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Li Y, Trébosc J, Hu B, Shen M, Amoureux JP, Lafon O. Indirect detection of broad spectra in solid-state NMR using interleaved DANTE trains. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 294:101-114. [PMID: 30032034 DOI: 10.1016/j.jmr.2018.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 07/03/2018] [Accepted: 07/07/2018] [Indexed: 06/08/2023]
Abstract
We analyze the performances and the optimization of 1H-{I} HMQC experiments using basic and interleaved DANTE schemes for the indirect detection of nuclei I = 1/2 or 1 exhibiting wide lines dominated by chemical shift anisotropy (CSA) or quadrupole interaction, respectively. These sequences are first described using average Hamiltonian theory. Then, we analyze using numerical simulations (i) the optimal lengths of the DANTE train and the individual pulses, (ii) the robustness of these experiments to offset, and (iii) the optimal choice of the defocusing and refocusing times for both 1H-{I} J- and D-HMQC sequences for 195Pt (I = 1/2) and 14N (I = 1) nuclei subject to large CSA and quadrupole interaction, respectively. These simulations are compared to 1H-{14N} D-HMQC experiments on γ-glycine and L-histidine.HCl at B0 = 18.8 T and MAS frequency of 62.5 kHz. The present study shows that (i) the optimal defocusing and refocusing times do not depend on the chosen DANTE scheme, (ii) the DANTE trains must be applied with the highest rf-field compatible with the probe specifications and the stability of the sample, (iii) the excitation bandwidth along the indirect dimension of HMQC sequence using DANTE trains is inversely proportional to their length, (iv) interleaved DANTE trains increase the excitation bandwidth of these sequences, and (v) dephasing under residual 1H-1H and 1H-I dipolar couplings, as well as 14N second-order quadrupole interaction, during the length of the DANTE scheme attenuate the transfer efficiency.
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Affiliation(s)
- Yixuan Li
- Univ. Lille, CNRS, UMR 8181-UCCS, Unité de Catalyse et de Chimie du Solide, F-59000 Lille, France; Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Materials Science, East China Normal University, Shanghai 200062, China
| | - Julien Trébosc
- Univ. Lille, CNRS, UMR 8181-UCCS, Unité de Catalyse et de Chimie du Solide, F-59000 Lille, France
| | - Bingwen Hu
- Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Materials Science, East China Normal University, Shanghai 200062, China
| | - Ming Shen
- Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Materials Science, East China Normal University, Shanghai 200062, China
| | - Jean-Paul Amoureux
- Univ. Lille, CNRS, UMR 8181-UCCS, Unité de Catalyse et de Chimie du Solide, F-59000 Lille, France; Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Materials Science, East China Normal University, Shanghai 200062, China; Bruker France, 34 rue de l'Industrie, F-67166 Wissembourg, France.
| | - Olivier Lafon
- Univ. Lille, CNRS, UMR 8181-UCCS, Unité de Catalyse et de Chimie du Solide, F-59000 Lille, France; Institut Universitaire de France, 1, rue Descartes, 75231 Paris, France.
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Carnevale D, Ji X, Bodenhausen G. Double cross polarization for the indirect detection of nitrogen-14 nuclei in magic angle spinning NMR spectroscopy. J Chem Phys 2018; 147:184201. [PMID: 29141439 DOI: 10.1063/1.5000689] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Nitrogen-14 NMR spectra at fast magic-angle spinning rates can be acquired indirectly by means of two-dimensional techniques based on double cross polarization transfer 1H → 14N →1H. Experimental evidence is given for polycrystalline samples of glycine, l-histidine, and the dipeptide Ala-Gly. Either one-bond or long-range correlations can be favored by choosing the length of the cross polarization contact pulses. Longer contact pulses allow the detection of unprotonated nitrogen sites. In contrast to earlier methods that exploited second-order quadrupolar/dipolar cross-terms, cross polarization operates in the manner of the method of Hartmann and Hahn, even for 14N quadrupolar couplings up to 4 MHz. Simulations explain why amorphous samples tend to give rise to featureless spectra because the 14N quadrupolar interactions may vary dramatically with the lattice environment. The experiments are straightforward to set up and are shown to be effective for different nitrogen environments and robust with respect to the rf-field strengths and to the 14N carrier frequency during cross polarization. The efficiency of indirect detection of 14N nuclei by double cross polarization is shown to be similar to that of isotopically enriched 13C nuclei.
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Affiliation(s)
- Diego Carnevale
- Departement de Chimie, Ecole Normale Superieure, PSL Research University, UPMC Université Paris 06, CNRS, Laboratoire des Biomolecules (LBM), 24 rue Lhomond, 75005 Paris, France
| | - Xiao Ji
- Departement de Chimie, Ecole Normale Superieure, PSL Research University, UPMC Université Paris 06, CNRS, Laboratoire des Biomolecules (LBM), 24 rue Lhomond, 75005 Paris, France
| | - Geoffrey Bodenhausen
- Departement de Chimie, Ecole Normale Superieure, PSL Research University, UPMC Université Paris 06, CNRS, Laboratoire des Biomolecules (LBM), 24 rue Lhomond, 75005 Paris, France
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Shen M, Trébosc J, O'Dell LA, Lafon O, Pourpoint F, Hu B, Chen Q, Amoureux JP. Comparison of various NMR methods for the indirect detection of nitrogen-14 nuclei via protons in solids. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 258:86-95. [PMID: 26232366 DOI: 10.1016/j.jmr.2015.06.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/11/2015] [Accepted: 06/18/2015] [Indexed: 06/04/2023]
Abstract
We present an experimental comparison of several through-space Hetero-nuclear Multiple-Quantum Correlation experiments, which allow the indirect observation of homo-nuclear single- (SQ) or double-quantum (DQ) (14)N coherences via spy (1)H nuclei. These (1)H-{(14)N} D-HMQC sequences differ not only by the order of (14)N coherences evolving during the indirect evolution, t1, but also by the radio-frequency (rf) scheme used to excite and reconvert these coherences under Magic-Angle Spinning (MAS). Here, the SQ coherences are created by the application of center-band frequency-selective pulses, i.e. long and low-power rectangular pulses at the (14)N Larmor frequency, ν0((14)N), whereas the DQ coherences are excited and reconverted using rf irradiation either at ν0((14)N) or at the (14)N overtone frequency, 2ν0((14)N). The overtone excitation is achieved either by constant frequency rectangular pulses or by frequency-swept pulses, specifically Wide-band, Uniform-Rate, and Smooth-Truncation (WURST) pulse shapes. The present article compares the performances of four different (1)H-{(14)N} D-HMQC sequences, including those with (14)N rectangular pulses at ν0((14)N) for the indirect detection of homo-nuclear (i) (14)N SQ or (ii) DQ coherences, as well as their overtone variants using (iii) rectangular or (iv) WURST pulses. The compared properties include: (i) the sensitivity, (ii) the spectral resolution in the (14)N dimension, (iii) the rf requirements (power and pulse length), as well as the robustness to (iv) rf offset and (v) MAS frequency instabilities. Such experimental comparisons are carried out for γ-glycine and l-histidine.HCl monohydrate, which contain (14)N sites subject to moderate quadrupole interactions. We demonstrate that the optimum choice of the (1)H-{(14)N} D-HMQC method depends on the experimental goal. When the sensitivity and/or the robustness to offset are the major concerns, the D-HMQC sequence allowing the indirect detection of (14)N SQ coherences should be employed. Conversely, when the highest resolution and/or adjusted indirect spectral width are needed, overtone experiments are the method of choice. The overtone scheme using WURST pulses results in broader excitation bandwidths than that using rectangular pulses, at the expense of reduced sensitivity. Numerically exact simulations also show that the sensitivity of the overtone (1)H-{(14)N} D-HMQC experiment increases for larger quadrupole interactions.
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Affiliation(s)
- Ming Shen
- UCCS, CNRS UMR 8181, Univ. Lille, Villeneuve d'Ascq 59652, France; Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| | - Julien Trébosc
- UCCS, CNRS UMR 8181, Univ. Lille, Villeneuve d'Ascq 59652, France
| | - Luke A O'Dell
- Institute for Frontier Materials, Deakin University, Waurn Ponds Campus, Geelong, Victoria 3220, Australia
| | - Olivier Lafon
- UCCS, CNRS UMR 8181, Univ. Lille, Villeneuve d'Ascq 59652, France.
| | | | - Bingwen Hu
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| | - Qun Chen
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| | - Jean-Paul Amoureux
- UCCS, CNRS UMR 8181, Univ. Lille, Villeneuve d'Ascq 59652, France; Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China.
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Rossini AJ, Emsley L, O'Dell LA. Dynamic nuclear polarisation enhanced14N overtone MAS NMR spectroscopy. Phys Chem Chem Phys 2014; 16:12890-9. [DOI: 10.1039/c4cp00590b] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamic nuclear polarisation has been used to obtain solid-state14N overtone NMR spectra with signal enhancement levels of over two orders of magnitude, including natural abundance C–N and H–N correlation spectra.
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Affiliation(s)
- Aaron J. Rossini
- Centre de RMN à Trés Hauts Champs
- Institut de Sciences Analytiques
- Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1)
- 69100 Villeurbanne, France
| | - Lyndon Emsley
- Centre de RMN à Trés Hauts Champs
- Institut de Sciences Analytiques
- Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1)
- 69100 Villeurbanne, France
| | - Luke A. O'Dell
- Institute for Frontier Materials
- Deakin University
- Geelong, Australia
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Cavadini S. Indirect detection of nitrogen-14 in solid-state NMR spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2010; 56:46-77. [PMID: 20633348 DOI: 10.1016/j.pnmrs.2009.08.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Accepted: 08/12/2009] [Indexed: 05/29/2023]
Affiliation(s)
- Simone Cavadini
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Batochime, Lausanne, Switzerland.
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Cavadini S, Antonijevic S, Lupulescu A, Bodenhausen G. Indirect Detection of Nitrogen-14 in Solid-State NMR Spectroscopy. Chemphyschem 2007; 8:1363-74. [PMID: 17503424 DOI: 10.1002/cphc.200700049] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
NMR spectra of (14)N (spin I=1) are obtained by indirect detection in powders spinning at the magic angle. The method relies on the transfer of coherence from a neighboring "spy" nucleus with S=1/2, such as (13)C or (1)H, to single- or double-quantum transitions of (14)N nuclei. The transfer of coherence can occur through a combination of scalar and residual dipolar splittings (RDS); the latter are also known as second-order quadrupole-dipole cross terms. The two-dimensional NMR spectra reveal powder patterns determined by second- and third-order quadrupolar couplings. These spectra depend on the quadrupolar coupling constant C(Q) (typically a few megahertz), on the asymmetry parameter eta(Q) of the (14)N nucleus, and on the orientation of the internuclear vector r(IS) between the I ((14)N) and S (spy) nuclei with respect to the quadrupolar tensor. These parameters, which can be subject to motional averaging, can reveal valuable information about the structure and dynamics of nitrogen-containing solids. Application of this technique to various amino acids, either enriched in (13)C or with natural carbon isotope abundance, with spectra recorded at various magnetic fields, illustrates the scope of the method.
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Affiliation(s)
- Simone Cavadini
- Laboratoire de Résonance Magnétique Biomoléculaire, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Batochime, 1015 Lausanne, Switzerland.
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Munowitz M, Pines A. Principles and Applications of Multiple-Quantum Nmr. ADVANCES IN CHEMICAL PHYSICS 2007. [DOI: 10.1002/9780470142929.ch1] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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Cavadini S, Antonijevic S, Lupulescu A, Bodenhausen G. Indirect detection of nitrogen-14 in solids via protons by nuclear magnetic resonance spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2006; 182:168-72. [PMID: 16807019 DOI: 10.1016/j.jmr.2006.06.003] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2006] [Revised: 06/01/2006] [Accepted: 06/04/2006] [Indexed: 05/10/2023]
Abstract
This Communication describes the indirect detection of 14N nuclei (spin I=1) in solids by nuclear magnetic resonance (NMR) spectroscopy. The two-dimensional correlation method used here is closely related to the heteronuclear multiple quantum correlation (HMQC) experiment introduced in 1979 to study molecules in liquids, which has recently been used to study solids spinning at the magic angle. The difference is that the coherence transfer from neighboring 1H nuclei to 14N is achieved via a combination of J couplings and residual dipolar splittings (RDS). Projections of the two-dimensional correlation spectra onto the 14N dimension yield powder patterns which reflect the 14N quadrupolar interaction. In contrast to the indirect detection of 14N via 13C nuclei that was recently demonstrated [Gan, J. Am. Chem. Soc. 128 (2006) 6040; Cavadini et. al., J. Am. Chem. Soc., 128 (2006) 7706], this approach may benefit from enhanced sensitivity, and does not require isotopic enrichment in 13C, although the 1H line-widths may have to be reduced upon selective deuteration.
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Affiliation(s)
- Simone Cavadini
- Laboratoire de Résonance Magnétique Biomoléculaire, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Batochime, CH-1015 Lausanne, Switzerland
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Cavadini S, Lupulescu A, Antonijevic S, Bodenhausen G. Nitrogen-14 NMR Spectroscopy Using Residual Dipolar Splittings in Solids. J Am Chem Soc 2006; 128:7706-7. [PMID: 16771462 DOI: 10.1021/ja0618898] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It is shown that nuclear magnetic resonance (NMR) spectra of nitrogen-14 (spin I = 1) can be obtained by indirect detection in powders spinning at the magic angle (MAS). The method relies on the transfer of coherence from a neighboring nucleus with S = 1/2, such as carbon-13, to single- or double-quantum transitions of nitrogen-14 nuclei. The transfer of coherence occurs through second-order quadrupole-dipole cross terms, also known as residual dipolar splittings. The two-dimensional NMR spectra reveal powder patterns determined by the second-order quadrupolar interactions of nitrogen-14. Analysis of the spectra yields the quadrupolar coupling constant, CQ, and asymmetry parameter, etaQ, of nitrogen-14. These parameters can be related to the structure of nitrogen-containing solids.
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Affiliation(s)
- Simone Cavadini
- Laboratoire de Résonance Magnétique Biomoléculaire, Ecole Polytechnique Fédérale de Lausanne, Batochime, CH-1015 Lausanne, Switzerland
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Khitrin AK, Fung BM. Indirect NMR detection in solids with multiple cross-polarization periods. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2001; 152:185-188. [PMID: 11531378 DOI: 10.1006/jmre.2001.2388] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The use of indirect detection for signal enhancement in solids is much less common than in liquids, but has attracted renewed interest recently. In this work we describe an indirect detection scheme that offers a large signal enhancement for rare spins in solids. The method uses multiple periods of cross polarization, each followed by an evolution period. The latter is increased stepwise in a pseudo 2D experiment, in which the signal of the rare spin is detected as modulation of the abundant spin. As an illustration of this method, the natural abundance deuterium NMR spectrum of a static powder sample of 1,2,4,5-tetramethylbenzene is presented.
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Affiliation(s)
- A K Khitrin
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019-0370, USA
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Ashbrook SE, Wimperis S. Multiple-quantum cross-polarization and two-dimensional MQMAS NMR of quadrupolar nuclei. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2000; 147:238-249. [PMID: 11097815 DOI: 10.1006/jmre.2000.2174] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cross-polarization from (1)H to the multiple-quantum coherences of a quadrupolar nucleus is used in combination with the two-dimensional multiple-quantum magic angle spinning (MQMAS) NMR experiment in order to extract high-resolution CPMAS NMR spectra. The technique is demonstrated on (23)Na (S = 3/2), (17)O, (27)Al (both S = 5/2), and (45)Sc (S = 7/2) nuclei, showing the applicability of multiple-quantum cross-polarization to systems with differing spin quantum number, gyromagnetic ratio, and relative nuclide abundance. The utility of this two-dimensional MAS NMR experiment for spectral editing and site-specific measurement of cross-polarization intensities is demonstrated. The possibility of direct cross-polarization to higher order multiple-quantum coherences is also considered and three-, five-, and seven-quantum cross-polarized (45)Sc MAS NMR spectra are presented.
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Affiliation(s)
- S E Ashbrook
- School of Chemistry, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
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ASHBROOK SHARONE, WIMPERIS STEPHEN. Single- and multiple-quantum cross-polarization in NMR of quadrupolar nuclei in static samples. Mol Phys 2000. [DOI: 10.1080/00268970009483265] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ding S, Ye C. Corrections to the cross-polarization dynamics in solids. The effect of nonsecular terms of heteronuclear dipolar interaction on cross-relaxation. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1993; 1:321-328. [PMID: 7834307 DOI: 10.1016/0926-2040(93)90014-e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The dynamic theory of cross-polarization in solids is modified by considering the contribution of the nonsecular terms of the heteronuclear dipolar interaction Hamiltonian in the laboratory frame to cross-relaxation. This contribution is evaluated numerically and confirmed experimentally. It is shown that these nonsecular terms may play a considerable role in cross-relaxation in many systems, especially in those with fast internal molecular motion. The complication in the cross-polarization process is further revealed.
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Affiliation(s)
- S Ding
- Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics, Chinese Academy of Sciences
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Grey C, Veeman W. The detection of weak heteronuclear coupling between spin 1 and spin nuclei in MAS NMR; 14N/13C/1H triple resonance experiments. Chem Phys Lett 1992. [DOI: 10.1016/0009-2614(92)85486-t] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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16
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Garroway A, Miller J. Demonstration of indirect detection of 14N |δm| = 2 (overtone) NMR transitions. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0022-2364(89)90221-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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A simple pulse train, using 90° hard pulses, for selective excitation in high-resolution solid-state NMR. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/0022-2364(88)90246-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Kowalewski J, Einarsson L, Nordenskiöld L, Rupprecht A. Multiple quantum 7Li NMR of oriented LiDNA. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/0022-2364(88)90117-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Limits of 14N1H double-quantum polarization-transfer spectroscopy with powdery solids. ACTA ACUST UNITED AC 1986. [DOI: 10.1016/0022-2364(86)90032-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Caravatti P, Bodenhausen G, Ernst R. Selective pulse experiments in high-resolution solid state NMR. ACTA ACUST UNITED AC 1983. [DOI: 10.1016/0022-2364(83)90279-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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Weitekamp DP, Garbow JR, Pines A. Determination of dipole coupling constants using heteronuclear multiple quantum NMR. J Chem Phys 1982. [DOI: 10.1063/1.444180] [Citation(s) in RCA: 116] [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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