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Kanwal N, Colaux H, Dawson DM, Nishiyama Y, Ashbrook SE. Sensitivity improvement in 5QMAS NMR experiments using FAM-N pulses. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 100:1-10. [PMID: 30903912 DOI: 10.1016/j.ssnmr.2019.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/11/2019] [Accepted: 03/11/2019] [Indexed: 06/09/2023]
Abstract
The multiple-quantum magic-angle spinning (MQMAS) experiment is a popular choice for obtaining high-resolution solid-state NMR spectra of quadrupolar nuclei with half-integer spin quantum number. However, its inherently poor sensitivity limits its application in more challenging systems. In particular, the use of higher-order multiple-quantum coherences, which have the potential to provide higher resolution in the isotropic spectrum, results in a further decrease in sensitivity. Here we extend our recent work, which introduced an automated, high-throughput approach to generate amplitude-modulated composite pulses (termed FAM-N) to improve the efficiency of the conversion of three-quantum coherences, and explore the use of similar pulses in five-quantum MAS experiments. We consider three different approaches, and are able to demonstrate that all three provide good enhancements over single pulse conversion in all but the most extreme cases, and work well at a range of spinning rates. We show that FAM-N pulses are robust to variation in the quadrupolar coupling and rf nutation rate, demonstrating their applicability in multisite systems and systems where direct experimental optimisation of complex composite pulses is not feasible. This work will ease the implementation of higher-order MQMAS experiments and enable their application to materials and systems that were previously deemed too difficult to study.
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Affiliation(s)
- Nasima Kanwal
- School of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Henri Colaux
- RIKEN-JEOL Collaboration Center, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan; Center for Surface Chemistry and Catalysis, KU Leuven, 3001, Heverlee, Belgium
| | - Daniel M Dawson
- School of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Yusuke Nishiyama
- RIKEN-JEOL Collaboration Center, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan; JEOL RESONANCE Inc., Musashino, Akishima, Tokyo, 196-8558, Japan; NMR Science and Development Division, RIKEN SPring-8 Center, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan
| | - Sharon E Ashbrook
- School of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St Andrews, St Andrews, KY16 9ST, UK.
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Colaux H, Dawson DM, Ashbrook SE. Investigating FAM-N pulses for signal enhancement in MQMAS NMR of quadrupolar nuclei. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2017; 84:89-102. [PMID: 28131696 DOI: 10.1016/j.ssnmr.2017.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 01/05/2017] [Accepted: 01/10/2017] [Indexed: 06/06/2023]
Abstract
Although a popular choice for obtaining high-resolution solid-state NMR spectra of quadrupolar nuclei, the inherently low sensitivity of the multiple-quantum magic-angle spinning (MQMAS) experiment has limited its application for nuclei with low receptivity or when the available sample volume is limited. A number of methods have been introduced in the literature to attempt to address this problem. Recently, we have introduced an alternative, automated approach, based on numerical simulations, for generating amplitude-modulated pulses (termed FAM-N pulses) to enhance the efficiency of the triple- to single-quantum conversion step within MQMAS. This results in efficient pulses that can be used without experimental reoptimisation, ensuring that this method is particularly suitable for challenging nuclei and systems. In this work, we investigate the applicability of FAM-N pulses to a wider variety of systems, and their robustness under more challenging experimental conditions. These include experiments performed under fast MAS, nuclei with higher spin quantum numbers, samples with multiple distinct sites, low-γ nuclei and nuclei subject to large quadrupolar interactions.
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Affiliation(s)
- Henri Colaux
- School of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK
| | - Daniel M Dawson
- School of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK
| | - Sharon E Ashbrook
- School of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK.
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3
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Bräuniger T, Jansen M. Solid-state NMR Spectroscopy of Quadrupolar Nuclei in Inorganic Chemistry. Z Anorg Allg Chem 2013. [DOI: 10.1002/zaac.201300102] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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4
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Greer BJ, Kroeker S. Characterisation of heterogeneous molybdate and chromate phase assemblages in model nuclear waste glasses by multinuclear magnetic resonance spectroscopy. Phys Chem Chem Phys 2012; 14:7375-83. [PMID: 22532058 DOI: 10.1039/c2cp40764g] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Brandon J Greer
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada
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5
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Zhang W, Chen S, Cai S, Chen Z. Detection and characterization of intermolecular multiple-quantum coherence NMR signals of IS (I=1/2; S=3/2) spin systems. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:1051-1057. [PMID: 21216661 DOI: 10.1016/j.saa.2010.12.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 12/10/2010] [Accepted: 12/14/2010] [Indexed: 05/30/2023]
Abstract
Intermolecular multiple-quantum coherences (iMQCs) have some intrinsic properties different from conventional single-quantum coherences in solution NMR. In this paper, we extended our study to heteronuclear iMQCs in IS (I=1/2, S=3/2) spin systems. A sample of sodium chloride (NaCl) water solution was taken as an example. Heteronuclear COSY revamped by asymmetric Z-gradient echo detection (CRAZED) experiments were performed. One- and two-dimensional heteronuclear iMQC spectra were obtained. The quantum-mechanical treatment was used to deduce the signal expressions. Magic angle experiments validate that the signals are indeed from intermolecular dipolar interaction and insensitive to the imperfection of radio-frequency (RF) flip angles. Both experimental results and theoretical analysis indicate that heteronuclear CRAZED experiment allows coherence transfer from spin-3/2 nuclei to spin-1/2, and vice verse. Furthermore, the dependences of iMQC signal intensities on RF pulse flip angles follow the same rules as those for heteronuclear IS (I=1/2, S=1/2 or 1) spin systems.
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Affiliation(s)
- Wen Zhang
- Department of Physics, Fujian Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, China
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Fernandez C, Pruski M. Probing quadrupolar nuclei by solid-state NMR spectroscopy: recent advances. Top Curr Chem (Cham) 2011; 306:119-88. [PMID: 21656101 DOI: 10.1007/128_2011_141] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Solid-state nuclear magnetic resonance (NMR) of quadrupolar nuclei has recently undergone remarkable development of capabilities for obtaining structural and dynamic information at the molecular level. This review summarizes the key achievements attained during the last couple of decades in solid-state NMR of both integer spin and half-integer spin quadrupolar nuclei. We provide a concise description of the first- and second-order quadrupolar interactions, and their effect on the static and magic angle spinning (MAS) spectra. Methods are explained for efficient excitation of single- and multiple-quantum coherences, and acquisition of spectra under low- and high-resolution conditions. Most of all, we present a coherent, comparative description of the high-resolution methods for half-integer quadrupolar nuclei, including double rotation (DOR), dynamic angle spinning (DAS), multiple-quantum magic angle spinning (MQMAS), and satellite transition magic angle spinning (STMAS). Also highlighted are methods for processing and analysis of the spectra. Finally, we review methods for probing the heteronuclear and homonuclear correlations between the quadrupolar nuclei and their quadrupolar or spin-1/2 neighbors.
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7
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Eckert H, Pöttgen R. 45Sc Solid State NMR Spectroscopy - A Complementary Tool to X-ray Crystallography for Structure Determination of Intermetallic Compounds. Z Anorg Allg Chem 2010. [DOI: 10.1002/zaac.201000197] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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8
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Chandran CV, Cuny J, Gautier R, Le Pollès L, Pickard CJ, Bräuniger T. Improving sensitivity and resolution of MQMAS spectra: a 45Sc-NMR case study of scandium sulphate pentahydrate. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 203:226-235. [PMID: 20089429 DOI: 10.1016/j.jmr.2009.12.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 12/18/2009] [Accepted: 12/24/2009] [Indexed: 05/28/2023]
Abstract
To efficiently obtain multiple-quantum magic-angle spinning (MQMAS) spectra of the nuclide 45Sc (I=7/2), we have combined several previously suggested techniques to enhance the signal-to-noise ratio and to improve spectral resolution for the test sample, scandium sulphate pentahydrate (ScSPH). Whereas the 45Sc-3QMAS spectrum of ScSPH does not offer sufficient resolution to clearly distinguish between the 3 scandium sites present in the crystal structure, these sites are well-resolved in the 5QMAS spectrum. The loss of sensitivity incurred by using MQMAS with 5Q coherence order is partly compensated for by using fast-amplitude modulated (FAM) sequences to improve the efficiency of both 5Q coherence excitation and conversion. Also, heteronuclear decoupling is employed to minimise dephasing of the 45Sc signal during the 5Q evolution period due to dipolar couplings with the water protons in the ScSPH sample. Application of multi-pulse decoupling schemes such as TPPM and SPINAL results in improved sensitivity and resolution in the F(1) (isotropic) dimension of the 5QMAS spectrum, the best results being achieved with the recently suggested SW(f)-TPPM sequence. By numerical fitting of the 45Sc-NMR spectra of ScSPH from 3QMAS, 5QMAS and single-quantum MAS at magnetic fields B(0)=9.4 T and 17.6 T, the isotropic chemical shift delta(iso), the quadrupolar coupling constant chi, and the asymmetry parameter eta were obtained. Averaging over all experiments, the NMR parameters determined for the 3 scandium sites, designated (a), (b) and (c) are: delta(iso)(a)=-15.5+/-0.5 ppm, chi(a)=5.60+/-0.10 MHz, eta(a)=0.06+/-0.05; delta(iso)(b)=-12.9+/-0.5 ppm, chi(b)=4.50+/-0.10 MHz, eta(b)=1.00+/-0.00; and delta(iso)(c)=-4.7+/-0.2 ppm, chi(c)=4.55+/-0.05 MHz, eta(c)=0.50+/-0.02. The NMR scandium species were assigned to the independent crystallographic sites by evaluating their experimental response to proton decoupling, and by density functional theory (DFT) calculations using the PAW and GIPAW approaches, in the following way: Sc(1) to (c), Sc(2) to (a), and Sc(3) to (b). The need to compute NMR parameters using an energy-optimised crystal structure is once again demonstrated.
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Affiliation(s)
- C Vinod Chandran
- Max-Planck-Institute of Solid-State Research, Heisenbergstr. 1, D-70569 Stuttgart, Germany
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9
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Gerothanassis IP. Oxygen-17 NMR spectroscopy: basic principles and applications (part I). PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2010; 56:95-197. [PMID: 20633350 DOI: 10.1016/j.pnmrs.2009.09.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 09/24/2009] [Indexed: 05/29/2023]
Affiliation(s)
- Ioannis P Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-451 10, Greece.
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10
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Combining STMAS and CRAMPS NMR spectroscopy: High-resolution HETCOR NMR spectra of quadrupolar and 1H nuclei in solids. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.01.053] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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11
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Amoureux JP, Trébosc J, Delevoye L, Lafon O, Hu B, Wang Q. Correlation NMR spectroscopy involving quadrupolar nuclei. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2009; 35:12-18. [PMID: 19131216 DOI: 10.1016/j.ssnmr.2008.11.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Accepted: 11/07/2008] [Indexed: 05/27/2023]
Abstract
We review the recent developments proposed for integer or half-integer quadrupolar nuclei, focussing on the methods to observe them under high-resolution and to analyze their through-space and through-bond connectivities.
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Affiliation(s)
- J P Amoureux
- UCCS, CNRS-8181, Lille-University, Villeneuve d'Ascq, Fr-59652, France.
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12
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Hung I, Uldry AC, Becker-Baldus J, Webber AL, Wong A, Smith ME, Joyce SA, Yates JR, Pickard CJ, Dupree R, Brown SP. Probing Heteronuclear 15N−17O and 13C−17O Connectivities and Proximities by Solid-State NMR Spectroscopy. J Am Chem Soc 2009; 131:1820-34. [DOI: 10.1021/ja805898d] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Ivan Hung
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
| | - Anne-Christine Uldry
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
| | - Johanna Becker-Baldus
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
| | - Amy L. Webber
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
| | - Alan Wong
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
| | - Mark E. Smith
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
| | - Siân A. Joyce
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
| | - Jonathan R. Yates
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
| | - Chris J. Pickard
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
| | - Ray Dupree
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
| | - Steven P. Brown
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K., School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, U.K., Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland, and TCM Group, Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge CB3 OHE, U.K
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Ashbrook SE, Wimperis S. Spin-locking of half-integer quadrupolar nuclei in nuclear magnetic resonance of solids: Second-order quadrupolar and resonance offset effects. J Chem Phys 2009; 131:194509. [DOI: 10.1063/1.3263904] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Thrippleton MJ, Ball TJ, Wimperis S. Satellite transitions acquired in real time by magic angle spinning (STARTMAS): ‘‘Ultrafast’’ high-resolution MAS NMR spectroscopy of spin I=3∕2 nuclei. J Chem Phys 2008; 128:034507. [DOI: 10.1063/1.2813892] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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STARTMAS: A MAS-based method for acquiring isotropic NMR spectra of spin I=3/2 nuclei in real time. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.09.075] [Citation(s) in RCA: 13] [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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16
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Ashbrook SE, Wimperis S. Spin-locking of half-integer quadrupolar nuclei in nuclear magnetic resonance of solids: creation and evolution of coherences. J Chem Phys 2006; 120:2719-31. [PMID: 15268416 DOI: 10.1063/1.1638995] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Spin-locking of half-integer quadrupolar nuclei, such as 23Na (I=3/2) and 27Al (I=5/2), is of renewed interest owing to the development of variants of the multiple-quantum and satellite-transition magic angle spinning (MAS) nuclear magnetic resonance experiments that either utilize spin-locking directly or offer the possibility that spin-locked states may arise. However, the large magnitude and, under MAS, the time dependence of the quadrupolar interaction often result in complex spin-locking phenomena that are not widely understood. Here we show that, following the application of a spin-locking pulse, a variety of coherence transfer processes occur on a time scale of approximately 1/omegaQ before the spin system settles down into a spin-locked state which may itself be time dependent if MAS is performed. We show theoretically for both spin I=3/2 and 5/2 nuclei that the spin-locked state created by this initial rapid dephasing typically consists of a variety of single- and multiple-quantum coherences and nonequilibrium population states and we discuss the subsequent evolution of these under MAS. In contrast to previous work, we consider spin-locking using a wide range of radio frequency field strengths, i.e., a range that covers both the "strong-field" (omega1 >> omegaQPAS and "weak-field" (omega1 << omegaQPAS limits. Single- and multiple-quantum filtered spin-locking experiments on NaNO2, NaNO3, and Al(acac)3, under both static and MAS conditions, are used to illustrate and confirm the results of the theoretical discussion.
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Affiliation(s)
- Sharon E Ashbrook
- Department of Chemistry, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
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17
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Ashbrook SE, Smith ME. Solid state17O NMR—an introduction to the background principles and applications to inorganic materials. Chem Soc Rev 2006; 35:718-35. [PMID: 16862272 DOI: 10.1039/b514051j] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oxygen is a key chemical element and solid state NMR can provide unique insight into the its local environment. In the last decade there have been significant advances (sensitivity, resolution) in the NMR methodology for non-integer spin quadrupole nuclei such as oxygen and the background to these techniques is presented in this tutorial review. The information that the NMR parameters can provide about the local environment is explained through a series of illustrations from different areas of solid state chemistry and structural science of inorganic materials.
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Affiliation(s)
- Sharon E Ashbrook
- School of Chemistry, University of St Andrews and EaStCHEM, St Andrews, Fife, KY16 9ST, UK
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18
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d'Espinose de Lacaillerie JB, Jarry B, Pascui O, Reichert D. "Cooking the sample": radiofrequency induced heating during solid-state NMR experiments. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2005; 28:225-32. [PMID: 16221542 DOI: 10.1016/j.ssnmr.2005.09.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Indexed: 05/04/2023]
Abstract
Dissipation of radiofrequency (RF) energy as heat during continuous wave decoupling in solid-state NMR experiment was examined outside the conventional realm of such phenomena. A significant temperature increase could occur while performing dynamic NMR measurements provided the sample contains polar molecules and the sequence calls for relatively long applications of RF power. It was shown that the methyl flip motion in dimethylsulfone (DMS) is activated by the decoupling RF energy conversion to heat during a CODEX pulse sequence. This introduced a significant bias in the correlation time-temperature dependency measurement used to obtain the activation energy of the motion. By investigating the dependency of the temperature increase in hydrated lead nitrate on experimental parameters during high-power decoupling one-pulse experiments, the mechanisms for the RF energy deposition was identified. The samples were heated due to dissipation of the energy absorbed by dielectric losses, a phenomenon commonly known as "microwave" heating. It was thus established that during solid-state NMR experiments at moderate B0 fields, RF heating could lead to the heating of samples containing polar molecules such as hydrated polymers and inorganic solids. In particular, this could result in systematic errors for slow dynamics measurements by solid-state NMR.
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Affiliation(s)
- Jean-Baptiste d'Espinose de Lacaillerie
- Laboratoire de Physique Quantique, UMR CNRS 7142 SIEN, Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, 10 rue Vauquelin, 75231 Paris, Cedex 05, France.
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19
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Kimura H, Kanesaka S, Kuroki S, Ando I, Asano A, Kurosu H. Structural characterization of poly(diethylsiloxane) in the crystalline, liquid crystalline and isotropic phases by solid-state 17O NMR spectroscopy and ab initio MO calculations. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2005; 43:209-216. [PMID: 15593344 DOI: 10.1002/mrc.1527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The structure of poly(diethylsiloxane) (PDES) has been characterized using solid-state NMR of (17)O. The sample studied had a weight-average molecular weight of 2.45 x 10(5). The sample was prepared by utilizing the cationic ring-opening polymerization of (17)O-enriched hexacyclotrisiloxane. Solid-state NMR of (17)O-enriched PDES was measured on the low-temperature beta(1) phase, the high-temperature beta(2) phase, the two-phase system consisting of the liquid crystal and isotropic liquid phase and the isotropic phase. From these data, the molecular structure and dynamics of PDES in the various phases were characterized via the chemical shifts of (17)O, and electric field gradient parameters were determined from NMR and ab initio molecular orbital (MO) calculations. In addition to the solid-state NMR of (1)H, (13)C and (29)Si previously reported on these samples, knowledge of the dynamic behavior of PDES as inferred from the NMR of (17)O in the present study was enhanced significantly. Further, the potential of combining the experimental NMR of (17)O with ab initio MO calculations to characterize the dynamics of polymers containing oxygen is demonstrated.
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Affiliation(s)
- Hideaki Kimura
- Department of Chemistry and Materials Science, International Research Center of Macromolecular Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
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20
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Lemaître V, Smith ME, Watts A. A review of oxygen-17 solid-state NMR of organic materials--towards biological applications. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2004; 26:215-235. [PMID: 15388187 DOI: 10.1016/j.ssnmr.2004.04.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2004] [Revised: 03/31/2004] [Indexed: 05/24/2023]
Abstract
17O solid state NMR of organic materials is developing rapidly. This article provides a snapshot of the current state of development of this field. The NMR techniques and enrichment protocols that are driving this progress are outlined. The (17)O parameters derived from solid-state NMR experiments are summarized and the structural sensitivity of the approach to effects such as hydrogen bonding highlighted. The prospects and challenges for (17)O solid-state NMR of biomolecules are discussed.
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Affiliation(s)
- V Lemaître
- Biomembrane Structure Unit, Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, UK
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Ashbrook SE, Farnan I. Solid-state 17O nuclear magnetic resonance spectroscopy without isotopic enrichment: direct detection of bridging oxygen in radiation damaged zircon. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2004; 26:105-12. [PMID: 15276641 DOI: 10.1016/j.ssnmr.2004.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2004] [Indexed: 05/14/2023]
Abstract
Protocols are presented for obtaining natural abundance (17)O magic angle spinning and static NMR spectra in the solid state. Rotor-assisted population transfer (RAPT), Carr-Purcell-Meiboom-Gill (CPMG) echo trains and cross-polarisation (CP) are all used to obtain spectra of sites with large as well as small electric field gradients in proton and non-proton containing inorganic materials. Spectra are of sufficient quality to obtain the typical NMR parameters by standard fitting of the spectra. The protocol is then applied to identifying the changes that accompany radioactive decay in zircon (ZrSiO(4)) where enrichment is impossible. The (17)O NMR spectra of a partially metamict zircon sample clearly show evidence of bridging oxygens being produced as a consequence of radiation damage. The spectra have been acquired at moderate magnetic fields over periods typically of 60 h (1 weekend) and it is concluded that a 'routine' overnight (17)O experiment of 15 h at high field (e.g. 21 T) may well be possible.
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Affiliation(s)
- Sharon E Ashbrook
- Department of Earth Sciences, Mineral Sciences Group, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
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Liu Z, Deng F, Ding S. Effects of pulse strength, width, and sample spinning speed on the spectral spin diffusion of multiquantum coherences of spin-32 quadrupolar nuclei. J Chem Phys 2004; 120:740-8. [PMID: 15267909 DOI: 10.1063/1.1630569] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The effects of radio-frequency pulse strength, width, and sample spinning speed on the spin-diffusion spectrum of half-integer quadrupolar spins in solids have been studied by theoretical, numerical, and experimental investigations. It is revealed that the line shape of the cross peaks changes nonmonotonically with respect to the change of pulse strength, pulse width, or sample spinning speed. It is also found that the sample spinning speed has much more pronounced influence on the spin diffusion spectral line shape. In many cases of practical importance, the effect of sample spinning must be included in spectral analysis, in contrast to the practice of previous studies. Moreover, this effect can be exploited to further improve the precision in the determination of relative orientation of the electric-field gradient tensors of the exchange partners.
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Affiliation(s)
- Zhihong Liu
- Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
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AMOUREUX JP, PRUSKI M. Theoretical and experimental assessment of single- and multiple-quantum cross-polarization in solid state NMR. Mol Phys 2002. [DOI: 10.1080/00268970210125755] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Amoureux JP, Huguenard C, Engelke F, Taulelle F. Unified representation of MQMAS and STMAS NMR of half-integer quadrupolar nuclei. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(02)00398-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Millot Y, Man PP. Procedures for labeling the high-resolution axis of two-dimensional MQ-MAS NMR spectra of half-integer quadrupole spins. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2002; 21:21-43. [PMID: 11949815 DOI: 10.1006/snmr.2001.0043] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The increasing development and application of the multiple-quantum MAS NMR for half-integer quadrupole spins has led to various RF pulse sequences for improving the excitation of multiple-quantum coherences and their conversion to single-quantum coherences. As a result, several conventions for labeling the Fl dimension of a 2D MQ-MAS spectrum appear in the literature. The corresponding relations for extracting the isotropic chemical shift, the quadrupole coupling constant, and the asymmetry parameter from experimental data are not always provided. We analyze these various conventions systematically and propose a new one, similar to that introduced by J.-P. Amoureux and C. Fernandez (2000, Solid State NMR 10, 339-343). These various conventions are illustrated with 27Al (I = 5/2) nuclei in aluminum acetylacetonate Al(CH3COCHCOCH3)3. Another experimental problem often met, the aliasing of peaks in the 2D spectrum, is analyzed and illustrated with 27Al (I = 5/2) in NH4Y zeolite and 23Na (I = 3/2) in sodium pyrophosphate Na4P2O7.
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Affiliation(s)
- Yannick Millot
- Systèmes Interfaciaux a l'Echelle Nanométrique, CNRS FRE 2312, Laboratoire de Chimie des Surfaces, Université Pierre et Marie Curie, Paris, France
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26
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Lupulescu A, Brown SP, Spiess HW. Rotor-encoded heteronuclear MQ MAS NMR spectroscopy of half-integer quadrupolar and spin I=1/2 nuclei. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2002; 154:101-129. [PMID: 11820831 DOI: 10.1006/jmre.2001.2464] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A new two-dimensional heteronuclear multiple-quantum magic-angle spinning (MQ MAS) experiment is presented which combines high resolution for the half-integer quadrupolar nucleus with information about the dipolar coupling between the quadrupolar nucleus and a spin I=1/2 nucleus. Homonuclear MQ coherence is initially created for the half-integer quadrupolar nucleus by a single pulse as in a standard MQ MAS experiment. REDOR recoupling of the heteronuclear dipolar coupling then allows the creation of a heteronuclear multiple-quantum coherence comprising multiple- and single-quantum coherence of the quadrupolar and spin I=1/2 nucleus, respectively, which evolves during t1. Provided that the t1 increment is not rotor synchronized, rotor-encoded spinning-sideband patterns are observed in the indirect dimension. Simulated spectra for an isolated IS spin pair show that these patterns depend on the recoupling time, the magnitude of the dipolar coupling, the quadrupolar parameters, as well as the relative orientation of the quadrupolar and dipolar principal axes systems. Spectra are presented for Na2HPO4, with the heteronuclear 23Na-1HMQ MAS experiments beginning with the excitation of 23Na (spin I=3/2) three-quantum coherence. Coherence counting experiments demonstrate that four- and two-quantum coherences evolve during t1. The heteronuclear spinning-sideband patterns observed for the three-spin H-Na-H system associated with the Na(2) site are analyzed. For an IS2 system, simulated spectra show that, considering the free parameters, the spinning-sideband patterns are particularly sensitive to only, first, the angle between the two IS internuclear vectors and, second, the two heteronuclear dipolar couplings. It is demonstrated that the proton localization around the Na(2) site according to the literature crystal structure of Na2HPO4 is erroneous. Instead, the experimental data is consistent with two alternative different structural arrangements, whereby either there is a deviation of 10 degrees from linearity for the case of two identical Na-H distances, or there is a linear arrangement, but the two Na-H distances are different. Furthermore, the question of the origin of spinning-sidebands in the (homonuclear) MQ MAS experiment is revisited. It is shown that the asymmetric experimental MQ sideband pattern observed for the low-C(Q) Na(2) site in Na(2)HPO4 can only be explained by considering the 23Na chemical shift anisotropy.
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Affiliation(s)
- Adonis Lupulescu
- Max-Planck-Institut für Polymerforschung, D-55021 Mainz, Germany
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27
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NMR—crystallographic studies of aluminophosphate A1PO4-40. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0167-2991(02)80369-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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28
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Ashbrook SE, Wimperis S. Novel two-dimensional NMR methods that combine single-quantum cross-polarization and multiple-quantum MAS of quadrupolar nuclei. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)00453-5] [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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