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Leroy C, Bryce DL. Recent advances in solid-state nuclear magnetic resonance spectroscopy of exotic nuclei. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2018; 109:160-199. [PMID: 30527135 DOI: 10.1016/j.pnmrs.2018.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 07/18/2018] [Accepted: 08/10/2018] [Indexed: 06/09/2023]
Abstract
We present a review of recent advances in solid-state nuclear magnetic resonance (SSNMR) studies of exotic nuclei. Exotic nuclei may be spin-1/2 or quadrupolar, and typically have low gyromagnetic ratios, low natural abundances, large quadrupole moments (when I > 1/2), or some combination of these properties, generally resulting in low receptivities and/or prohibitively broad line widths. Some nuclides are little studied for other reasons, also rendering them somewhat exotic. We first discuss some of the recent progress in pulse sequences and hardware development which continues to enable researchers to study new kinds of materials as well as previously unfeasible nuclei. This is followed by a survey of applications to a wide range of exotic nuclei (including e.g., 9Be, 25Mg, 33S, 39K, 43Ca, 47/49Ti, 53Cr, 59Co, 61Ni, 67Zn, 73Ge, 75As, 87Sr, 115In, 119Sn, 121/123Sb, 135/137Ba, 185/187Re, 209Bi), most of them quadrupolar. The scope of the review is the past ten years, i.e., 2007-2017.
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Affiliation(s)
- César Leroy
- Department of Chemistry and Biomolecular Sciences & Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario K1N 6N5, Canada
| | - David L Bryce
- Department of Chemistry and Biomolecular Sciences & Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario K1N 6N5, Canada.
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Simpson AJ, Simpson MJ, Soong R. Environmental Nuclear Magnetic Resonance Spectroscopy: An Overview and a Primer. Anal Chem 2017; 90:628-639. [PMID: 29131590 DOI: 10.1021/acs.analchem.7b03241] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
NMR spectroscopy is a versatile tool for the study of structure and interactions in environmental media such as air, soil, and water as well as monitoring the metabolic responses of living organisms to an ever changing environment. Part review, part perspective, and part tutorial, this Feature is aimed at nonspecialists who are interested in learning more about the potential and impact of NMR spectroscopy in environmental research.
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Affiliation(s)
- André J Simpson
- Environmental NMR Centre and Department of Physical & Environmental Sciences, University of Toronto Scarborough , Toronto, Ontario, Canada , M1C 1A4
| | - Myrna J Simpson
- Environmental NMR Centre and Department of Physical & Environmental Sciences, University of Toronto Scarborough , Toronto, Ontario, Canada , M1C 1A4
| | - Ronald Soong
- Environmental NMR Centre and Department of Physical & Environmental Sciences, University of Toronto Scarborough , Toronto, Ontario, Canada , M1C 1A4
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Faucher A, Terskikh VV, Ye E, Bernard GM, Wasylishen RE. Solid-State 87Sr NMR Spectroscopy at Natural Abundance and High Magnetic Field Strength. J Phys Chem A 2015; 119:11847-61. [DOI: 10.1021/acs.jpca.5b09392] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alexandra Faucher
- Department
of Chemistry, Gunning-Lemieux Chemistry Centre, University of Alberta, Edmonton, AB, Canada T6G 2G2
| | - Victor V. Terskikh
- Department
of Chemistry, University of Ottawa, Ottawa, ON, Canada K1N 6N5
| | - Eric Ye
- Department
of Chemistry, University of Ottawa, Ottawa, ON, Canada K1N 6N5
| | - Guy M. Bernard
- Department
of Chemistry, Gunning-Lemieux Chemistry Centre, University of Alberta, Edmonton, AB, Canada T6G 2G2
| | - Roderick E. Wasylishen
- Department
of Chemistry, Gunning-Lemieux Chemistry Centre, University of Alberta, Edmonton, AB, Canada T6G 2G2
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Man PP, Bonhomme C, Babonneau F. Denoising NMR time-domain signal by singular-value decomposition accelerated by graphics processing units. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2014; 61-62:28-34. [PMID: 24880899 DOI: 10.1016/j.ssnmr.2014.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/30/2014] [Accepted: 05/08/2014] [Indexed: 06/03/2023]
Abstract
We present a post-processing method that decreases the NMR spectrum noise without line shape distortion. As a result the signal-to-noise (S/N) ratio of a spectrum increases. This method is called Cadzow enhancement procedure that is based on the singular-value decomposition of time-domain signal. We also provide software whose execution duration is a few seconds for typical data when it is executed in modern graphic-processing unit. We tested this procedure not only on low sensitive nucleus (29)Si in hybrid materials but also on low gyromagnetic ratio, quadrupole nucleus (87)Sr in reference sample Sr(NO3)2. Improving the spectrum S/N ratio facilitates the determination of T/Q ratio of hybrid materials. It is also applicable to simulated spectrum, resulting shorter simulation duration for powder averaging. An estimation of the number of singular values needed for denoising is also provided.
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Affiliation(s)
- Pascal P Man
- Sorbonne Universités, UPMC Univ Paris 06, FR 2482, Institut des matériaux de Paris-Centre, Collège de France, F-75005 Paris, France; CNRS, FR 2482, Institut des matériaux de Paris-Centre, Collège de France, F-75005 Paris, France.
| | - Christian Bonhomme
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7574, Chimie de la Matière Condensée de Paris, Collège de France, F-75005 Paris, France; CNRS, UMR 7574, Chimie de la Matière Condensée de Paris, Collège de France, F-75005 Paris, France
| | - Florence Babonneau
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7574, Chimie de la Matière Condensée de Paris, Collège de France, F-75005 Paris, France; CNRS, UMR 7574, Chimie de la Matière Condensée de Paris, Collège de France, F-75005 Paris, France
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Burgess KMN, Xu Y, Leclerc MC, Bryce DL. Alkaline-Earth Metal Carboxylates Characterized by 43Ca and 87Sr Solid-State NMR: Impact of Metal-Amine Bonding. Inorg Chem 2013; 53:552-61. [DOI: 10.1021/ic402658d] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Kevin M. N. Burgess
- Department
of Chemistry and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario, Canada K1N
6N5
| | - Yang Xu
- Department
of Chemistry and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario, Canada K1N
6N5
| | - Matthew C. Leclerc
- Department
of Chemistry and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario, Canada K1N
6N5
| | - David L. Bryce
- Department
of Chemistry and Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario, Canada K1N
6N5
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Pallister PJ, Moudrakovski IL, Enright GD, Ripmeester JA. Structural assessment of anhydrous sulfates with high field 33S solid state NMR and first principles calculations. CrystEngComm 2013. [DOI: 10.1039/c3ce41233d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Laurencin D, Smith ME. Development of (43)Ca solid state NMR spectroscopy as a probe of local structure in inorganic and molecular materials. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2013; 68:1-40. [PMID: 23398971 DOI: 10.1016/j.pnmrs.2012.05.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 05/10/2012] [Indexed: 06/01/2023]
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Bonhomme C, Gervais C, Folliet N, Pourpoint F, Coelho Diogo C, Lao J, Jallot E, Lacroix J, Nedelec JM, Iuga D, Hanna JV, Smith ME, Xiang Y, Du J, Laurencin D. 87Sr Solid-State NMR as a Structurally Sensitive Tool for the Investigation of Materials: Antiosteoporotic Pharmaceuticals and Bioactive Glasses. J Am Chem Soc 2012; 134:12611-28. [DOI: 10.1021/ja303505g] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Christian Bonhomme
- Laboratoire Chimie de la Matière
Condensée de Paris, UMR CNRS 7574, UPMC Université Paris 06, Collège de France, 11 place Marcelin
Berthelot, 75231 Paris Cedex 05, France
| | - Christel Gervais
- Laboratoire Chimie de la Matière
Condensée de Paris, UMR CNRS 7574, UPMC Université Paris 06, Collège de France, 11 place Marcelin
Berthelot, 75231 Paris Cedex 05, France
| | - Nicolas Folliet
- Laboratoire Chimie de la Matière
Condensée de Paris, UMR CNRS 7574, UPMC Université Paris 06, Collège de France, 11 place Marcelin
Berthelot, 75231 Paris Cedex 05, France
| | - Frédérique Pourpoint
- Laboratoire Chimie de la Matière
Condensée de Paris, UMR CNRS 7574, UPMC Université Paris 06, Collège de France, 11 place Marcelin
Berthelot, 75231 Paris Cedex 05, France
| | - Cristina Coelho Diogo
- IMPC, Institut des Matériaux
de Paris Centre, FR2482, UPMC Université Paris 06, Collège de France, 11 place Marcelin Berthelot,
75231 Paris Cedex 05, France
| | - Jonathan Lao
- Clermont Université, Université
Blaise Pascal, CNRS/IN2P3, Laboratoire de Physique
Corpusculaire, BP 10448, 63000 Clermont-Ferrand, France
| | - Edouard Jallot
- Clermont Université, Université
Blaise Pascal, CNRS/IN2P3, Laboratoire de Physique
Corpusculaire, BP 10448, 63000 Clermont-Ferrand, France
| | - Joséphine Lacroix
- Clermont Université, Université
Blaise Pascal, CNRS/IN2P3, Laboratoire de Physique
Corpusculaire, BP 10448, 63000 Clermont-Ferrand, France
| | - Jean-Marie Nedelec
- Clermont Université, ENSCCF, ICCF, BP 10448, F-63000 Clermont-Ferrand, France
- CNRS, UMR
6296, ICCF, F-63177 Aubière
| | - Dinu Iuga
- Department of Physics, University of Warwick, CV4 7AL Coventry, U.K
| | - John V. Hanna
- Department of Physics, University of Warwick, CV4 7AL Coventry, U.K
| | - Mark E. Smith
- Department of Physics, University of Warwick, CV4 7AL Coventry, U.K
- Vice-Chancellor’s Office,
University House, Lancaster University,
LA1 4YW, Lancaster, U.K
| | - Ye Xiang
- Department
of Materials Science and
Engineering, CASCaM, University of North Texas, Denton, Texas 76203, United States
| | - Jincheng Du
- Department
of Materials Science and
Engineering, CASCaM, University of North Texas, Denton, Texas 76203, United States
| | - Danielle Laurencin
- Institut Charles Gerhardt de Montpellier,
UMR 5253, CNRS UM2 UM1 ENSCM, CC 1701 Université de Montpellier 2, Place E. Bataillon, 34095 Montpellier
cedex 5, France
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Reinholdt M, Croissant J, Di Carlo L, Granier D, Gaveau P, Bégu S, Devoisselle JM, Mutin PH, Smith ME, Bonhomme C, Gervais C, van der Lee A, Laurencin D. Synthesis and Characterization of Crystalline Structures Based on Phenylboronate Ligands Bound to Alkaline Earth Cations. Inorg Chem 2011; 50:7802-10. [DOI: 10.1021/ic200961a] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marc Reinholdt
- Institut Charles Gerhardt Montpellier ICGM, UMR 5253 CNRS-UM2-UM1-ENSCM, Pl. E. Bataillon, CC1701, 34095 Montpellier Cedex 5, France
| | - Jonas Croissant
- Institut Charles Gerhardt Montpellier ICGM, UMR 5253 CNRS-UM2-UM1-ENSCM, Pl. E. Bataillon, CC1701, 34095 Montpellier Cedex 5, France
| | - Lidia Di Carlo
- Institut Charles Gerhardt Montpellier ICGM, UMR 5253 CNRS-UM2-UM1-ENSCM, Pl. E. Bataillon, CC1701, 34095 Montpellier Cedex 5, France
| | - Dominique Granier
- Institut Charles Gerhardt Montpellier ICGM, UMR 5253 CNRS-UM2-UM1-ENSCM, Pl. E. Bataillon, CC1701, 34095 Montpellier Cedex 5, France
| | - Philippe Gaveau
- Institut Charles Gerhardt Montpellier ICGM, UMR 5253 CNRS-UM2-UM1-ENSCM, Pl. E. Bataillon, CC1701, 34095 Montpellier Cedex 5, France
| | - Sylvie Bégu
- Institut Charles Gerhardt Montpellier ICGM, UMR 5253 CNRS-UM2-UM1-ENSCM, Pl. E. Bataillon, CC1701, 34095 Montpellier Cedex 5, France
| | - Jean-Marie Devoisselle
- Institut Charles Gerhardt Montpellier ICGM, UMR 5253 CNRS-UM2-UM1-ENSCM, Pl. E. Bataillon, CC1701, 34095 Montpellier Cedex 5, France
| | - P. Hubert Mutin
- Institut Charles Gerhardt Montpellier ICGM, UMR 5253 CNRS-UM2-UM1-ENSCM, Pl. E. Bataillon, CC1701, 34095 Montpellier Cedex 5, France
| | - Mark E. Smith
- Department of Physics, University of Warwick, CV4 7AL Coventry, United Kingdom
| | - Christian Bonhomme
- LCMCP, UMR CNRS 7574, UPMC Université Paris 06, Collège de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Christel Gervais
- LCMCP, UMR CNRS 7574, UPMC Université Paris 06, Collège de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Arie van der Lee
- Institut Européen des Membranes, CNRS - UMR 5635, Université de Montpellier 2, CC 047, Pl. E. Bataillon, 34095 Montpellier Cedex 5, France
| | - Danielle Laurencin
- Institut Charles Gerhardt Montpellier ICGM, UMR 5253 CNRS-UM2-UM1-ENSCM, Pl. E. Bataillon, CC1701, 34095 Montpellier Cedex 5, France
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MacGregor AW, O'Dell LA, Schurko RW. New methods for the acquisition of ultra-wideline solid-state NMR spectra of spin-1/2 nuclides. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 208:103-113. [PMID: 21130011 DOI: 10.1016/j.jmr.2010.10.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 10/15/2010] [Accepted: 10/16/2010] [Indexed: 05/30/2023]
Abstract
The Wideband Uniform Rate Smooth Truncation - Carr-Purcell Meiboom-Gill (WURST-CPMG) pulse sequence was recently introduced as a new method of acquiring ultra-wideline solid-state NMR (SSNMR) patterns of quadrupolar nuclei (Chem. Phys. Lett. 464 (2008) 97). Herein, we describe the application of the WURST-CPMG pulse sequence to stationary samples (i.e., non-spinning or "static" samples) of various spin-1/2 nuclides ((119)Sn, (207)Pb, (199)Hg and (195)Pt) in order to examine its effectiveness for acquiring ultra-wideline SSNMR patterns. WURST-CPMG is compared to the CPMG and Cross Polarization (CP)-CPMG pulse sequences in select cases ((119)Sn and (207)Pb, respectively), and its usefulness in obtaining ultra-wideline SSNMR spectra in a piecewise fashion is explored. In addition, a preliminary investigation of pulses generated using optimal control theory (OCT) for the purpose of wideline excitation is presented; spectra acquired using these pulses are compared with standard, rectangular pulses of similar pulse powers. Both methods show much promise for acquiring high quality wideline patterns dominated by chemical shift anisotropy, with minimal distortions and significantly reduced experimental times.
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Affiliation(s)
- Alan W MacGregor
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4
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Hamaed H, Ye E, Udachin K, Schurko RW. Solid-State 137Ba NMR Spectroscopy: An Experimental and Theoretical Investigation of 137Ba Electric Field Gradient Tensors and Their Relation to Structure and Symmetry. J Phys Chem B 2010; 114:6014-22. [DOI: 10.1021/jp102026m] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Hiyam Hamaed
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, Department of Chemistry, University of Ottawa, Ottawa, Ontario, Canada, K1N 6N5, and Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Ontario, Canada K1A 0R6
| | - Eric Ye
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, Department of Chemistry, University of Ottawa, Ottawa, Ontario, Canada, K1N 6N5, and Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Ontario, Canada K1A 0R6
| | - Konstantin Udachin
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, Department of Chemistry, University of Ottawa, Ottawa, Ontario, Canada, K1N 6N5, and Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Ontario, Canada K1A 0R6
| | - Robert W. Schurko
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, Department of Chemistry, University of Ottawa, Ottawa, Ontario, Canada, K1N 6N5, and Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Ontario, Canada K1A 0R6
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Bowers GM, Kirkpatrick RJ. High-field (75)As NMR study of arsenic oxysalts. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2007; 188:311-21. [PMID: 17761444 DOI: 10.1016/j.jmr.2007.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 07/16/2007] [Accepted: 07/17/2007] [Indexed: 05/17/2023]
Abstract
Arsenic is an important environmental hazard, but there have been few NMR investigations of its molecular scale structure and dynamics, due principally to the large quadrupole moment of (75)As and consequent large quadrupole couplings. We examine here the potential of existing, single-field solid-state NMR technology to investigate solids containing arsenate and arsenite oxyanions. The results show that current techniques have significant potential for arsenates that do not contain both protonated H(x)AsO4-(3-x) groups and structural water molecules, but that the quadrupole couplings for the arsenites examined here are large enough that interpretation of the spectra is difficult, even at 21.1T. Compounds that contain both structural H(2)O molecules and protonated arsenate groups do not yield resolvable signal, likely a result of T(2) effects related to a combination of strong quadrupolar interactions and proton exchange. Spin-echo experiments at 11.7 and 14.1T were effective for Li(3)AsO(4) and CsH(2)AsO(4), as were whole-pattern spikelet experiments for arsenate oxide (As(2)O(5)) at 17.6 and 21.1T. The central transition resonance of Ca(3)(AsO(4))(2).8H(2)O is approximately 6 MHz broad and required a non-conventional, histogram-style spikelet method at high field to improve acquisition efficiency. This approach reduces the acquisition time due to the sensitivity enhancement of the spikelet sequence and a reduction in the number of frequency increments required to map the resonance. Despite the large quadrupole couplings, we have identified a correlation between the (75)As isotropic chemical shift and the electronegativity of the next-nearest neighbor cation in arsenate compounds.
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Affiliation(s)
- Geoffrey M Bowers
- Department of Geology, University of Illinois at Urbana/Champaign, Urbana, IL 61801, USA.
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Feindel KW, Ooms KJ, Wasylishen RE. A solid-state 55Mn NMR spectroscopy and DFT investigation of manganese pentacarbonyl compounds. Phys Chem Chem Phys 2007; 9:1226-38. [PMID: 17325769 DOI: 10.1039/b616821c] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Central transition (55)Mn NMR spectra of several solid manganese pentacarbonyls acquired at magnetic field strengths of 11.75, 17.63, and 21.1 T are presented. The variety of distinct powder sample lineshapes obtained demonstrates the sensitivity of solid-state (55)Mn NMR to the local bonding environment, including the presence of crystallographically unique Mn sites, and facilitates the extraction of the Mn chemical shift anisotropies, CSAs, and the nuclear quadrupolar parameters. The compounds investigated include molecules with approximate C(4v) symmetry, LMn(CO)(5)(L = Cl, Br, I, HgMn(CO)(5), CH(3)) and several molecules of lower symmetry (L = PhCH(2), Ph(3-n)Cl(n)Sn (n= 1, 2, 3)). For these compounds, the Mn CSA values range from <100 ppm for Cl(3)SnMn(CO)(5) to 1260 ppm for ClMn(CO)(5). At 21.1 T the (55)Mn NMR lineshapes are appreciably influenced by the Mn CSA despite the presence of significant (55)Mn quadrupolar coupling constants that range from 8.0 MHz for Cl(3)SnMn(CO)(5) to 35.0 MHz for CH(3)Mn(CO)(5). The breadth of the solid-state (55)Mn NMR spectra of the pentacarbonyl halides is dominated by the CSA at all three applied magnetic fields. DFT calculations of the Mn magnetic shielding tensors reproduce the experimental trends and the magnitude of the CSA is qualitatively rationalized using a molecular orbital, MO, interpretation based on Ramsey's theory of magnetic shielding. In addition to the energy differences between symmetry-appropriate occupied and virtual MOs, the d-character of the Mn MOs is important for determining the paramagnetic shielding contribution to the principal components of the magnetic shielding tensor.
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Affiliation(s)
- Kirk W Feindel
- Department of Chemistry, University of Alberta, Edmonton, Canada AB T6G 2G2
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Bowers GM, Ravella R, Komarneni S, Mueller KT. NMR Study of Strontium Binding by a Micaceous Mineral. J Phys Chem B 2006; 110:7159-64. [PMID: 16599480 DOI: 10.1021/jp057205k] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The nature of strontium binding by soil minerals directly affects the transport and sequestration/remediation of radioactive strontium species released from leaking high-level nuclear waste storage tanks. However, the molecular-level structure of strontium binding sites has seldom been explored in phyllosilicate minerals by direct spectroscopic means and is not well-understood. In this work, we use solid-state NMR to analyze strontium directly and indirectly in a fully strontium-exchanged synthetic mica of nominal composition Na(4)Mg(6)Al(4)Si(4)O(20)F(4). Thermogravimetric analysis, X-ray diffraction analysis, and NMR evidence supports that heat treatment at 500 degrees C for 4 h fully dehydrates the mica, creating a hydrogen-free interlayer. Analysis of the strontium NMR spectrum of the heat-treated mica shows a single strontium environment with a quadrupolar coupling constant of 9.02 MHz and a quadrupolar asymmetry parameter of 1.0. These quadrupolar parameters are consistent with a highly distorted and asymmetric coordination environment that would be produced by strontium cations without water in the coordination sphere bound deep within the ditrigonal holes. Evidence for at least one additional strontium environment, where proton-strontium couplings may occur, was found via a (1)H-(87)Sr transfer of populations by double resonance NMR experiment. We conclude that the strontium cations in the proton-free interlayer are observable by (87)Sr NMR and bound through electrostatic interactions as nine coordinate inner-sphere complexes sitting in the ditrigonal holes. Partially hydrated strontium cations invisible to direct (87)Sr NMR are also present and located on the external mica surfaces, which are known to hydrate upon exposure to atmospheric moisture. These results demonstrate that modern pulsed NMR techniques and high fields can be used effectively to provide structural details of strontium binding by phyllosilicate minerals.
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Affiliation(s)
- Geoffrey M Bowers
- Department of Chemistry and Department of Crop and Soil Sciences, Penn State University, University Park, Pennsylvania 16802, USA
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