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Chevalier F, Schlathölter T, Poully JC. Radiation-Induced Transfer of Charge, Atoms, and Energy within Isolated Biomolecular Systems. Chembiochem 2023; 24:e202300543. [PMID: 37712497 DOI: 10.1002/cbic.202300543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/16/2023]
Abstract
In biological tissues, ionizing radiation interacts with a variety of molecules and the consequences include cell killing and the modification of mechanical properties. Applications of biological radiation action are for instance radiotherapy, sterilization, or the tailoring of biomaterial properties. During the first femtoseconds to milliseconds after the initial radiation action, biomolecular systems typically respond by transfer of charge, atoms, or energy. In the condensed phase, it is usually very difficult to distinguish direct effects from indirect effects. A straightforward solution for this problem is the use of gas-phase techniques, for instance from the field of mass spectrometry. In this review, we survey mainly experimental but also theoretical work, focusing on radiation-induced intra- and inter-molecular transfer of charge, atoms, and energy within biomolecular systems in the gas phase. Building blocks of DNA, proteins, and saccharides, but also antibiotics are considered. The emergence of general processes as well as their timescales and mechanisms are highlighted.
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Affiliation(s)
- François Chevalier
- CIMAP UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Normandie, Bd Becquerel, 14070, Caen, France
| | - Thomas Schlathölter
- Zernike Institute for Advanced Materials, University of Groningen, Groningen (The, Netherlands
- University College Groningen, University of Groningen, Groningen (The, Netherlands
| | - Jean-Christophe Poully
- CIMAP UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Normandie, Bd Becquerel, 14070, Caen, France
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2
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de Kock S, Skudler K, Matsidik R, Sommer M, Müller M, Walter M. NEXAFS spectra of model sulfide chains: implications for sulfur networks obtained from inverse vulcanization. Phys Chem Chem Phys 2023; 25:20395-20404. [PMID: 37465922 DOI: 10.1039/d3cp02285d] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Inverse vulcanization is a promising route to stabilize sulfur in lithium-sulfur batteries, but the resulting sulfur strand lengths in the materials are elusive. We address the strand length by characterization via sulfur near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Theoretical predictions of NEXAFS spectra for model molecules containing strands with up to three sulfur atoms are verified by experiment. The near perfect agreement between simulation and experiment on the absolute energy scale allows for the predictions for larger chain lengths also. Inspection and interpretation of NEXAFS spectra from real battery materials on this basis reveals the appearance of single connecting sulfur atoms for very low sulfur content, and of longer strands when the sulfur fraction increases.
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Affiliation(s)
- Sunel de Kock
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, Georges-Köhler-Allee 105, 79110 Freiburg, Germany.
| | - Konstantin Skudler
- Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany
| | - Rukiya Matsidik
- Institute for Chemistry, Polymer Chemistry, Chemnitz University of Technology, 09111 Chemnitz, Germany
- Forschungszentrum MAIN, TU Chemnitz, Rosenbergstraße 6, 09126 Chemnitz, Germany
| | - Michael Sommer
- Institute for Chemistry, Polymer Chemistry, Chemnitz University of Technology, 09111 Chemnitz, Germany
- Forschungszentrum MAIN, TU Chemnitz, Rosenbergstraße 6, 09126 Chemnitz, Germany
| | - Matthias Müller
- Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany
| | - Michael Walter
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, Georges-Köhler-Allee 105, 79110 Freiburg, Germany.
- Cluster of Excellence livMatS @ FIT, Freiburg, Germany
- Fraunhofer IWM, MikroTribologie Centrum μTC, Freiburg, Germany
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3
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Nehzati S, Dolgova NV, James AK, Cotelesage JJH, Sokaras D, Kroll T, George GN, Pickering IJ. High Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy: An Analytical Method for Selenium Speciation. Anal Chem 2021; 93:9235-9243. [PMID: 34164981 DOI: 10.1021/acs.analchem.1c01503] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Selenium is in many ways an enigmatic element. It is essential for health but toxic in excess, with the difference between the two doses being narrower than for any other element. Environmentally, selenium is of concern due to its toxicity. As the rarest of the essential elements, its low levels often provide challenges to the analytical chemist. X-ray absorption spectroscopy (XAS) provides a powerful tool for in situ chemical speciation but is severely limited by poor spectroscopic resolution arising from core-hole lifetime broadening. Here we explore selenium Kα1 high energy resolution fluorescence detected XAS (HERFD-XAS) as a novel approach for chemical speciation of selenium, in comparison with conventional Se K-edge XAS. We present spectra of a range of selenium species relevant to environmental and life science studies, including spectra of seleno-amino acids, which show strong similarities with S K-edge XAS of their sulfur congeners. We discuss strengths and limitations of HERFD-XAS, showing improvements in both speciation performance and low concentration detection. We also develop a simple method to correct fluorescence self-absorption artifacts, which is generally applicable to any HERFD-XAS experiment.
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Affiliation(s)
- Susan Nehzati
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Natalia V Dolgova
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Ashley K James
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada.,Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Julien J H Cotelesage
- Molecular and Environmental Sciences Group, 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, United States
| | - Thomas Kroll
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Graham N George
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada.,Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada.,Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Ingrid J Pickering
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada.,Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada.,Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9, Canada
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4
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Sulfur Species, Bonding Environment, and Metal Mobilization in Mining-Impacted Lake Sediments: Column Experiments Replicating Seasonal Anoxia and Deposition of Algal Detritus. MINERALS 2020. [DOI: 10.3390/min10100849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The oxidation state of sulfur [S] is a primary control on mobility of metals in sediments impacted by legacy mining practices. Coeur d’Alene Lake of northern Idaho, USA, has been impacted by upstream legacy mining practices that deposited an estimated 75 Mt of metal(loid)- and S-rich sediments into the lake. Future lake conditions are expected to include algal blooms, which may alter S and metal remobilization during the seasonal euxinic environment. Cores of the lake sediments were exposed to anoxic and anoxic + algal detritus conditions for eight weeks at 4.5 °C through introduction of a N2 atmosphere and addition of algal detritus. At a location 2.5 cm below the sediment-water interface, anoxic conditions promoted a shift in S species to continually larger concentrations of reduced species and an associated shift in the bonding environment reflective of increased S–metal bonds. Anoxic + algal detritus conditions suppressed the increasing trend of reduced S species and induced greater release of Mn compared to the anoxic-only conditions but did not appear to enhance the release of As, Cd, or Fe. The addition of algal detritus to the sediment-water interface of these Fe- and S-rich sediments enhanced mobilization of Mn likely because of dissimilatory metal reduction where the anaerobic oxidation of the algal detritus stimulated Mn reduction. Results of the study indicate that future metal release from the lake sediments will be altered with the likely deposition of algal detritus, but the effect may not enhance the release of acutely toxic metals, such as As or Cd, or substantially impact Fe cycling in the sediments.
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5
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Effect of 1-octanethiol as an electrolyte additive on the performance of the iron-air battery electrodes. J Solid State Electrochem 2020. [DOI: 10.1007/s10008-020-04738-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractIt has recently been established that 1-octanethiol in the electrolyte can allow iron electrodes to be discharged at higher rates. However, the effect of thiol additives on the air electrode has not yet been studied. The effect of solvated thiols on the surface positive electrode reaction is of prime importance if these are to be used in an iron-air battery. This work shows that the air-electrode catalyst is poisoned by the presence of octanethiol, with the oxygen reduction overpotential at the air electrode increasing with time of exposure to the solution and increased 1-octanethiol concentration in the range 0–0.1 mol dm−3. Post-mortem XPS analyses were performed over the used air electrodes suggesting the adsorption of sulphur species over the catalyst surface, reducing its performance. Therefore, although sulphur-based additives may be suitable for nickel-iron batteries, they are not recommended for iron-air batteries except in concentrations well below 10 × 10−3 mol dm−3.
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6
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Schwob L, Dörner S, Atak K, Schubert K, Timm M, Bülow C, Zamudio-Bayer V, von Issendorff B, Lau JT, Techert S, Bari S. Site-Selective Dissociation upon Sulfur L-Edge X-ray Absorption in a Gas-Phase Protonated Peptide. J Phys Chem Lett 2020; 11:1215-1221. [PMID: 31978303 DOI: 10.1021/acs.jpclett.0c00041] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Site-selective dissociation induced by core photoexcitation of biomolecules is of key importance for the understanding of radiation damage processes and dynamics and for its promising use as "chemical scissors" in various applications. However, identifying products of site-selective dissociation in large molecules is challenging at the carbon, nitrogen, and oxygen edges because of the high recurrence of these atoms and related chemical groups. In this paper, we present the observation of site-selective dissociation at the sulfur L-edge in the gas-phase peptide methionine enkephalin, which contains only a single sulfur atom. Near-edge X-ray absorption mass spectrometry has revealed that the resonant S 2p → σ*C-S excitation of the sulfur contained in the methionine side chain leads to site-selective dissociation, which is not the case after core ionization above the sulfur L-edge. The prospects of such results for the study of charge dynamics in biomolecular systems are discussed.
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Affiliation(s)
- Lucas Schwob
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
| | - Simon Dörner
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
| | - Kaan Atak
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
| | - Kaja Schubert
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
| | - Martin Timm
- Abteilung für Hochempfindliche Röntgenspektroskopie , Helmholtz Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
| | - Christine Bülow
- Abteilung für Hochempfindliche Röntgenspektroskopie , Helmholtz Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
| | - Vicente Zamudio-Bayer
- Abteilung für Hochempfindliche Röntgenspektroskopie , Helmholtz Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
| | - Bernd von Issendorff
- Physikalisches Institut , Universität Freiburg , Hermann-Herder-Straße 3 , 79104 Freiburg , Germany
| | - J Tobias Lau
- Abteilung für Hochempfindliche Röntgenspektroskopie , Helmholtz Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
- Physikalisches Institut , Universität Freiburg , Hermann-Herder-Straße 3 , 79104 Freiburg , Germany
| | - Simone Techert
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
- Institute of X-ray Physics , University of Göttingen , Friedrich-Hund-Platz 1 , 37077 Göttingen , Germany
| | - Sadia Bari
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
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7
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Derricotte WD, Evangelista FA. Localized Intrinsic Valence Virtual Orbitals as a Tool for the Automatic Classification of Core Excited States. J Chem Theory Comput 2017; 13:5984-5999. [DOI: 10.1021/acs.jctc.7b00493] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Wallace D. Derricotte
- Department of Chemistry and Cherry
L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Francesco A. Evangelista
- Department of Chemistry and Cherry
L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
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8
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Cotelesage JJH, Barney M, Vogt L, Pickering IJ, George GN. X-ray Absorption Spectroscopy of Aliphatic Organic Sulfides. J Phys Chem A 2017; 121:6256-6261. [DOI: 10.1021/acs.jpca.7b04395] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Julien J. H. Cotelesage
- Molecular
and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Monica Barney
- Chevron Energy Technology Company, Richmond, California 94802, United States
| | - Linda Vogt
- Molecular
and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
- Department
of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Ingrid J. Pickering
- Molecular
and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
- Department
of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Graham N. George
- Molecular
and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
- Department
of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9, Canada
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9
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Edwards NP, van Veelen A, Anné J, Manning PL, Bergmann U, Sellers WI, Egerton VM, Sokaras D, Alonso-Mori R, Wakamatsu K, Ito S, Wogelius RA. Elemental characterisation of melanin in feathers via synchrotron X-ray imaging and absorption spectroscopy. Sci Rep 2016; 6:34002. [PMID: 27658854 PMCID: PMC5034265 DOI: 10.1038/srep34002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 09/02/2016] [Indexed: 11/29/2022] Open
Abstract
Melanin is a critical component of biological systems, but the exact chemistry of melanin is still imprecisely known. This is partly due to melanin’s complex heterogeneous nature and partly because many studies use synthetic analogues and/or pigments extracted from their natural biological setting, which may display important differences from endogenous pigments. Here we demonstrate how synchrotron X-ray analyses can non-destructively characterise the elements associated with melanin pigment in situ within extant feathers. Elemental imaging shows that the distributions of Ca, Cu and Zn are almost exclusively controlled by melanin pigment distribution. X-ray absorption spectroscopy demonstrates that the atomic coordination of zinc and sulfur is different within eumelanised regions compared to pheomelanised regions. This not only impacts our fundamental understanding of pigmentation in extant organisms but also provides a significant contribution to the evidence-based colour palette available for reconstructing the appearance of fossil organisms.
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Affiliation(s)
- Nicholas P Edwards
- University of Manchester, School of Earth and Environmental Sciences, Williamson Research Centre for Molecular Environmental Science, M13 9PL, UK.,University of Manchester, School of Earth and Environmental Sciences, Interdisciplinary Centre for Ancient Life, Manchester M13 9PL, UK
| | - Arjen van Veelen
- University of Manchester, School of Earth and Environmental Sciences, Williamson Research Centre for Molecular Environmental Science, M13 9PL, UK.,University of Manchester, School of Earth and Environmental Sciences, Interdisciplinary Centre for Ancient Life, Manchester M13 9PL, UK
| | - Jennifer Anné
- University of Manchester, School of Earth and Environmental Sciences, Williamson Research Centre for Molecular Environmental Science, M13 9PL, UK.,University of Manchester, School of Earth and Environmental Sciences, Interdisciplinary Centre for Ancient Life, Manchester M13 9PL, UK
| | - Phillip L Manning
- University of Manchester, School of Earth and Environmental Sciences, Interdisciplinary Centre for Ancient Life, Manchester M13 9PL, UK.,College of Charleston, Department of Geology and Environmental Geosciences, Charleston, SC, 29424, USA
| | - Uwe Bergmann
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - William I Sellers
- University of Manchester, School of Earth and Environmental Sciences, Williamson Research Centre for Molecular Environmental Science, M13 9PL, UK.,University of Manchester, School of Earth and Environmental Sciences, Interdisciplinary Centre for Ancient Life, Manchester M13 9PL, UK
| | - Victoria M Egerton
- University of Manchester, School of Earth and Environmental Sciences, Interdisciplinary Centre for Ancient Life, Manchester M13 9PL, UK.,College of Charleston, Department of Geology and Environmental Geosciences, Charleston, SC, 29424, USA
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Roberto Alonso-Mori
- Linac Coherent Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Kazumasa Wakamatsu
- Department of Chemistry, Fujita Health University, School of Health Sciences, Toyoake, Aichi 470-1192, Japan
| | - Shosuke Ito
- Department of Chemistry, Fujita Health University, School of Health Sciences, Toyoake, Aichi 470-1192, Japan
| | - Roy A Wogelius
- University of Manchester, School of Earth and Environmental Sciences, Williamson Research Centre for Molecular Environmental Science, M13 9PL, UK.,University of Manchester, School of Earth and Environmental Sciences, Interdisciplinary Centre for Ancient Life, Manchester M13 9PL, UK
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10
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Pomerantz AE. Toward Molecule-Specific Geochemistry of Heavy Ends: Application to the Upstream Oil Industry. Ind Eng Chem Res 2016. [DOI: 10.1021/acs.iecr.6b00402] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrew E. Pomerantz
- Schlumberger-Doll Research, 1 Hampshire St., Cambridge, Massachusetts 02139, United States
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11
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Chemical sensitivity of sulfur 1s NEXAFS spectroscopy II: Speciation of disulfide functional groups. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2013.10.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Behyan S, Hu Y, Urquhart SG. Chemical sensitivity of sulfur 1s NEXAFS spectroscopy I: Speciation of sulfoxides and sulfones. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2013.10.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Behyan S, Hu Y, Urquhart SG. Sulfur 1s near edge x-ray absorption fine structure spectroscopy of thiophenic and aromatic thioether compounds. J Chem Phys 2013; 138:214302. [PMID: 23758366 DOI: 10.1063/1.4807604] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Thiophenic compounds are major constituents of fossil fuels and pose problems for fuel refinement. The quantification and speciation of these compounds is of great interest in different areas such as biology, fossil fuels studies, geology, and archaeology. Sulfur 1s Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy has emerged as a qualitative and quantitative method for sulfur speciation. A firm understanding of the sulfur 1s NEXAFS spectra of organosulfur species is required for these analytical studies. To support this development, the sulfur 1s NEXAFS spectra of simple thiols and thioethers were previously examined, and are now extended to studies of thiophenic and aromatic thioether compounds, in the gas and condensed phases. High-resolution spectra have been further analyzed with the aid of Improved Virtual Orbital (IVO) and Δ(self-consistent field) ab initio calculations. Experimental sulfur 1s NEXAFS spectra show fine features predicted by calculation, and the combination of experiment and calculation has been used to improve the assignment of spectroscopic features important for the speciation and quantification of sulfur compounds. Systematic differences between gas and condensed phases are also explored; these differences suggest a significant role for conformational effects in the NEXAFS spectra of condensed species.
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Affiliation(s)
- Shirin Behyan
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9, Canada
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14
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Sarangi R, Frank P, Benfatto M, Morante S, Minicozzi V, Hedman B, Hodgson KO. The x-ray absorption spectroscopy model of solvation about sulfur in aqueous L-cysteine. J Chem Phys 2013. [PMID: 23206038 DOI: 10.1063/1.4767350] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The environment of sulfur in dissolved aqueous L-cysteine has been examined using K-edge x-ray absorption spectroscopy (XAS), extended continuum multiple scattering (ECMS) theory, and density functional theory (DFT). For the first time, bound-state and continuum transitions representing the entire XAS spectrum of L-cysteine sulfur are accurately reproduced by theory. Sulfur K-edge absorption features at 2473.3 eV and 2474.2 eV represent transitions to LUMOs that are mixtures of S-C and S-H σ∗ orbitals significantly delocalized over the entire L-cysteine molecule. Continuum features at 2479, 2489, and 2530 eV were successfully reproduced using extended continuum theory. The full L-cysteine sulfur K-edge XAS spectrum could not be reproduced without addition of a water-sulfur hydrogen bond. Density functional theory analysis shows that although the Cys(H)S⋯H-OH hydrogen bond is weak (∼2 kcal) the atomic charge on sulfur is significantly affected by this water. MXAN analysis of hydrogen-bonding structures for L-cysteine and water yielded a best fit model featuring a tandem of two water molecules, 2.9 Å and 5.8 Å from sulfur. The model included a S(cys)⋯H-O(w1)H hydrogen-bond of 2.19 Å and of 2.16 Å for H(2)O(w1)⋯H-O(w2)H. One hydrogen-bonding water-sulfur interaction alone was insufficient to fully describe the continuum XAS spectrum. However, density functional theoretical results are convincing that the water-sulfur interaction is weak and should be only transient in water solution. The durable water-sulfur hydrogen bond in aqueous L-cysteine reported here therefore represents a break with theoretical studies indicating its absence. Reconciling the apparent disparity between theory and result remains the continuing challenge.
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Affiliation(s)
- Ritimukta Sarangi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
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15
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Bernini RB, da Silva LBG, Rodrigues FN, Coutinho LH, Rocha AB, de Souza GGB. Core level (S 2p) excitation and fragmentation of the dimethyl sulfide and dimethyldisulfide molecules. J Chem Phys 2012; 136:144307. [DOI: 10.1063/1.3701567] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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