanding the relationship between metal uptake and biological responses is the ability to accurately measure intracellular metal speciation. We conducted Pb exposure studies on the well-characterized model green alga Chlamydomonas reinhardtii and identified temporal changes in intracellular Pb speciation under conditions relevant for fresh water ecosystems using resonant X-ray emission spectroscopy (RXES), which possesses enhanced sensitivity to functional group chemistry relative to X-ray absorption spectroscopy (XAS). Analysis of RXES maps show that only a small fraction of total intracellular Pb was complexed by thiol groups. Initial sequestration of Pb in oxides and inorganic phosphate was followed by binding of Pb to organic phosphate, suggesting potential interference in vital cellular functions. These results contrast proposed detoxification responses involving complexation by thiol groups from peptides.
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Affiliation(s)
- T J Stewart
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- ETH , Institute of Biogeochemistry and Pollutant Dynamics IBP, CH-8092 Zurich, Switzerland
| | - J Szlachetko
- Paul Scherrer Institute , 5232 Villigen PSI, Switzerland
- Institute of Physics, Jan Kochanowski University , P-25-406 Kielce, Poland
| | - L Sigg
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- ETH , Institute of Biogeochemistry and Pollutant Dynamics IBP, CH-8092 Zurich, Switzerland
| | - R Behra
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
| | - M Nachtegaal
- Paul Scherrer Institute , 5232 Villigen PSI, Switzerland
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16
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Zheng K, Zhu Q, Abdellah M, Messing ME, Zhang W, Generalov A, Niu Y, Ribaud L, Canton SE, Pullerits T. Exciton Binding Energy and the Nature of Emissive States in Organometal Halide Perovskites. J Phys Chem Lett 2015; 6:2969-75. [PMID: 26267190 DOI: 10.1021/acs.jpclett.5b01252] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Characteristics of nanoscale materials are often different from the corresponding bulk properties providing new, sometimes unexpected, opportunities for applications. Here we investigate the properties of 8 nm colloidal nanoparticles of MAPbBr3 perovskites and contrast them to the ones of large microcrystallites representing a bulk. X-ray spectroscopies provide an exciton binding energy of 0.32 ± 0.10 eV in the nanoparticles. This is 5 times higher than the value of bulk crystals (0.084 ± 0.010 eV), and readily explains the high fluorescence quantum yield in nanoparticles. In the bulk, at high excitation concentrations, the fluorescence intensity has quadratic behavior following the Saha-Langmuir model due to the nongeminate recombination of charges forming the emissive exciton states. In the nanoparticles, a linear dependence is observed since the excitation concentration per particle is significantly less than one. Even the bulk shows linear emission intensity dependence at lower excitation concentrations. In this case, the average excitation spacing becomes larger than the carrier diffusion length suppressing the nongeminate recombination. From these considerations we obtain the charge carrier diffusion length in MAPbBr3 of 100 nm.
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Affiliation(s)
- Kaibo Zheng
- †Department of Chemical Physics, Lund University, Box 124, 22100, Lund, Sweden
| | - Qiushi Zhu
- §Department of Synchrotron Radiation Instrumentation, Lund University, Box 118, 22100, Lund, Sweden
| | - Mohamed Abdellah
- †Department of Chemical Physics, Lund University, Box 124, 22100, Lund, Sweden
- ‡Department of Chemistry, Qena Faculty of Science, South Valley University, Qena 83523, Egypt
| | - Maria E Messing
- ∥Deptartment of Solid State Physics, Lund University, Box 118, 22100, Lund, Sweden
| | - Wei Zhang
- †Department of Chemical Physics, Lund University, Box 124, 22100, Lund, Sweden
| | | | - Yuran Niu
- ⊥MAX IV Laboratory, Lund University, Box 118, 22100, Lund, Sweden
| | - Lynn Ribaud
- #X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Sophie E Canton
- ∇IFG Structural Dynamics of (Bio)chemical Systems, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Goettingen, Germany
- ○FS-SCS, Structural Dynamics with Ultra-short Pulsed X-rays, Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg, Germany
| | - Tõnu Pullerits
- †Department of Chemical Physics, Lund University, Box 124, 22100, Lund, Sweden
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17
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Jalilehvand F, Sisombath NS, Schell AC, Facey GA. Lead(II) complex formation with L-cysteine in aqueous solution. Inorg Chem 2015; 54:2160-70. [PMID: 25695880 DOI: 10.1021/ic5025668] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The lead(II) complexes formed with the multidentate chelator L-cysteine (H2Cys) in an alkaline aqueous solution were studied using (207)Pb, (13)C, and (1)H NMR, Pb LIII-edge X-ray absorption, and UV-vis spectroscopic techniques, complemented by electrospray ion mass spectrometry (ESI-MS). The H2Cys/Pb(II) mole ratios were varied from 2.1 to 10.0 for two sets of solutions with CPb(II) = 0.01 and 0.1 M, respectively, prepared at pH values (9.1-10.4) for which precipitates of lead(II) cysteine dissolved. At low H2Cys/Pb(II) mole ratios (2.1-3.0), a mixture of the dithiolate [Pb(S,N-Cys)2](2-) and [Pb(S,N,O-Cys)(S-HCys)](-) complexes with average Pb-(N/O) and Pb-S distances of 2.42 ± 0.04 and 2.64 ± 0.04 Å, respectively, was found to dominate. At high concentration of free cysteinate (>0.7 M), a significant amount converts to the trithiolate [Pb(S,N-Cys)(S-HCys)2](2-), including a minor amount of a PbS3-coordinated [Pb(S-HCys)3](-) complex. The coordination mode was evaluated by fitting linear combinations of EXAFS oscillations to the experimental spectra and by examining the (207)Pb NMR signals in the chemical shift range δPb = 2006-2507 ppm, which became increasingly deshielded with increasing free cysteinate concentration. One-pulse magic-angle-spinning (MAS) (207)Pb NMR spectra of crystalline Pb(aet)2 (Haet = 2-aminoethanethiol or cysteamine) with PbS2N2 coordination were measured for comparison (δiso = 2105 ppm). The UV-vis spectra displayed absorption maxima at 298-300 nm (S(-) → Pb(II) charge transfer) for the dithiolate PbS2N(N/O) species; with increasing ligand excess, a shoulder appeared at ∼330 nm for the trithiolate PbS3N and PbS3 (minor) complexes. The results provide spectroscopic fingerprints for structural models for lead(II) coordination modes to proteins and enzymes.
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Affiliation(s)
- Farideh Jalilehvand
- Department of Chemistry, University of Calgary , 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
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18
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19
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Jayarathne U, Chandrasekaran P, Greene A, Mague JT, DeBeer S, Lancaster KM, Sproules S, Donahue JP. X-ray absorption spectroscopy systematics at the tungsten L-edge. Inorg Chem 2014; 53:8230-41. [PMID: 25068843 PMCID: PMC4139175 DOI: 10.1021/ic500256a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Indexed: 01/08/2023]
Abstract
A series of mononuclear six-coordinate tungsten compounds spanning formal oxidation states from 0 to +VI, largely in a ligand environment of inert chloride and/or phosphine, was interrogated by tungsten L-edge X-ray absorption spectroscopy. The L-edge spectra of this compound set, comprised of [W(0)(PMe3)6], [W(II)Cl2(PMePh2)4], [W(III)Cl2(dppe)2][PF6] (dppe = 1,2-bis(diphenylphosphino)ethane), [W(IV)Cl4(PMePh2)2], [W(V)(NPh)Cl3(PMe3)2], and [W(VI)Cl6], correlate with formal oxidation state and have usefulness as references for the interpretation of the L-edge spectra of tungsten compounds with redox-active ligands and ambiguous electronic structure descriptions. The utility of these spectra arises from the combined correlation of the estimated branching ratio of the L3,2-edges and the L1 rising-edge energy with metal Zeff, thereby permitting an assessment of effective metal oxidation state. An application of these reference spectra is illustrated by their use as backdrop for the L-edge X-ray absorption spectra of [W(IV)(mdt)2(CO)2] and [W(IV)(mdt)2(CN)2](2-) (mdt(2-) = 1,2-dimethylethene-1,2-dithiolate), which shows that both compounds are effectively W(IV) species even though the mdt ligands exist at different redox levels in the two compounds. Use of metal L-edge XAS to assess a compound of uncertain formulation requires: (1) Placement of that data within the context of spectra offered by unambiguous calibrant compounds, preferably with the same coordination number and similar metal ligand distances. Such spectra assist in defining upper and/or lower limits for metal Zeff in the species of interest. (2) Evaluation of that data in conjunction with information from other physical methods, especially ligand K-edge XAS. (3) Increased care in interpretation if strong π-acceptor ligands, particularly CO, or π-donor ligands are present. The electron-withdrawing/donating nature of these ligand types, combined with relatively short metal-ligand distances, exaggerate the difference between formal oxidation state and metal Zeff or, as in the case of [W(IV)(mdt)2(CO)2], exert the subtle effect of modulating the redox level of other ligands in the coordination sphere.
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Affiliation(s)
- Upul Jayarathne
- Department
of Chemistry, Tulane University, 6400 Freret Street, New Orleans, Louisiana 70118, United States
| | - Perumalreddy Chandrasekaran
- Department
of Chemistry, Tulane University, 6400 Freret Street, New Orleans, Louisiana 70118, United States
- Department
of Chemistry and Biochemistry, Lamar University, Beaumont, Texas 77710, United States
| | - Angelique
F. Greene
- Department
of Chemistry, Tulane University, 6400 Freret Street, New Orleans, Louisiana 70118, United States
| | - Joel T. Mague
- Department
of Chemistry, Tulane University, 6400 Freret Street, New Orleans, Louisiana 70118, United States
| | - Serena DeBeer
- Department
of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstrasse 34-36, D-45470, Mülheim an der Ruhr, Germany
| | - Kyle M. Lancaster
- Department
of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
| | - Stephen Sproules
- WestCHEM,
School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - James P. Donahue
- Department
of Chemistry, Tulane University, 6400 Freret Street, New Orleans, Louisiana 70118, United States
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20
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Lima FA, Bjornsson R, Weyhermüller T, Chandrasekaran P, Glatzel P, Neese F, DeBeer S. High-resolution molybdenum K-edge X-ray absorption spectroscopy analyzed with time-dependent density functional theory. Phys Chem Chem Phys 2014; 15:20911-20. [PMID: 24197060 DOI: 10.1039/c3cp53133c] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
X-ray absorption spectroscopy (XAS) is a widely used experimental technique capable of selectively probing the local structure around an absorbing atomic species in molecules and materials. When applied to heavy elements, however, the quantitative interpretation can be challenging due to the intrinsic spectral broadening arising from the decrease in the core-hole lifetime. In this work we have used high-energy resolution fluorescence detected XAS (HERFD-XAS) to investigate a series of molybdenum complexes. The sharper spectral features obtained by HERFD-XAS measurements enable a clear assignment of the features present in the pre-edge region. Time-dependent density functional theory (TDDFT) has been previously shown to predict K-pre-edge XAS spectra of first row transition metal compounds with a reasonable degree of accuracy. Here we extend this approach to molybdenum K-edge HERFD-XAS and present the necessary calibration. Modern pure and hybrid functionals are utilized and relativistic effects are accounted for using either the Zeroth Order Regular Approximation (ZORA) or the second order Douglas-Kroll-Hess (DKH2) scalar relativistic approximations. We have found that both the predicted energies and intensities are in excellent agreement with experiment, independent of the functional used. The model chosen to account for relativistic effects also has little impact on the calculated spectra. This study provides an important calibration set for future applications of molybdenum HERFD-XAS to complex catalytic systems.
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Affiliation(s)
- Frederico A Lima
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D- 45470, Mülheim an der Ruhr, Germany.
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Kvashnina KO, Butorin SM, Martin P, Glatzel P. Chemical state of complex uranium oxides. PHYSICAL REVIEW LETTERS 2013; 111:253002. [PMID: 24483742 DOI: 10.1103/physrevlett.111.253002] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Indexed: 05/15/2023]
Abstract
We report here the first direct observation of U(V) in uranium binary oxides and analyze the gradual conversion of the U oxidation state in the mixed uranium systems. Our finding clarifies previous contradicting results and provides important input for the geological disposal of spent fuel, recycling applications, and chemistry of uranium species.
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Affiliation(s)
- K O Kvashnina
- European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP 220, 38043, Grenoble, France
| | - S M Butorin
- Department of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala, Sweden
| | - P Martin
- CEA, DEN, DEC, CEN Cadarache, 13108, St. Paul lez Durance, France
| | - P Glatzel
- European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP 220, 38043, Grenoble, France
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22
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Lundberg M, Kroll T, DeBeer S, Bergmann U, Wilson SA, Glatzel P, Nordlund D, Hedman B, Hodgson KO, Solomon EI. Metal-ligand covalency of iron complexes from high-resolution resonant inelastic X-ray scattering. J Am Chem Soc 2013; 135:17121-34. [PMID: 24131028 PMCID: PMC3920600 DOI: 10.1021/ja408072q] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Data from Kα resonant inelastic X-ray scattering (RIXS) have been used to extract electronic structure information, i.e., the covalency of metal-ligand bonds, for four iron complexes using an experimentally based theoretical model. Kα RIXS involves resonant 1s→3d excitation and detection of the 2p→1s (Kα) emission. This two-photon process reaches similar final states as single-photon L-edge (2p→3d) X-ray absorption spectroscopy (XAS), but involves only hard X-rays and can therefore be used to get high-resolution L-edge-like spectra for metal proteins, solution catalysts and their intermediates. To analyze the information content of Kα RIXS spectra, data have been collected for four characteristic σ-donor and π-back-donation complexes: ferrous tacn [Fe(II)(tacn)2]Br2, ferrocyanide [Fe(II)(CN)6]K4, ferric tacn [Fe(III)(tacn)2]Br3 and ferricyanide [Fe(III)(CN)6]K3. From these spectra metal-ligand covalencies can be extracted using a charge-transfer multiplet model, without previous information from the L-edge XAS experiment. A direct comparison of L-edge XAS and Kα RIXS spectra show that the latter reaches additional final states, e.g., when exciting into the e(g) (σ*) orbitals, and the splitting between final states of different symmetry provides an extra dimension that makes Kα RIXS a more sensitive probe of σ-bonding. Another key difference between L-edge XAS and Kα RIXS is the π-back-bonding features in ferro- and ferricyanide that are significantly more intense in L-edge XAS compared to Kα RIXS. This shows that two methods are complementary in assigning electronic structure. The Kα RIXS approach can thus be used as a stand-alone method, in combination with L-edge XAS for strongly covalent systems that are difficult to probe by UV/vis spectroscopy, or as an extension to conventional absorption spectroscopy for a wide range of transition metal enzymes and catalysts.
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Affiliation(s)
- Marcus Lundberg
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Thomas Kroll
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Serena DeBeer
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Uwe Bergmann
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Samuel A. Wilson
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | | | - Dennis Nordlund
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Britt Hedman
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Keith O. Hodgson
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
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Bordage A, Pápai M, Sas NS, Szlachetko J, Nachtegaal M, Vankó G. On the sensitivity of hard X-ray spectroscopies to the chemical state of Br. Phys Chem Chem Phys 2013; 15:11088-98. [DOI: 10.1039/c3cp50367d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Gumeniuk R, Kvashnina KO, Schnelle W, Nicklas M, Borrmann H, Rosner H, Skourski Y, Tsirlin AA, Leithe-Jasper A, Grin Y. Physical properties and valence state of cerium in the filled skutterudite CePt₄Ge₁₂. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:465601. [PMID: 22056917 DOI: 10.1088/0953-8984/23/46/465601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Electronic, magnetic, and transport properties of the filled platinum-germanium skutterudite CePt₄Ge₁₂ are investigated. High resolution x-ray absorption spectroscopy measurements at the cerium L(III) edge demonstrate that CePt₄Ge₁₂ in this compound has a temperature-independent valence close to three. However, magnetic susceptibility, thermopower, Hall effect, and electronic specific heat reveal a broad maximum at Tmax D 65-80 K, suggesting the presence of valence fluctuations. The Sommerfeld coefficient γ = 105 mJ mol⁻¹ K⁻², deduced from specific heat, indicates moderately enhanced band masses for CePt₄Ge₁₂. We discuss these findings and conclude that CePt₄Ge₁₂ represents a system at the border between intermediate valence (IV) and Kondo lattice behavior. In addition, the lattice specific heat and the thermal conductivity are discussed with respect to the vibrational dynamics of Ce in the [Pt₄Ge₁₂] framework.
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Affiliation(s)
- R Gumeniuk
- Max-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany
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Link P, Glatzel P, Kvashnina K, Smith RI, Ruschewitz U. Yb Valence States in YbC2: A HERFD-XANES Spectroscopic Investigation. Inorg Chem 2011; 50:5587-95. [PMID: 21612187 DOI: 10.1021/ic200247z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pascal Link
- Department of Chemistry, University of Cologne, Greinstrasse 6, D-50939 Cologne, Germany
| | - Pieter Glatzel
- European Synchrotron Radiation Facility, BP 220, 6 rue Horowitz, F-38043 Grenoble, France
| | - Kristina Kvashnina
- European Synchrotron Radiation Facility, BP 220, 6 rue Horowitz, F-38043 Grenoble, France
| | - Ronald I. Smith
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K
| | - Uwe Ruschewitz
- Department of Chemistry, University of Cologne, Greinstrasse 6, D-50939 Cologne, Germany
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26
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Swarbrick JC, Weng TC, Schulte K, Khlobystov AN, Glatzel P. Electronic structure changes in cobalt phthalocyanine due to nanotube encapsulation probed using resonant inelastic X-ray scattering. Phys Chem Chem Phys 2010; 12:9693-9. [DOI: 10.1039/c002501a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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