1
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Corti L, Iuga D, Claridge JB, Rosseinsky MJ, Blanc F. Disorder and Oxide Ion Diffusion Mechanism in La 1.54Sr 0.46Ga 3O 7.27 Melilite from Nuclear Magnetic Resonance. J Am Chem Soc 2023; 145:21817-21831. [PMID: 37782307 PMCID: PMC10571088 DOI: 10.1021/jacs.3c04821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Indexed: 10/03/2023]
Abstract
Layered tetrahedral network melilite is a promising structural family of fast ion conductors that exhibits the flexibility required to accommodate interstitial oxide anions, leading to excellent ionic transport properties at moderate temperatures. Here, we present a combined experimental and computational magic angle spinning (MAS) nuclear magnetic resonance (NMR) approach which aims at elucidating the local configurational disorder and oxide ion diffusion mechanism in a key member of this structural family possessing the La1.54Sr0.46Ga3O7.27 composition. 17O and 71Ga MAS NMR spectra display complex spectral line shapes that could be accurately predicted using a computational ensemble-based approach to model site disorder across multiple cationic and anionic sites, thereby enabling the assignment of bridging/nonbridging oxygens and the identification of distinct gallium coordination environments. The 17O and 71Ga MAS NMR spectra of La1.54Sr0.46Ga3O7.27 display additional features not observed for the parent LaSrGa3O7 phase which are attributed to interstitial oxide ions incorporated upon cation doping and stabilized by the formation of five-coordinate Ga centers conferring framework flexibility. 17O high-temperature (HT) MAS NMR experiments capture exchange within the bridging oxygens at 130 °C and reveal coalescence of all oxygen signals in La1.54Sr0.46Ga3O7.27 at approximately 300 °C, indicative of the participation of both interstitial and framework oxide ions in the transport process. These results further supported by the coalescence of the 71Ga resonances in the 71Ga HT MAS NMR spectra of La1.54Sr0.46Ga3O7.27 unequivocally provide evidence of the conduction mechanism in this melilite phase and highlight the potential of MAS NMR spectroscopy to enhance the understanding of ionic motion in solid electrolytes.
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Affiliation(s)
- Lucia Corti
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
- Leverhulme
Research Centre for Functional Materials Design, Materials Innovation
Factory, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Dinu Iuga
- Department
of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - John B. Claridge
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
- Leverhulme
Research Centre for Functional Materials Design, Materials Innovation
Factory, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Matthew J. Rosseinsky
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
- Leverhulme
Research Centre for Functional Materials Design, Materials Innovation
Factory, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Frédéric Blanc
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
- Leverhulme
Research Centre for Functional Materials Design, Materials Innovation
Factory, University of Liverpool, Liverpool L69 7ZD, United Kingdom
- Stephenson
Institute for Renewable Energy, University
of Liverpool, Liverpool L69 7ZF, United Kingdom
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2
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Sulcek L, Langner R, Werner-Zwanziger U, Zwanziger JW, Martineau-Corcos C, Fechtelkord M. Solid-state nuclear magnetic resonance investigation of synthetic phlogopite and lepidolite samples. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2020; 58:1099-1108. [PMID: 31945203 DOI: 10.1002/mrc.4998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 01/09/2020] [Accepted: 01/13/2020] [Indexed: 06/10/2023]
Abstract
In the present work, our aim is to decipher the cationic ordering in the octahedral and tetrahedral sheets of two Al-rich synthetic materials, namely, phlogopites of nominal composition K(Mg3-x Alx )[Al1+x Si3-x O10 ](OH)y F2-y and lepidolites in the system trilithionite-polylithionite with composition K (Lix Al3-x )[Al4-2x Si2x O10 ](OH)y F2-y , by directly probing the aluminium distribution through 27 Al and 17 O magic-angle spinning, multiple-quantum magic-angle spinning, and 27 Al-27 Al double-quantum single-quantum nuclear magnetic resonance (NMR) experiments. Notably, 27 Al-27 Al double-quantum single-quantum magic-angle spinning NMR spectra, recorded at 9.34 and/or 20.00 T, show the spatial proximity or avoidance of the Al species inside or between the sheets. In both studied minerals, the ensemble of NMR data suggests a preference for [4] Al in the tetrahedral sheet to occupy position close to the [6] Al of the octahedral sheets.
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Affiliation(s)
- Lara Sulcek
- Institut für Geologie, Mineralogie und Geophysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Ramona Langner
- Institut für Geologie, Mineralogie und Geophysik, Ruhr-Universität Bochum, Bochum, Germany
- Department Technological Analyses and Strategic Planning, Fraunhofer-Institut für Naturwissenschaftlich-Technische Trendanalysen (INT), Euskirchen, Germany
| | - Ulrike Werner-Zwanziger
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
- Clean Technologies Research Institute, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Josef W Zwanziger
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
- Clean Technologies Research Institute, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Charlotte Martineau-Corcos
- ILV, Université de Versailles St-Quentin en Yvelines, Université Paris-Saclay, Versailles, France
- CEMHTI UPR CNRS 3079, Université d'Orléans, Orléans, France
| | - Michael Fechtelkord
- Institut für Geologie, Mineralogie und Geophysik, Ruhr-Universität Bochum, Bochum, Germany
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3
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Lamb KJ, Dowsett MR, Chatzipanagis K, Scullion ZW, Kröger R, Lee JD, Aguiar PM, North M, Parkin A. Capacitance-Assisted Sustainable Electrochemical Carbon Dioxide Mineralisation. CHEMSUSCHEM 2018; 11:137-148. [PMID: 29171724 PMCID: PMC5814831 DOI: 10.1002/cssc.201702087] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 11/16/2017] [Indexed: 06/07/2023]
Abstract
An electrochemical cell comprising a novel dual-component graphite and Earth-crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte was constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5 % carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations, which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially relevant gas stream and a solar panel as an effective zero-carbon energy source.
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Affiliation(s)
- Katie J. Lamb
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
| | | | | | | | - Roland Kröger
- Department of PhysicsUniversity of YorkYorkYO10 5DDUK
| | - James D. Lee
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
| | | | - Michael North
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
| | - Alison Parkin
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
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4
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Wildman EJ, Mclaughlin AC, Macdonald JF, Hanna JV, Skakle JMS. The Crystal Structure of Ba 3Nb 2O 8 Revisited: A Neutron Diffraction and Solid-State NMR Study. Inorg Chem 2017; 56:2653-2661. [PMID: 28186741 DOI: 10.1021/acs.inorgchem.6b02792] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The structure of Ba3Nb2O8 has been investigated using high resolution neutron powder diffraction. Our results show that, while the structure has some features in common with the 9R perovskite and palmierite structures, it is a new and distinct structure. It is shown to follow a (chh)(hhc)(chh) sequence with BaO3-δ packing layers and is a cation- and anion-deficient 9H perovskite polytype. Nb atoms occupy octahedral sites with vacancies between hexagonal close-packed layers. Isolated, corner-sharing and face-sharing Nb-O octahedra all occur within the unit cell. The identification of purely octahedral Nb is supported by solid-state 93Nb wideline NMR measurements. A two-component line shape was detected: a narrow featureless resonance with an isotropic chemical shift of δiso -928 ± 5 ppm consistent with regular Nb octahedra, and a much broader featureless resonance with an approximate isotropic chemical shift in the range δiso ∼ -944 to -937 ± 10 ppm consistent with Nb octahedra influenced by O vacancies. These are both characteristic of 6-fold oxo-coordinated Nb environments. The highly distorted octahedral environments in Ba3Nb2O8 make it a potential candidate for dielectric and photocatalytic applications.
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Affiliation(s)
- Eve J Wildman
- Department of Chemistry, School of Natural & Computing Sciences, University of Aberdeen , Meston Walk, Aberdeen AB24 3UE, U.K
| | - Abbie C Mclaughlin
- Department of Chemistry, School of Natural & Computing Sciences, University of Aberdeen , Meston Walk, Aberdeen AB24 3UE, U.K
| | - James F Macdonald
- Department of Physics, University of Warwick , Gibbet Hill Rd., Coventry CV4 7AL, U.K
| | - John V Hanna
- Department of Physics, University of Warwick , Gibbet Hill Rd., Coventry CV4 7AL, U.K
| | - Janet M S Skakle
- Department of Chemistry, School of Natural & Computing Sciences, University of Aberdeen , Meston Walk, Aberdeen AB24 3UE, U.K.,Department of Physics, School of Natural & Computing Sciences, University of Aberdeen , Meston Walk, Aberdeen AB24 3UE, U.K
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5
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Miyaji A, Kimura N, Shiga A, Hayashi Y, Nishitoba T, Motokura K, Baba T. Determination of the positions of aluminum atoms introduced into SSZ-35 and the catalytic properties of the generated Brønsted acid sites. Phys Chem Chem Phys 2017; 19:6508-6518. [DOI: 10.1039/c6cp08143f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Al atoms were introduced into three of the four possible sites with constant proportions in the zeolite SSZ-35 lattice.
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Affiliation(s)
- Akimitsu Miyaji
- Department of Environmental Chemistry and Engineering
- Interdisciplinary Graduate School of Science and Engineering
- Tokyo Institute of Technology
- Midori-ku
- Japan
| | - Nobuhiro Kimura
- Department of Environmental Chemistry and Engineering
- Interdisciplinary Graduate School of Science and Engineering
- Tokyo Institute of Technology
- Midori-ku
- Japan
| | - Akinobu Shiga
- Department of Environmental Chemistry and Engineering
- Interdisciplinary Graduate School of Science and Engineering
- Tokyo Institute of Technology
- Midori-ku
- Japan
| | - Yoshihiro Hayashi
- Department of Environmental Chemistry and Engineering
- Interdisciplinary Graduate School of Science and Engineering
- Tokyo Institute of Technology
- Midori-ku
- Japan
| | - Toshiki Nishitoba
- Department of Environmental Chemistry and Engineering
- Interdisciplinary Graduate School of Science and Engineering
- Tokyo Institute of Technology
- Midori-ku
- Japan
| | - Ken Motokura
- Department of Environmental Chemistry and Engineering
- Interdisciplinary Graduate School of Science and Engineering
- Tokyo Institute of Technology
- Midori-ku
- Japan
| | - Toshihide Baba
- Department of Environmental Chemistry and Engineering
- Interdisciplinary Graduate School of Science and Engineering
- Tokyo Institute of Technology
- Midori-ku
- Japan
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6
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Zhou B, Sun W, Zhao BC, Mi JX, Laskowski R, Terskikh V, Zhang X, Yang L, Botis SM, Sherriff BL, Pan Y. 11B MAS NMR and First-Principles Study of the [OBO3] Pyramids in Borates. Inorg Chem 2016; 55:1970-7. [DOI: 10.1021/acs.inorgchem.5b02071] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bing Zhou
- College of Materials Science and Engineering, Tongji University, Shanghai 200092, China
| | - Wei Sun
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
- Fujian Provincial Key Laboratory of Advanced Materials,
Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, Fujian China
| | - Biao-Chun Zhao
- Fujian Provincial Key Laboratory of Advanced Materials,
Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, Fujian China
| | - Jin-Xiao Mi
- Fujian Provincial Key Laboratory of Advanced Materials,
Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, Fujian China
| | - Robert Laskowski
- Institute of High Performance Computing, A*STAR, 1 Fusionopolis
Way, No. 16-16, Connexis 138632, Singapore
| | - Victor Terskikh
- Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Xi Zhang
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| | - Lingyun Yang
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| | - Sanda M. Botis
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
| | - Barbara L. Sherriff
- Department of Geological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Yuanming Pan
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
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7
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Yu Y, Edén M. Structure–composition relationships of bioactive borophosphosilicate glasses probed by multinuclear 11B, 29Si, and 31P solid state NMR. RSC Adv 2016. [DOI: 10.1039/c6ra15275a] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
By combining 11B, 29Si, and 31P nuclear magnetic resonance (NMR) experimental results, we present the first comprehensive structural investigation of 15 borophosphosilicate (BPS) glasses of the Na2O–CaO–B2O3–SiO2–P2O5 system.
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Affiliation(s)
- Yang Yu
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Stockholm University
- SE-106 91 Stockholm
- Sweden
| | - Mattias Edén
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Stockholm University
- SE-106 91 Stockholm
- Sweden
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8
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Lin Z, Jones JR, Hanna JV, Smith ME. A multinuclear solid state NMR spectroscopic study of the structural evolution of disordered calcium silicate sol–gel biomaterials. Phys Chem Chem Phys 2015; 17:2540-9. [DOI: 10.1039/c4cp04492d] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multinuclear solid state NMR, especially 17O, shows the structural evolution of calcium silicate sol–gel bioactive glasses during stabilisation and subsequent reaction with simulated body fluid.
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Affiliation(s)
- Zhongjie Lin
- Magnetic Resonance Centre, Millburn House
- Department of Physics
- University of Warwick
- Coventry
- UK
| | | | - John V. Hanna
- Magnetic Resonance Centre, Millburn House
- Department of Physics
- University of Warwick
- Coventry
- UK
| | - Mark E. Smith
- Magnetic Resonance Centre, Millburn House
- Department of Physics
- University of Warwick
- Coventry
- UK
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9
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Moura HM, Bonk FA, Vinhas RCG, Landers R, Pastore HO. Aluminium-magadiite: from crystallization studies to a multifunctional material. CrystEngComm 2011. [DOI: 10.1039/c1ce05213f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Hajjar R, Millot Y, Man PP. Phase cycling in MQMAS sequences for half-integer quadrupole spins. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2010; 57:306-342. [PMID: 20667403 DOI: 10.1016/j.pnmrs.2010.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 05/11/2010] [Indexed: 05/29/2023]
Affiliation(s)
- Redouane Hajjar
- UPMC Univ Paris 06, FRE 3230, Laboratoire RMN des Matériaux Nanoporeux, 4 Place Jussieu, F-75005 Paris, France
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11
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Hanna J, Pike K, Charpentier T, Kemp T, Smith M, Lucier B, Schurko R, Cahill L. A93Nb Solid-State NMR and Density Functional Theory Study of Four- and Six-Coordinate Niobate Systems. Chemistry 2010; 16:3222-39. [DOI: 10.1002/chem.200901581] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Gehman JD, Provis JL. Generalized biaxial shearing of MQMAS NMR spectra. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 200:167-72. [PMID: 19608445 DOI: 10.1016/j.jmr.2009.06.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 06/19/2009] [Accepted: 06/19/2009] [Indexed: 05/04/2023]
Abstract
Two dimensional multiple quantum (MQ) MAS NMR experiments have become popular due to the wide applicability of this technique to structural questions in materials science, the abundance of half-integer spin nuclei in the periodic table, and the ease of implementation on typical solid state NMR instruments. In spite of the high-resolution theoretically possible from such experiments, the homogeneous and inhomogeneous broadening factors inherent in many samples of interest can make spectral analysis challenging. We present several possible spectral shearing schemes that may be useful for spectral analysis, and in particular we introduce shearing in the directly detected dimension. We suggest that for amorphous or disordered samples that give broad spectral features, shearing may be used as a general tool for optimal positioning of these features relative to one another and for the characterization of isotropic chemical and quadrupolar shifts.
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Affiliation(s)
- John D Gehman
- School of Chemistry and Bio21 Institute, University of Melbourne, 30 Flemington Rd., Vic. 3010, Australia.
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13
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Griffith CS, Luca V, Hanna JV, Pike KJ, Smith ME, Thorogood GS. Microcrystalline Hexagonal Tungsten Bronze. 1. Basis of Ion Exchange Selectivity for Cesium and Strontium. Inorg Chem 2009; 48:5648-62. [DOI: 10.1021/ic801294x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher S. Griffith
- Australian Nuclear Science and Technology Organisation, ANSTO Minerals, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - Vittorio Luca
- Australian Nuclear Science and Technology Organisation, ANSTO Minerals, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - John V. Hanna
- Australian Nuclear Science and Technology Organisation, ANSTO Minerals, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - Kevin J. Pike
- Department of Physics, University of Warwick, Gibbet Hill Rd., Coventry CV4 7AL, United Kingdom
| | - Mark E. Smith
- Department of Physics, University of Warwick, Gibbet Hill Rd., Coventry CV4 7AL, United Kingdom
| | - Gordon S. Thorogood
- Australian Nuclear Science and Technology Organisation, ANSTO Minerals, New Illawarra Road, Lucas Heights, NSW 2234, Australia
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14
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Hajjar R, Millot Y, Man PP. NMR experimental procedure for obtaining 3Q and 5QMAS spectra from the same multiplex SPAM acquisition. CR CHIM 2008. [DOI: 10.1016/j.crci.2007.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Karpukhina NG, Werner-Zwanziger U, Zwanziger JW, Kiprianov AA. Preferential Binding of Fluorine to Aluminum in High Peralkaline Aluminosilicate Glasses. J Phys Chem B 2007; 111:10413-20. [PMID: 17691839 DOI: 10.1021/jp073687j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
For two series of fluoride-containing aluminosilicate glasses of high peralkaline type, we apply 27Al, 19F, 29Si, and 23Na NMR spectroscopy to understand the structural changes introduced by the addition of alkali fluorides. Adding fluoride in concentrations above the solubility limit causes crystallization of different phases in sodium and potassium glasses despite identical composition. However, the NMR spectra reveal that the structural evolution of the precrystallized states is similar in both series. In particular, fluorine coordinates exclusively to alkaline cations and aluminum. No indication of direct bonding with silicon was found from 19F --> 29Si cross-polarization experiments. In contrast to other glass systems, double resonance experiments in these peralkaline systems show that halide addition produces at most a minor fraction of tetrahedral aluminum containing fluorine in its coordination sphere. Instead, the fluorine addition prior to crystallization converts up to about 20% of the initial tetrahedral aluminum (1 mol % in absolute units) to 5- and 6-fold coordinated aluminum. A minor portion of five-coordinated aluminum groups is considered as the intermediate to the growing fraction of octahedral aluminum in the silicate matrix. The initialization of the crystallization process is correlated with the saturation of the silicate matrix by octahedral aluminum clusters segregating out under further doping by fluoride. It is suggested that the formation of the nonframework Al-F bonds is responsible for structural relaxation, reflected by the reduction of the glass transition temperature.
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Affiliation(s)
- N G Karpukhina
- Deparment of Chemistry and Institute for Research in Materials, Dalhousie University, Halifax, NS, Canada
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16
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Goldbourt A, Vinogradov E, Goobes G, Vega S. High resolution heteronuclear correlation NMR spectroscopy between quadrupolar nuclei and protons in the solid state. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2004; 169:342-350. [PMID: 15261632 DOI: 10.1016/j.jmr.2004.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2004] [Revised: 05/07/2004] [Indexed: 05/24/2023]
Abstract
A high resolution two-dimensional solid state NMR experiment is presented that correlates half-integer quadrupolar spins with protons. In this experiment the quadrupolar nuclei evolve during t1 under a split-t1, FAM-enhanced MQMAS pulse scheme. After each t1 period ending at the MQMAS echo position, single quantum magnetization is transferred, via a cross polarization process in the mixing time, from the quadrupolar nuclei to the protons. High-resolution proton signals are then detected in the t2 time domain during wPMLG5* homonuclear decoupling. The experiment has been demonstrated on a powder sample of sodium citrate and 23Na-1H 2D correlation spectra have been obtained. From the HETCOR spectra and the regular MQMAS spectrum, the three crystallographically inequivalent Na+ sites in the asymmetric unit were assigned. This MQMAS-wPMLG HETCOR pulse sequence can be used for spectral editing of half-integer quadrupolar nuclei coupled to protons.
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Affiliation(s)
- A Goldbourt
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot, 76100, Israel
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17
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Bräuniger T, Pike KJ, Harris RK, Madhu PK. Efficient 5QMAS NMR of spin-5/2 nuclei: use of fast amplitude-modulated radio-frequency pulses and cogwheel phase cycling. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2003; 163:64-72. [PMID: 12852908 DOI: 10.1016/s1090-7807(03)00124-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report here an efficient multiple-quantum magic-angle spinning (MQMAS) pulse sequence involving fast amplitude-modulated (FAM) radio-frequency pulses for excitation and conversion of five-quantum (5Q) coherences of spin-5/2 nuclei. The use of a FAM-I type pulse train for the conversion of 5Q into 1Q coherences proves to be easier to implement experimentally than the earlier suggested use of a FAM-II type sequence [J. Magn. Reson. 154 (2002) 280], while delivering at least equal signal enhancement. Results of numerical simulations and experimental 27Al 5QMAS spectra of aluminium acetylacetonate for different excitation and conversion schemes are compared to substantiate these claims. We also demonstrate the feasibility of acquiring 5QMAS spectra of spin-5/2 systems using cogwheel phase cycling [J. Magn. Reson. 155 (2002) 300] to select the desired coherence pathways. A cogwheel phase cycle of only 57 steps is shown to be as effective as the minimum conventional nested 77-step phase cycle.
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Affiliation(s)
- Thomas Bräuniger
- Department of Chemistry, University of Durham, DH1 3LE Durham, UK.
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18
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Grinshtein J, Frydman L. Solid state separated-local-field NMR spectroscopy on half-integer quadrupolar nuclei: principles and applications to borane analysis. J Am Chem Soc 2003; 125:7451-60. [PMID: 12797820 DOI: 10.1021/ja0214025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New multidimensional NMR methods correlating the quadrupolar and heteronuclear dipolar interactions affecting a half-integer quadrupolar spin in the solid state are introduced and exemplified. The methods extend separated-local-field magic-angle spinning (SLF MAS) NMR techniques that have been used successfully in spin-(1)/(2) spectroscopy to the study of S >/= (3)/(2) nuclei. In our implementation, these techniques avoid homonuclear proton decoupling requirements by relying on moderately fast MAS rates (6-15 kHz) and use rotor-synchronized constant-time pulse sequences to achieve nearly arbitrary amplifications of the apparent dipolar coupling strengths. The result is a suite of simple 2D NMR experiments, whose line shapes carry valuable information about the structure and dynamics of solids containing quadrupolar and proton nuclei. The potential of these sequences was exploited to gather new insight into the structure and dynamics of a variety of boron-containing samples. These experimental SLF schemes were also extended to 3D NMR experiments that incorporate multiple-quantum MAS, thus enabling the resolution needed to study multiple chemical sites in a solid and providing a useful tool for the assignment of inequivalent sites.
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Affiliation(s)
- Julia Grinshtein
- Department of Chemical Physics, Weizmann Institute of Sciences, 76100 Rehovot, Israel
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