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Martini A, Bugaev AL, Guda SA, Guda AA, Priola E, Borfecchia E, Smolders S, Janssens K, De Vos D, Soldatov AV. Revisiting the Extended X-ray Absorption Fine Structure Fitting Procedure through a Machine Learning-Based Approach. J Phys Chem A 2021; 125:7080-7091. [PMID: 34351779 DOI: 10.1021/acs.jpca.1c03746] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel approach for the analysis of extended X-ray absorption fine structure (EXAFS) spectra is developed exploiting an inverse machine learning-based algorithm. Through this approach, it is possible to explore and account for, in a precise way, the nonlinear geometry dependence of the photoelectron backscattering phases and amplitudes of single and multiple scattering paths. In addition, the determined parameters are directly related to the 3D atomic structure, without the need to use complex parametrization as in the classical fitting approach. The applicability of the approach, its potential and the advantages over the classical fit were demonstrated by fitting the EXAFS data of two molecular systems, namely, the KAu (CN)2 and the [RuCl2(CO)3]2 complexes.
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Affiliation(s)
- A Martini
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russia.,Department of Chemistry, University of Torino, Via P. Giuria 7, 10125 Torino, Italy
| | - A L Bugaev
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russia.,Southern Scientific Centre, Russian Academy of Sciences, Chekhova 41, 344006 Rostov-on-Don, Russia
| | - S A Guda
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russia.,Institute of mathematics, mechanics and computer science, Southern Federal University, Milchakova 8a, 344090 Rostov-on-Don, Russia
| | - A A Guda
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russia
| | - E Priola
- Department of Chemistry, University of Torino, Via P. Giuria 7, 10125 Torino, Italy.,CrisDi, Interdepartemental Center for Crystallography, University of Turin, Torino, Via P. Giuria 7, I-10125 Italy
| | - E Borfecchia
- Department of Chemistry, University of Torino, Via P. Giuria 7, 10125 Torino, Italy
| | - S Smolders
- Department of Microbial and Molecular Systems (M2S); Centre for Membrane separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F, Post box 2454, 3001 Leuven, Belgium
| | - K Janssens
- Department of Microbial and Molecular Systems (M2S); Centre for Membrane separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F, Post box 2454, 3001 Leuven, Belgium
| | - D De Vos
- Department of Microbial and Molecular Systems (M2S); Centre for Membrane separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F, Post box 2454, 3001 Leuven, Belgium
| | - A V Soldatov
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090 Rostov-on-Don, Russia
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2
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Lee E, Muhammad S, Kim T, Kim H, Lee W, Yoon W. Tracking the Influence of Thermal Expansion and Oxygen Vacancies on the Thermal Stability of Ni-Rich Layered Cathode Materials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1902413. [PMID: 32596103 PMCID: PMC7312338 DOI: 10.1002/advs.201902413] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 02/23/2020] [Indexed: 05/28/2023]
Abstract
The ever-growing demand for high-energy lithium-ion batteries in portable electronics and electric vehicles has triggered intensive research efforts over the past decade. An efficient strategy to boost the energy and power density of lithium-ion batteries is to increase the Ni content in the cathode materials. However, a higher Ni content in the cathode materials gives rise to safety issues. Herein, thermal expansion and oxygen vacancies are proposed as new critical factors that affect the thermal stability of charged Ni-rich cathode materials based on a systematic synchrotron-based X-ray study of Li0.33Ni0.5+ x Co0.2Mn0.3- x O2 (x = 0, 0.1, 0.2) cathode materials during a heating process. Charged cathode materials with higher Ni contents show larger thermal expansion, which accelerates transition metal migration to the Li layers. Oxygen vacancies are formed and accumulate mainly around Ni ions until the layered-to-spinel phase transition begins. The oxygen vacancies also facilitate transition metal migration to the Li layers. Thermal expansion and the presence of oxygen vacancies decrease the energy barrier for cation migration and facilitate the phase transitions in charged cathode materials during the heating process. These results provide valuable guidance for developing new cathode materials with improved safety characteristics.
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Affiliation(s)
- Eunkang Lee
- Department of Energy ScienceSungkyunkwan UniversitySuwon440‐746South Korea
| | - Shoaib Muhammad
- Department of Energy ScienceSungkyunkwan UniversitySuwon440‐746South Korea
- Present address:
Department of Chemistry and Chemical EngineeringSyed Babar Ali School of Science and Engineering (SBASSE)Lahore University of Management Sciences (LUMS)Lahore54792Pakistan
| | - Taewhan Kim
- Department of Energy ScienceSungkyunkwan UniversitySuwon440‐746South Korea
| | - Hyunchul Kim
- Materials Sciences DivisionLawrence Berkeley National LaboratoryBerkeleyCA94720USA
| | - Wontae Lee
- Department of Energy ScienceSungkyunkwan UniversitySuwon440‐746South Korea
| | - Won‐Sub Yoon
- Department of Energy ScienceSungkyunkwan UniversitySuwon440‐746South Korea
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3
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Hosseiniamoli H, Setiawan A, Adesina AA, Kennedy EM, Stockenhuber M. The stability of Pd/TS-1 and Pd/silicalite-1 for catalytic oxidation of methane – understanding the role of titanium. Catal Sci Technol 2020. [DOI: 10.1039/c9cy01579e] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The stability of Pd/TS-1 and Pd/silicalite-1 catalysts was assessed at 400 °C and an approximate relative humidity (RH) of 80% for catalytic combustion of fugitive methane emissions, aiming to understand the role of titanium in the stability of the catalysts.
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Affiliation(s)
- Hadi Hosseiniamoli
- Center for Infrastructure Engineering
- Western Sydney University
- Sydney
- Australia
| | - Adi Setiawan
- Mechanical Engineering Department
- Universitas Malikussaleh
- Lhokseumawe
- Indonesia
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4
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Hosseiniamoli H, Bryant G, Kennedy EM, Mathisen K, Nicholson D, Sankar G, Setiawan A, Stockenhuber M. Understanding Structure–Function Relationships in Zeolite-Supported Pd Catalysts for Oxidation of Ventilation Air Methane. ACS Catal 2018. [DOI: 10.1021/acscatal.7b04462] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Glenn Bryant
- The University of Newcastle, Newcastle 2308, Australia
| | | | - Karina Mathisen
- Norwegian University of Science & Technology, Trondheim N-7491, Norway
| | - David Nicholson
- Norwegian University of Science & Technology, Trondheim N-7491, Norway
| | - Gopinathan Sankar
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Adi Setiawan
- Mechanical Engineering Department, Universitas Malikussaleh, Lhokseumawe 24352, Indonesia
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5
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Sestu M, Navarra G, Carrero S, Valvidares SM, Aquilanti G, Pérez-Lopez R, Fernandez-Martinez A. Whole-nanoparticle atomistic modeling of the schwertmannite structure from total scattering data. J Appl Crystallogr 2017. [DOI: 10.1107/s160057671701336x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Schwertmannite is a poorly crystalline nanometric iron sulfate oxyhydroxide. This mineral shows a structural variability under different environments. Because of that, the determination of its structure and, consequently, of its physical–chemical properties is quite challenging. This article presents a detailed structural investigation of the structure of schwertmannite conducted under different approaches: X-ray absorption spectroscopy, Rietveld refinement, and a combined reverse Monte Carlo and Debye function analysis of the whole nanoparticle structure. The schwertmannite model presented here is, to the auhors' knowledge, the most complete model so far reported.
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6
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Carrero S, Fernandez-Martinez A, Pérez-López R, Poulain A, Salas-Colera E, Nieto JM. Arsenate and Selenate Scavenging by Basaluminite: Insights into the Reactivity of Aluminum Phases in Acid Mine Drainage. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:28-37. [PMID: 27995804 DOI: 10.1021/acs.est.6b03315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Basaluminite precipitation may play an important role in the behavior of trace elements in water and sediments affected by acid mine drainage and acid sulfate soils. In this study, the affinity of basaluminite and schwertmannite for arsenate and selenate is compared, and the coordination geometries of these oxyanions in both structures are reported. Batch isotherm experiments were conducted to examine the sorption capacity of synthetic schwertmannite and basaluminite and the potential competitive effect of sulfate. In addition, synchrotron-based techniques such as differential pair distribution function (d-PDF) analysis and extended X-ray absorption fine structure (EXAFS) were used to determine the local structure of As(V) and Se(VI) complexes. The results show that oxyanion exchange with structural sulfate was the main mechanism for removal of selenate, whereas arsenate was removed by a combination of surface complexes and oxyanion exchange. The arsenate adsorption capacity of basaluminite was 2 times higher than that of schwertmannite and 3 times higher than that of selenate in both phases. The sulfate:arsenate and sulfate:selenate exchange ratios were 1:2 and 1:1, respectively. High sulfate concentrations in the solutions did not show a competitive effect on arsenate sorption capacity but had a strong impact on selenate uptake, suggesting some kind of specific interaction for arsenate. Both d-PDF and EXAFS results indicated that the bidentate binuclear inner sphere was the most probable type of ligand for arsenate on both phases and for selenate on schwertmannite, whereas selenate forms outer-sphere complexes in the aluminum octahedral interlayer of basaluminite. Overall, these results show a strong affinity of poorly crystalline aluminum phases such as basaluminite for As(V) and Se(VI) oxyanions, with adsorption capacities on the same order of magnitude as those of iron oxides. The results obtained in this study are relevant to the understanding of trace element behavior in environments affected by acid water, potentially opening new research lines focused on remediation by natural attenuation processes or engineered water treatment systems.
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Affiliation(s)
- Sergio Carrero
- Department of Geology, University of Huelva , Campus "El Carmen", 21071 Huelva, Spain
| | | | - Rafael Pérez-López
- Department of Geology, University of Huelva , Campus "El Carmen", 21071 Huelva, Spain
| | | | - Eduardo Salas-Colera
- SpLine Spanish CRG Beamline, ESRF , 6 Rue Jules Horowitz, BP 220 Grenoble Cedex 09, France
- Instituto de Ciencia de Materiales de Madrid, CSIC , Sor Juana Inés de la Cruz 3, Cantoblanco, 28049 Madrid, Spain
| | - José Miguel Nieto
- Department of Geology, University of Huelva , Campus "El Carmen", 21071 Huelva, Spain
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7
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Hacisalihoglu MY, Paris E, Joseph B, Yanmaz E, Saini NL. The nanoscale structure and unoccupied valence electronic states in FeSe1-xTex chalcogenides probed by X-ray absorption measurements. Phys Chem Chem Phys 2015; 17:18131-7. [PMID: 26099493 DOI: 10.1039/c5cp01740h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have studied the nanoscale structure and unoccupied electronic states in FeSe1-xTex by a combined analysis of Se K, Te L1 and Fe K-edges X-ray absorption measurements. Extended X-ray absorption fine structure (EXAFS) results show that iron-chalcogen (Fe-Se and Fe-Te) distances in ternary FeSe1-xTex are similar to those measured for binary FeSe and FeTe. The local Fe-Se/Te distances determined by different absorption edges fit well in the characteristic Z-plot of random alloys, providing unambiguous support to the inhomogeneous nanoscale structure of the ternary FeSe1-xTex system. X-ray absorption near-edge structure (XANES) spectra reveal a gradual evolution of the unoccupied valence electronic states as a function of Te-substitution in FeSe1-xTex. The Fe 3d-Se 4p/Te 5p hybridization is found to decrease with Te-substitution, accompanied by an increase in unoccupied Se 4p states and a decrease in unoccupied Te 5p states. The results are discussed in the frame of local inhomogeneity in the FeSe1-xTex system driven by random alloying of Se/Te atoms.
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Affiliation(s)
- M Y Hacisalihoglu
- Dipartimento di Fisica, Universitá di Roma "La Sapienza", P. le Aldo Moro 2, 00185 Rome, Italy.
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8
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Giles LJ, Ruppelt C, Yang J, Mendel RR, Bittner F, Kirk ML. Molybdenum site structure of MOSC family proteins. Inorg Chem 2014; 53:9460-2. [PMID: 25166909 PMCID: PMC4164224 DOI: 10.1021/ic5015863] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mo K-edge X-ray absorption spectroscopy has been used to probe as-isolated structures of the MOSC family proteins pmARC-1 and HMCS-CT. The Mo K-edge near-edge spectrum of HMCS-CT is shifted ~2.5 eV to lower energy compared to the pmARC-1 spectrum, which indicates that as-isolated HMCS-CT is in a more reduced state than pmARC-1. Extended X-ray absorption fine structure analysis indicates significant structural differences between pmARC-1 and HMCS-CT, with the former being a dioxo site and the latter possessing only a single terminal oxo ligand. The number of terminal oxo donors is consistent with pmARC-1 being in the Mo(VI) oxidation state and HMCS-CT in the Mo(IV) state. These structures are in accord with oxygen-atom-transfer reactivity for pmARC-1 and persulfide bond cleavage chemistry for HMCS-CT.
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Affiliation(s)
- Logan J Giles
- Department of Chemistry and Chemical Biology, The University of New Mexico , MSC03 2060, 1 University of New Mexico, Albuquerque, New Mexico 87131-0001, United States
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9
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Keiber T, Bridges F, Sales BC. Lead is not off center in PbTe: the importance of r-space phase information in extended x-ray absorption fine structure spectroscopy. PHYSICAL REVIEW LETTERS 2013; 111:095504. [PMID: 24033047 DOI: 10.1103/physrevlett.111.095504] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Indexed: 06/02/2023]
Abstract
PbTe is a well-known thermoelectric material. Recent x-ray total scattering studies suggest that Pb moves off center along 100 in PbTe, by ∼0.2 Å at 300 K, producing a split Pb-Te pair distribution. We present an extended x-ray absorption fine structure spectroscopy (EXAFS) study of PbTe (and Tl doped PbTe) to determine if Pb or Te is off center. EXAFS provides sensitive r- or k-space phase information which can differentiate between a split peak for the Pb-Te distribution (indicative of off-center Pb) and a thermally broadened peak. We find no evidence for a split peak for Pb-Te or Te-Pb. At 300 K, the vibration amplitude for Pb-Te (or Te-Pb) is large; this thermally induced disorder is indicative of weak bonds, and the large disorder is consistent with the low thermal conductivity at 300 K. We also find evidence of an anharmonic potential for the nearest Pb-Te bonds, consistent with the overall anharmonicity found for the phonon modes. This effect is modeled by a "skew" factor (C3) which significantly improves the fit of the Pb-Te and Te-Pb peaks for the high temperature EXAFS data; C3 becomes significant above approximately 150-200 K. The consequences of these results will be discussed.
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Affiliation(s)
- T Keiber
- Physics Department, University of California, Santa Cruz, California 95064, USA
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10
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Frankær CG, Knudsen MV, Norén K, Nazarenko E, Ståhl K, Harris P. The structures of T6, T3R3and R6bovine insulin: combining X-ray diffraction and absorption spectroscopy. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:1259-71. [DOI: 10.1107/s090744491202625x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 06/10/2012] [Indexed: 11/11/2022]
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11
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Walczak MS, Lawniczak-Jablonska K, Wolska A, Sikora M, Sienkiewicz A, Suárez L, Kosar AJ, Bellemare MJ, Bohle DS. Toward Understanding the Chloroquine Action at the Molecular Level in Antimalarial Therapy − X-ray Absorption Studies in Acetic Acid Solution. J Phys Chem B 2011; 115:4419-26. [DOI: 10.1021/jp106790r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Monika S. Walczak
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02-668 Warsaw, Poland
| | | | - Anna Wolska
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02-668 Warsaw, Poland
| | - Marcin Sikora
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Al. Mickiewicza 30, PL-30-059 Krakow, Poland
| | - Andrzej Sienkiewicz
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02-668 Warsaw, Poland
- Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - Liliana Suárez
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 2K6, Canada
| | - Aaron J. Kosar
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 2K6, Canada
| | - Marie-Josee Bellemare
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 2K6, Canada
| | - D. Scott Bohle
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 2K6, Canada
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12
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Pushie MJ, Doonan CJ, Moquin K, Weiner JH, Rothery R, George GN. Molybdenum Site Structure of Escherichia coli YedY, a Novel Bacterial Oxidoreductase. Inorg Chem 2010; 50:732-40. [DOI: 10.1021/ic101280m] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. Jake Pushie
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Christian J. Doonan
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Kamila Moquin
- School of Molecular and Systems Medicine, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Joel H. Weiner
- School of Molecular and Systems Medicine, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Richard Rothery
- School of Molecular and Systems Medicine, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Graham N. George
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
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13
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Salinier V, Corker J, Lefebvre F, Bayard F, Dufaud V, Basset JM. Silica-Supported Zirconium Complexes and their Polyoligosilsesquioxane Analogues in the Transesterification of Acrylates: Part 1. Synthesis and Characterization. Adv Synth Catal 2009. [DOI: 10.1002/adsc.200900273] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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14
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Allender CJ, Castell OK, Davies PR, Fiddy S, Hedin-Dahlström J, Stockenhuber M. A glimpse of the inner workings of the templated site. Chem Commun (Camb) 2009:165-7. [DOI: 10.1039/b811578h] [Citation(s) in RCA: 7] [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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15
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Chen X, Cai Q, Wang W, Mo G, Jiang L, Zhang K, Chen Z, Wu Z, Wu Z. In-Situ Heating Study on the Structural Change of Surfactant-Templated Germanium Oxide Mesostructure. J Phys Chem B 2008; 112:12297-303. [DOI: 10.1021/jp803407a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xing Chen
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China, General Research Institute for Nonforrous Metals, Beijing 100088, China, and Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Quan Cai
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China, General Research Institute for Nonforrous Metals, Beijing 100088, China, and Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Wang
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China, General Research Institute for Nonforrous Metals, Beijing 100088, China, and Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Guang Mo
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China, General Research Institute for Nonforrous Metals, Beijing 100088, China, and Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Longsheng Jiang
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China, General Research Institute for Nonforrous Metals, Beijing 100088, China, and Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Kunhao Zhang
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China, General Research Institute for Nonforrous Metals, Beijing 100088, China, and Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zhongjun Chen
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China, General Research Institute for Nonforrous Metals, Beijing 100088, China, and Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Ziyu Wu
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China, General Research Institute for Nonforrous Metals, Beijing 100088, China, and Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zhonghua Wu
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China, General Research Institute for Nonforrous Metals, Beijing 100088, China, and Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
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16
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Nordhei C, Ramstad AL, Nicholson DG. Nanophase cobalt, nickel and zinc ferrites: synchrotronXAS study on the crystallite size dependence of metal distribution. Phys Chem Chem Phys 2008; 10:1053-66. [PMID: 18259645 DOI: 10.1039/b711918f] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Camilla Nordhei
- Department of Chemistry, Norwegian University of Science & Technology, Høgskoleringen 5, N-7491, Trondheim, Norway.
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17
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Nemana S, Gates BC. Surface-mediated synthesis and spectroscopic characterization of tantalum clusters on silica. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:8214-20. [PMID: 16952265 DOI: 10.1021/la0609322] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Tantalum clusters were synthesized on the surface of porous silica by treatment of adsorbed Ta(CH(2)Ph)(5) in H(2) at temperatures in the range of 523-723 K. The surface species were characterized by UV-vis, far-infrared, and extended X-ray absorption fine-structure (EXAFS) spectroscopies, each of which provided evidence of Ta-Ta bonds similar to those in well-characterized molecular tantalum clusters. The Ta-Ta distance determined by EXAFS spectroscopy was 2.93 A. The chemistry of the cluster synthesis is similar to that of syntheses of similar tantalum clusters in solution. The supported clusters formed at 523 K are characterized by an EXAFS first-shell Ta-Ta coordination number of nearly 2, indicative of tri-tantalum clusters, although it is expected that a mixture of clusters was present, and reduction in H(2) at higher temperatures led to larger tantalum clusters. This is the first example of the surface-mediated synthesis of an early transition metal cluster, and the supported clusters reported here are the first to have been characterized by all three of the spectroscopic methods mentioned above. The similarity of the surface synthesis to that in solution points to opportunities to extend this new class of material to other early transition metal clusters on various supports.
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Affiliation(s)
- Sailendra Nemana
- Department of Chemical Engineering and Materials Science, University of California, Davis, California 95616, USA
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18
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Gervasini A, Manzoli M, Martra G, Ponti A, Ravasio N, Sordelli L, Zaccheria F. Dependence of Copper Species on the Nature of the Support for Dispersed CuO Catalysts. J Phys Chem B 2006; 110:7851-61. [PMID: 16610882 DOI: 10.1021/jp056604c] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Copper catalysts prepared by chemisorption-hydrolysis technique over silica (Cu/Si) and silica-alumina (Cu/SiAl) supports were studied to understand the role of the support on the nature and surface properties of the copper species stabilized on their surfaces. The morphological and surface properties of the copper phases have been characterized by complementary techniques, such as HRTEM, EXAFS-XANES, EPR, XPS, and FTIR. For the FTIR investigation, molecular probes (CO and NO) were also adsorbed on the surfaces to test the reactivity of the copper species. Moreover, the catalytic performances of the two catalysts have been compared in the HC-SCR reaction (NO reduction by C(2)H(4)) performed in highly oxidant conditions. The superior activity and selectivity of the supported silica-alumina catalyst with respect to that supported on silica could be related with the different nature of the copper species stabilized on the two supports, as emerged from the results obtained from the spectroscopic investigations. Small and well-dispersed CuO particles were present on silica, whereas isolated copper ions predominated on silica-alumina, likely in regions rich in alumina that made some exchangeable sites available, as indicated by FTIR spectra of adsorbed CO. The less positive global charge of copper species on Cu/SiAl than in Cu/Si has been confirmed by EPR, XPS, and EXAFS-XANES analyses.
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Affiliation(s)
- Antonella Gervasini
- Dipartimento di Chimica Fisica ed Elettrochimica & Centro di Eccellenza CIMAINA, Università degli Studi di Milano, via C. Golgi 19, 20133 Milan, Italy.
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Surblé S, Millange F, Serre C, Férey G, Walton RI. An EXAFS study of the formation of a nanoporous metal–organic framework: evidence for the retention of secondary building units during synthesis. Chem Commun (Camb) 2006:1518-20. [PMID: 16575446 DOI: 10.1039/b600709k] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
EXAFS data measured from amorphous intermediates and crystallisation solutions provides the first evidence that trimeric iron oxide secondary building units remain intact during crystallisation of the metal-organic framework MIL-89 from starting materials to products.
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Affiliation(s)
- Suzy Surblé
- Institut Lavoisier, UMR CNRS 8637, Université de Versailles St-Quentin en Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France
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20
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Izzet G, Frapart YM, Prangé T, Provost K, Michalowicz A, Reinaud O. X-ray Diffraction and EXAFS Studies of Hydroxo−Cu(II) Complexes Based on a Calix[6]arene-N3 Ligand: Evidence for a Mononuclear−Dinuclear Equilibrium Controlled by Supramolecular Features. Inorg Chem 2005; 44:9743-51. [PMID: 16363843 DOI: 10.1021/ic0511322] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The formation of hydroxo complexes based on a calix[6]trisimidazole ligand is described. Deprotonation of the mononuclear Cu(II)-aqua complex gives rise to a dinuclear bis(mu-hydroxo) complex that has been characterized by X-ray diffraction analysis. Spectroscopic studies (EPR and UV-vis), conducted in dichloromethane solutions in the presence of various coordinating cosolvents (DMF, EtOH, or RCN) or with acetamide, revealed the coexistence of a mononuclear hydroxo species. The latter could be trapped by acetic acid to provide an acetato-Cu(II) complex that presents close spectroscopic features. An EXAFS study first conducted on the hydroxo-Cu(II) complex led to an excellent fit for the dinuclear core. It then allowed for the characterization of the mononuclear acetato complex with an acetamide guest included in the calixarene cavity. Hence, this study illustrates the flexibility of calixarene-based ligands and the role of the second coordination sphere in the stabilization of acidic or basic Cu(II) complexes.
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Affiliation(s)
- Guillaume Izzet
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR CNRS 8601, Université René Descartes, 45 rue des Saints-Pères, 75270 Paris Cedex 06, France
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21
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Deguns EW, Taha Z, Meitzner GD, Scott SL. An X-ray Absorption Study of Two VOCl3-Modified Silicas: Evidence for Chloride−Silica Interactions. J Phys Chem B 2005; 109:5005-11. [PMID: 16863160 DOI: 10.1021/jp045886y] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structures of the sites formed in the gas-solid reactions of VOCl3 with the surfaces of a fumed silica (Aerosil) and a silica gel (Sylopol) were investigated by using X-ray absorption spectroscopy. XANES and EXAFS analysis at the vanadium K-edge reveal that the sites have a uniform first coordination sphere regardless of the origin or the extent of hydroxylation of the silica support (controlled by thermal treatment in vacuo at 100 and 500 degrees C). Analysis of the second coordination sphere was limited by the lack of structural uniformity. EXAFS curve-fitting confirmed that the sites are [triple bond]SiOVOCl2, but revealed an unexpected asymmetry in the V-Cl bond distances. The latter is suggested to be a manifestation of silicon-chloride interactions.
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Affiliation(s)
- Eric W Deguns
- Department of Chemistry, University of California, Santa Barbara, California 93106-5080, USA
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22
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Abstract
Extended x-ray absorption fine structure (EXAFS) spectroscopy was combined with thermodynamic and kinetic approaches to investigate zinc binding to a zinc finger (C2H2) and a tetrathiolate (C4) peptide. Both peptides represent structural zinc sites of proteins and rapidly bind a single zinc ion with picomolar dissociation constants. In competition with EDTA the transfer of peptide-bound zinc ions proved to be 6 orders of magnitude faster than predicted for a dissociation-association mechanism thus requiring ligand exchange mechanisms via peptide-zinc-EDTA complexes. EXAFS spectra of C2H2 showed the expected Cys2His2-ligand geometry when fully loaded with zinc. For a 2-fold excess of peptide, however, the existence of zinc-bridged peptide-peptide complexes with dominating sulfur coordination could be clearly shown. Whereas zinc binding kinetics of C2H2 appeared as a simple second order process, the suggested mechanism for C4 comprises a zinc-bridged Zn-(C4)2 species as well as a Zn-C4 species with less than 4 metal-bound thiolates, which is supported by EXAFS results. A rapid equilibrium of bound and unbound states of individual ligands might explain the kinetic instability of zinc-peptide complexes, which enables fast ligand exchange during the encounter of occupied and unoccupied acceptor sites. Depending on relative concentrations and stabilities, this results in a rapid transfer of zinc ions in the virtual absence of free zinc ions, as seen for the zinc transfer to EDTA, or in the formation of zinc-bridged complexes, as seen for both peptides with excess of peptides over available zinc.
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Affiliation(s)
- Uwe Heinz
- Department of Natural Sciences, The Royal Veterinary and Agricultural University, DK-1871 Frederiksberg C, Denmark
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Ramstad AL, Mikkelsen Ø. Structural characterisation of copper-containing manganese oxide octahedral molecular sieve (Cu-OMS-2) materials by X-ray absorption spectroscopy and cyclic voltammetry. J Mol Struct 2004. [DOI: 10.1016/j.molstruc.2004.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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25
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A soft X-ray exafs study of the local structure of tetrahedral aluminium in zeolites. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s0167-2991(04)80657-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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26
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Patel N, Seward HE, Svensson A, Gurman SJ, Thomson AJ, Raven EL. Exploiting the conformational flexibility of leghemoglobin: a framework for examination of heme protein axial ligation. Arch Biochem Biophys 2003; 418:197-204. [PMID: 14522591 DOI: 10.1016/s0003-9861(03)00403-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have exploited the intrinsic conformational flexibility of leghemoglobin to reengineer the heme active site architecture of the molecule by replacement of the mobile His61 residue with tyrosine (H61Y variant). The electronic absorption spectrum of the ferric derivative of H61Y is similar to that observed for the phenolate derivative of the recombinant wild-type protein (rLb), consistent with coordination of Tyr61 to (high-spin) iron. EXAFS data clearly indicate a 6-coordinate heme geometry and a Fe-O bond length of 185pm. MCD and EPR spectroscopies are consistent with this assignment and support ligation by an anionic (tyrosinate) group. The alteration in heme ligation leads to a 148mV decrease in the reduction potential for H61Y (-127+/-5mV) compared to rLb and destabilisation of the functional oxy-derivative. The results are discussed in terms of our wider understanding of other heme proteins with His-Tyr ligation.
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Affiliation(s)
- Neesha Patel
- Department of Chemistry, University of Leicester, University Road, LE1 7RH, England, Leicester, UK
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27
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Nunes CD, Pillinger M, Hazell A, Jepsen J, Santos TM, Madureira J, Lopes AD, Gonçalves IS. Bimetallic transition metal–ruthenium(II) complexes containing bridging bipyrimidine ligands. Polyhedron 2003. [DOI: 10.1016/s0277-5387(03)00397-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Heinz U, Bauer R, Wommer S, Meyer-Klaucke W, Papamichaels C, Bateson J, Adolph HW. Coordination geometries of metal ions in d- or l-captopril-inhibited metallo-beta-lactamases. J Biol Chem 2003; 278:20659-66. [PMID: 12668674 DOI: 10.1074/jbc.m212581200] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
d- and l-captopril are competitive inhibitors of metallo-beta-lactamases. For the enzymes from Bacillus cereus (BcII) and Aeromonas hydrophila (CphA), we found that the mononuclear enzymes are the favored targets for inhibition. By combining results from extended x-ray absorption fine structure, perturbed angular correlation of gamma-rays spectroscopy, and a study of metal ion binding, we derived that for Cd(II)1-BcII, the thiolate sulfur of d-captopril binds to the metal ion located at the site defined by three histidine ligand residues. This is also the case for the inhibited Co(II)1 and Co(II)2 enzymes as observed by UV-visible spectroscopy. Although the single metal ion in Cd(II)1-BcII is distributed between both available binding sites in both the uninhibited and the inhibited enzyme, Cd(II)1-CphA shows only one defined ligand geometry with the thiolate sulfur coordinating to the metal ion in the site composed of 1 Cys, 1 His, and 1 Asp. CphA shows a strong preference for d-captopril, which is also reflected in a very rigid structure of the complex as determined by perturbed angular correlation spectroscopy. For BcII and CphA, which are representatives of the metallo-beta-lactamase subclasses B1 and B2, we find two different inhibitor binding modes.
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Affiliation(s)
- Uwe Heinz
- Department of Biochemistry, University of the Saarland, D-66041 Saarbruecken, Germany
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29
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Nunes C, Pillinger M, Valente A, Gonçalves I, Rocha J, Ferreira P, Kühn F. Synthesis and Characterization of Methyltrioxorhenium(VII) Immobilized in Bipyridyl-Functionalized Mesoporous Silica. Eur J Inorg Chem 2002. [DOI: 10.1002/1099-0682(200205)2002:5<1100::aid-ejic1100>3.0.co;2-b] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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30
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Influence of Pretreatment Temperature on the Bimetallic Interactions in Pt-Re/Al2O3 Reforming Catalysts Studied by X-Ray Absorption Spectroscopy. J Catal 2001. [DOI: 10.1006/jcat.2001.3399] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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31
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de Seny D, Heinz U, Wommer S, Kiefer M, Meyer-Klaucke W, Galleni M, Frere JM, Bauer R, Adolph HW. Metal ion binding and coordination geometry for wild type and mutants of metallo-beta -lactamase from Bacillus cereus 569/H/9 (BcII): a combined thermodynamic, kinetic, and spectroscopic approach. J Biol Chem 2001; 276:45065-78. [PMID: 11551939 DOI: 10.1074/jbc.m106447200] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
One high affinity (nm) and one low affinity (microM) macroscopic dissociation constant for the binding of metal ions were found for the wild-type metallo-beta-lactamase from Bacillus cereus as well as six single-site mutants in which all ligands in the two metal binding sites were altered. Surprisingly, the mutations did not cause a specific alteration of the affinity of metal ions for the sole modified binding site as determined by extended x-ray absorption fine structure (EXAFS) and perturbed angular correlation of gamma-rays spectroscopy, respectively. Also UV-visible absorption spectra for the mono-cobalt enzymes clearly contain contributions from both metal sites. The observations of the very similar microscopic dissociation constants of both binding sites in contrast to the significantly differing macroscopic dissociation constants inevitably led to the conclusion that binding to the two metal sites exhibits negative cooperativity. The slow association rates for forming the binuclear enzyme determined by stopped-flow fluorescence measurements suggested that fast metal exchange between the two sites for the mononuclear enzyme hinders the binding of a second metal ion. EXAFS spectroscopy of the mono- and di-zinc wild type enzymes and two di-zinc mutants provide a definition of the metal ion environments, which is compared with the available x-ray crystallographic data.
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Affiliation(s)
- D de Seny
- Centre d'Ingéniérie des Protéines, Institut de Chimie B6, Université de Liège, Sart-Tilman, B-4000 Liège, Belgium
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32
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A square-planar di-N-carboxamido, dithiolato–cobalt(III) complex related to nitrile hydratase metallic site. Addition of axial ligands and EXAFS study of the derived dicyano and diisocyanido complexes. Inorganica Chim Acta 2001. [DOI: 10.1016/s0020-1693(01)00413-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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33
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Jentys A, Simon L, Lercher JA. On the Determination of the Location of Metal Clusters Supported on Molecular Sieves by X-ray Absorption Spectroscopy. J Phys Chem B 2000. [DOI: 10.1021/jp001429f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andreas Jentys
- Institute for Chemical Technology, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany, and Catalytic Processes and Materials, Faculty of Chemical Technology, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Laurent Simon
- Institute for Chemical Technology, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany, and Catalytic Processes and Materials, Faculty of Chemical Technology, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Johannes A. Lercher
- Institute for Chemical Technology, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany, and Catalytic Processes and Materials, Faculty of Chemical Technology, P.O. Box 217, 7500 AE Enschede, The Netherlands
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35
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Characterization of the Nickel Cobaltite, NiCo2O4, Prepared by Several Methods: An XRD, XANES, EXAFS, and XPS Study. J SOLID STATE CHEM 2000. [DOI: 10.1006/jssc.2000.8749] [Citation(s) in RCA: 549] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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36
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van Koningsbruggen PJ, Garcia Y, Kahn O, Fournès L, Kooijman H, Spek AL, Haasnoot JG, Moscovici J, Provost K, Michalowicz A, Renz F, Gütlich P. Synthesis, crystal structure, EXAFS, and magnetic properties of catena [mu-tris(1,2-bis(tetrazol-1-yl)propane-N1,N1')iron(II)] bis(perchlorate). First crystal structure of an iron(II) spin-crossover chain compound. Inorg Chem 2000; 39:1891-900. [PMID: 11428109 DOI: 10.1021/ic991118n] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[Fe(btzp)3](ClO4)2 (btzp = 1,2-bis(tetrazol-1-yl)propane) represents the first structurally characterized Fe(II) linear chain compound exhibiting thermal spin crossover. It shows a very gradual spin transition (T1/2 = 130 K) which has been followed by magnetic susceptibility measurements and 57Fe Mössbauer spectroscopy. The structure has been solved at 200 and 100 K by single-crystal X-ray analysis. It crystallizes in the trigonal space group P3c1 with Z = 2 Fe(II) units at both temperatures. The molecular structure consists of chains running along the c axis in which the Fe(II) ions are linked by three N4,N4' coordinating bis(tetrazole) ligands. The main difference between the two forms appears to be in the Fe-N bond lengths, which are 2.164(4) A at 200 K and 2.038(4) A at 100 K. The Fe-Fe separations are 7.422(1) A at 200 K and 7.273(1) A at 100 K. The EXAFS results are consistent with the crystal structure. In both spin states, the FeN6 octahedron is almost regular within the EXAFS resolution. The Fe-N distance is found as 2.16(2) A at 300 K and 2.00(2) A at 40 K. The absence of the "7 A peak" in the EXAFS spectra of [Fe(btzp)3](ClO4)2, in contrast with what has been observed for the [Fe(4-R-1,2,4-triazole)3]-(anion)2 chain compounds, confirms that this peak can be used as the signature of a metal alignment only when it involves a strongly enhanced multiple scattering M-M-M path, with M-M spacing less than 4 A. Irradiation with green light at 5 K has led to the population of the metastable high-spin state for the iron(II) ion. The nature of the spin-crossover behavior has been discussed on the basis of the structural features.
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Affiliation(s)
- P J van Koningsbruggen
- Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg University, Staudingerweg 9, D-55099 Mainz, Germany
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37
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Stockenhuber M, Hudson MJ, Joyner RW. Preparation, Characterization, and Unusual Reactivity of Fe-MCM-41. J Phys Chem B 2000. [DOI: 10.1021/jp993355h] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michael Stockenhuber
- Catalysis Research Laboratory, Department of Chemistry and Physics, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K., and Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, U.K
| | - Michael J. Hudson
- Catalysis Research Laboratory, Department of Chemistry and Physics, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K., and Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, U.K
| | - Richard W. Joyner
- Catalysis Research Laboratory, Department of Chemistry and Physics, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K., and Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, U.K
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Feiters MC, Gebbink RJMK, Solé VA, Nolting HF, Karlin KD, Nolte RJM. X-ray Absorption Spectroscopic Studies of the Copper(I) Complexes of Crown Ether Appended Bis{(2-pyridyl)ethyl}amines and Their Dioxygen Adducts. Inorg Chem 1999; 38:6171-6180. [PMID: 11671329 DOI: 10.1021/ic990056y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An X-ray absorption spectroscopic study of the Cu complexes of the bis{(2-pyridyl)ethyl}-appended monoaza crown ether 1, diaza crown ether 2, and diphenylglycoluril diaza basket 3 is reported. Following detailed analysis of the spectra of the crystallographically characterized model compound tetrapyridyl Cu(II) bis(nitrato pyridine) (4), the contributions of the ring atoms of the coordinating pyridine to the EXAFS were simulated using a multiple-scattering approach and the final parameters obtained by restrained refinement. Oxygenation of the Cu(I) complexes resulted in a large increase of the intensity of the major peak in the phase-corrected Fourier transform. This was interpreted as evidence for a &mgr;-eta(2):eta(2)-peroxo coordination mode of the oxygen between the copper ions, which had changed valence from Cu(I) to Cu(II) as judged from the edge position. This oxygen binding mode is reminiscent of that of hemocyanin, but the Cu-Cu distances are significantly shorter in the model than in the enzyme and vary with solvent. The EXAFS of the oxygenated complexes was simulated in a new approach in which, besides the parameters of the pyridine unit, those of an additional multiple scattering unit describing the geometry of the Cu-O(2)-Cu moiety were also refined.
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Affiliation(s)
- Martinus C. Feiters
- Department of Organic Chemistry, NSR Center, University of Nijmegen, Toernooiveld, NL-6525 ED Nijmegen, The Netherlands, EMBL Outstation at DESY, Notkestrasse 85, 22603 Hamburg, Germany, and Department of Chemistry, Johns Hopkins University, Charles & 34th Streets, Baltimore, Maryland 21218
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42
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Joyner R, Stockenhuber M. Preparation, Characterization, and Performance of Fe−ZSM-5 Catalysts. J Phys Chem B 1999. [DOI: 10.1021/jp990978m] [Citation(s) in RCA: 213] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Richard Joyner
- Catalysis Research Laboratory, Department of Chemistry and Physics, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
| | - Michael Stockenhuber
- Catalysis Research Laboratory, Department of Chemistry and Physics, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
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Banger KK, Brisdon AK. The first early transition metal perfluorovinyl complexes: the synthesis of Cp2M(CFCF2)nX2−n (Cp: η5-C5H5−; M=Ti, Zr; X=Cl or F) and structures of Cp2Ti(CFCF2)nX2−n (X=Cl, F) via Ti K-edge EXAFS studies. J Organomet Chem 1999. [DOI: 10.1016/s0022-328x(99)00073-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Drabløs F, Nicholson DG, Rønning M. EXAFS study of zinc coordination in bacitracin A. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1431:433-42. [PMID: 10350618 DOI: 10.1016/s0167-4838(99)00064-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Bacitracin is a dodecapeptide antibiotic produced by Bacillus sp. The antibacterial activity depends upon the peptide binding a divalent metal. Hitherto, the exact coordination of the cation has not been established. In particular the role played by the sulphur and nitrogen atoms of the thiazoline ring of bacitracin A has not been clear. Here the coordination of Zn2+ by bacitracin A has been studied using extended X-ray absorption fine structure. The experimental data are consistent with a model in which zinc is coordinated by one oxygen and three nitrogen atoms with the sulphur atom of the thiazoline ring not being directly involved in the zinc coordination.
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Affiliation(s)
- F Drabløs
- SINTEF Unimed MR Centre, N-7465, Trondheim, Norway.
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Pattrick R, England K, Charnock J, Mosselmans J. Copper activation of sphalerite and its reaction with xanthate in relation to flotation: an X-ray absorption spectroscopy (reflection extended X-ray absorption fine structure) investigation. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0301-7516(98)00036-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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46
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George GN, Hilton J, Temple C, Prince RC, Rajagopalan KV. Structure of the Molybdenum Site of Dimethyl Sulfoxide Reductase. J Am Chem Soc 1999. [DOI: 10.1021/ja982843k] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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47
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Brown AR, Guo Z, Mosselmans FWJ, Parsons S, Schröder M, Yellowlees LJ. Structural and Voltammetric Studies on the Reduction of the Bis(2,2‘-bipyridyl)platinum(II) Cation in Aprotic Media. J Am Chem Soc 1998. [DOI: 10.1021/ja981670w] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alan R. Brown
- Contribution from the Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, U.K., Synchrotron Radiation Department, Daresbury Laboratory, Daresbury, Cheshire WA4 4AD, U.K., and Department of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Zijian Guo
- Contribution from the Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, U.K., Synchrotron Radiation Department, Daresbury Laboratory, Daresbury, Cheshire WA4 4AD, U.K., and Department of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Fred W. J. Mosselmans
- Contribution from the Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, U.K., Synchrotron Radiation Department, Daresbury Laboratory, Daresbury, Cheshire WA4 4AD, U.K., and Department of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Simon Parsons
- Contribution from the Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, U.K., Synchrotron Radiation Department, Daresbury Laboratory, Daresbury, Cheshire WA4 4AD, U.K., and Department of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Martin Schröder
- Contribution from the Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, U.K., Synchrotron Radiation Department, Daresbury Laboratory, Daresbury, Cheshire WA4 4AD, U.K., and Department of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Lesley J. Yellowlees
- Contribution from the Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, U.K., Synchrotron Radiation Department, Daresbury Laboratory, Daresbury, Cheshire WA4 4AD, U.K., and Department of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
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Clark-Baldwin K, Tierney DL, Govindaswamy N, Gruff ES, Kim C, Berg J, Koch SA, Penner-Hahn JE. The Limitations of X-ray Absorption Spectroscopy for Determining the Structure of Zinc Sites in Proteins. When Is a Tetrathiolate Not a Tetrathiolate? J Am Chem Soc 1998. [DOI: 10.1021/ja980580o] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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50
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Lamberti C, Bordiga S, Arduino D, Zecchina A, Geobaldo F, Spanó G, Genoni F, Petrini G, Carati A, Villain F, Vlaic G. Evidence of the Presence of Two Different Framework Ti(IV) Species in Ti−Silicalite-1 in Vacuo Conditions: an EXAFS and a Photoluminescence Study. J Phys Chem B 1998. [DOI: 10.1021/jp981225n] [Citation(s) in RCA: 154] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | - F. Geobaldo
- Dipartimento di Scienza dei Materiali e Ingegneria Chimica, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino, Italy
| | | | | | | | - A. Carati
- EniTecnologie, Via F. Maritano 26, I-20097 S. Donato (Mi), Italy
| | - F. Villain
- LURE, Université Paris-Sud, 91405 Orsay Cedex, France
| | - G. Vlaic
- Dipartimento di Scienze Chimiche, Via Valerio 28, Trieste, and Sincrotrone Trieste SCpA, Padriciano 99, I-34012 Trieste, Italy
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