101
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Leskes M, Madhu PK, Vega S. Supercycled homonuclear dipolar decoupling in solid-state NMR: Toward cleaner H1 spectrum and higher spinning rates. J Chem Phys 2008; 128:052309. [DOI: 10.1063/1.2834730] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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102
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Blanc F, Copéret C, Lesage A, Emsley L. High resolution solid state NMRspectroscopy in surface organometallic chemistry: access to molecular understanding of active sites of well-defined heterogeneous catalysts. Chem Soc Rev 2008; 37:518-26. [DOI: 10.1039/b612793m] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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103
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Brus J, Urbanová M, Strachota A. Epoxy Networks Reinforced with Polyhedral Oligomeric Silsesquioxanes: Structure and Segmental Dynamics as Studied by Solid-State NMR. Macromolecules 2007. [DOI: 10.1021/ma702140g] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jiri Brus
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky sq. 2, 162 06 Prague 6, Czech Republic
| | - Martina Urbanová
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky sq. 2, 162 06 Prague 6, Czech Republic
| | - Adam Strachota
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky sq. 2, 162 06 Prague 6, Czech Republic
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104
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Wang X, Gu Q, Sun Q, Zhou D, Sun P, Xue G. Characterization of Polymer Compatibility by 1H Dipolar Filter Solid-State NMR under Fast Magic Angle Spinning. Macromolecules 2007. [DOI: 10.1021/ma071823c] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiaoliang Wang
- Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, People's Republic of China, and Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, People's Republic of China
| | - Qiang Gu
- Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, People's Republic of China, and Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, People's Republic of China
| | - Qing Sun
- Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, People's Republic of China, and Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, People's Republic of China
| | - Dongshan Zhou
- Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, People's Republic of China, and Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, People's Republic of China
| | - Pingchuan Sun
- Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, People's Republic of China, and Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, People's Republic of China
| | - Gi Xue
- Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, People's Republic of China, and Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, People's Republic of China
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105
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Chen Q, Schmidt-Rohr K. Backbone Dynamics of the Nafion Ionomer Studied by19F-13C Solid-State NMR. MACROMOL CHEM PHYS 2007. [DOI: 10.1002/macp.200700200] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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106
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Griffin J, Martin D, Brown S. Distinguishing Anhydrous and Hydrous Forms of an Active Pharmaceutical Ingredient in a Tablet Formulation Using Solid-State NMR Spectroscopy. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200702582] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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107
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Griffin JM, Martin DR, Brown SP. Distinguishing Anhydrous and Hydrous Forms of an Active Pharmaceutical Ingredient in a Tablet Formulation Using Solid-State NMR Spectroscopy. Angew Chem Int Ed Engl 2007; 46:8036-8. [PMID: 17847137 DOI: 10.1002/anie.200702582] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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108
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Leskes M, Madhu P, Vega S. A broad-banded z-rotation windowed phase-modulated Lee–Goldburg pulse sequence for 1H spectroscopy in solid-state NMR. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.09.041] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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109
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Li B, Xu L, Wu Q, Chen T, Sun P, Jin Q, Ding D, Wang X, Xue G, Shi AC. Various Types of Hydrogen Bonds, Their Temperature Dependence and Water−Polymer Interaction in Hydrated Poly(Acrylic Acid) as Revealed by 1H Solid-State NMR Spectroscopy. Macromolecules 2007. [DOI: 10.1021/ma070485c] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Baohui Li
- Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry and College of Physics, Nankai University, Tianjin, 300071, P. R. China, Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Co-ordination Chemistry, Nanjing University, Nanjing 210093, P. R. China, and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Lu Xu
- Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry and College of Physics, Nankai University, Tianjin, 300071, P. R. China, Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Co-ordination Chemistry, Nanjing University, Nanjing 210093, P. R. China, and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Qiang Wu
- Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry and College of Physics, Nankai University, Tianjin, 300071, P. R. China, Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Co-ordination Chemistry, Nanjing University, Nanjing 210093, P. R. China, and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Tiehong Chen
- Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry and College of Physics, Nankai University, Tianjin, 300071, P. R. China, Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Co-ordination Chemistry, Nanjing University, Nanjing 210093, P. R. China, and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Pingchuan Sun
- Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry and College of Physics, Nankai University, Tianjin, 300071, P. R. China, Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Co-ordination Chemistry, Nanjing University, Nanjing 210093, P. R. China, and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Qinghua Jin
- Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry and College of Physics, Nankai University, Tianjin, 300071, P. R. China, Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Co-ordination Chemistry, Nanjing University, Nanjing 210093, P. R. China, and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Datong Ding
- Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry and College of Physics, Nankai University, Tianjin, 300071, P. R. China, Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Co-ordination Chemistry, Nanjing University, Nanjing 210093, P. R. China, and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Xiaoliang Wang
- Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry and College of Physics, Nankai University, Tianjin, 300071, P. R. China, Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Co-ordination Chemistry, Nanjing University, Nanjing 210093, P. R. China, and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Gi Xue
- Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry and College of Physics, Nankai University, Tianjin, 300071, P. R. China, Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Co-ordination Chemistry, Nanjing University, Nanjing 210093, P. R. China, and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - An-Chang Shi
- Key Laboratory of Functional Polymer Materials, Ministry of Education, College of Chemistry and College of Physics, Nankai University, Tianjin, 300071, P. R. China, Department of Polymer Science and Engineering, The School of Chemistry and Chemical Engineering, State Key Laboratory of Co-ordination Chemistry, Nanjing University, Nanjing 210093, P. R. China, and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
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110
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Schaller T, Büchele UP, Klärner FG, Bläser D, Boese R, Brown SP, Spiess HW, Koziol F, Kussmann J, Ochsenfeld C. Structure of Molecular Tweezer Complexes in the Solid State: NMR Experiments, X-ray Investigations, and Quantum Chemical Calculations. J Am Chem Soc 2007; 129:1293-303. [PMID: 17263413 DOI: 10.1021/ja0666351] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structure of supramolecular complexes formed by a naphthalene-spaced tweezer molecule as host and 1,4-dicyanobenzene (DCNB), 1,2,4,5-tetracyanobenzene (TCNB), and 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) as aromatic, electron-deficient guests is investigated by solid-state NMR and X-ray diffraction measurements. Quantum chemical calculations using linear scaling methods are applied to predict and to assign the 1H NMR chemical shifts of the complexes. By combining experiment and theory, insights into intra- and intermolecular effects influencing the proton chemical shifts of the host-guest system are provided in the solid state.
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Affiliation(s)
- Torsten Schaller
- Universität Duisburg-Essen, Institut für Organische Chemie, D-45117 Essen, Germany.
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111
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Harris RK, Cadars S, Emsley L, Yates JR, Pickard CJ, Jetti RKR, Griesser UJ. NMR crystallography of oxybuprocaine hydrochloride, Modification II degrees. Phys Chem Chem Phys 2006; 9:360-8. [PMID: 17199152 DOI: 10.1039/b614318k] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The (13)C CPMAS spectrum is presented for the polymorph of oxybuprocaine hydrochloride which is stable at room temperature, i.e. Mod. II degrees . It shows crystallographic splittings arising from the fact that there are two molecules, with substantially different conformations, in the asymmetric unit. An INADEQUATE two-dimensional experiment was used to link signals for the same independent molecule. The chemical shifts are discussed in relation to the crystal structure. Of the four ethyl groups attached to NH(+) nitrogens, one gives rise to unusually low chemical shifts, very different from those of the other three ethyl groups. This is attributed empirically to gamma-gauche conformational effects, as is confirmed by shielding computations. These considerations allow (13)C signals to be assigned to specific carbons in the two crystallographically inequivalent molecules in the crystal structure. Indeed, information about the conformations is inherent in the NMR spectrum, which thus provides data of crystallographic significance. A (13)C/(1)H HETCOR experiment enabled resolution to be obtained in the (1)H dimension and allowed (1)H and (13)C signals for the same independent molecule to be linked.
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Affiliation(s)
- Robin K Harris
- Department of Chemistry, University of Durham, South Road, Durham, UK DH1 3LE.
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112
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Blanc F, Copéret C, Thivolle-Cazat J, Basset JM, Lesage A, Emsley L, Sinha A, Schrock RR. Better Characterization of Surface Organometallic Catalysts through Resolution Enhancement in Proton Solid State NMR Spectra. Inorg Chem 2006; 45:9587-92. [PMID: 17083261 DOI: 10.1021/ic061222m] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Delayed-acquisition methods, namely, echo and constant-time-acquisition approaches, allow a significant improvement in resolution in the proton solid state NMR spectra of surface organometallic catalysts such as [syn-(SiO)Mo(=NAr)(=CH(t)Bu)(CH2(t)Bu)] and [(SiO)Re(C(t)Bu)(=CH(t)Bu)(CH2(t)Bu)] (syn/anti ratio = 1:1). This enables the observation of all of the proton resonances, which is not possible with the simple proton single-pulse technique under magic-angle spinning. For example, the methylene protons of the neopentyl ligands, buried in the large peak associated with all of the methyls in the 1H MAS spectrum, can easily be identified by recording a delayed-acquisition spectrum (resolution enhancement of a factor of 3 is obtained). Moreover, combining constant-time acquisition with heteronuclear carbon-proton correlation spectroscopy also improves the resolution of the 2D HETCOR spectra.
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Affiliation(s)
- Frédéric Blanc
- Laboratoire de Chimie Organométallique de Surface, UMR 9986 CNRS - ESCPE Lyon, 43 bd du 11 Novembre 1918, F-69616 Villeurbanne Cedex, France
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113
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Leskes M, Madhu PK, Vega S. Proton line narrowing in solid-state nuclear magnetic resonance: New insights from windowed phase-modulated Lee-Goldburg sequence. J Chem Phys 2006; 125:124506. [PMID: 17014190 DOI: 10.1063/1.2352737] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present here a bimodal Floquet analysis of the windowed phase-modulated Lee-Goldburg (wPMLG) sequence for homonuclear dipolar decoupling. One of the main criteria for an efficient homonuclear dipolar decoupling scheme is an effective z-rotation condition. This is brought about by the presence of radio-frequency imperfections in the pulse sequence together with a systematic manipulation of the wPMLG pulses. Additional improvement in the (1)H spectral resolution was obtained by a proper understanding of the off-resonance dependence of the wPMLG irradiation scheme based on bimodal Floquet theory. Numerical investigations further corroborate both theoretical and experimental findings. Theoretical analysis points to accidental degeneracies between the cycle time of the wPMLG sequence and the rotor period leading to the experimentally observed off-resonance dependence of the resolution. Two-dimensional (1)H-(1)H homonuclear single-quantum correlation spectra of model amino acids are also presented, highlighting the improved spectral resolution of wPMLG sequences.
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Affiliation(s)
- Michal Leskes
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
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114
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Elena B, Pintacuda G, Mifsud N, Emsley L. Molecular Structure Determination in Powders by NMR Crystallography from Proton Spin Diffusion. J Am Chem Soc 2006; 128:9555-60. [PMID: 16848494 DOI: 10.1021/ja062353p] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The inability to determine molecular structures from powdered samples is a key barrier to progress in many areas of molecular and materials science. We report an approach to structure determination that combines molecular modeling with experimental spin diffusion data obtained from the high-resolution solid-state nuclear magnetic resonance of protons, and which allows the determination of the three-dimensional structure of an organic compound, in powder form and at natural isotopic abundance.
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Affiliation(s)
- Bénédicte Elena
- Laboratoire de Chimie, UMR 5182 CNRS/ENS, Laboratoire de Recherche Conventionné du CEA (DSV 23V / DSM 0432), Ecole Normale Supérieure de Lyon, 69364 Lyon, France
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115
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Mifsud N, Elena B, Pickard CJ, Lesage A, Emsley L. Assigning powders to crystal structures by high-resolution (1)H-(1)H double quantum and (1)H-(13)C J-INEPT solid-state NMR spectroscopy and first principles computation. A case study of penicillin G. Phys Chem Chem Phys 2006; 8:3418-22. [PMID: 16855720 DOI: 10.1039/b605227d] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We show how powder samples at natural isotopic abundance can be assigned to crystal structures by using high-resolution proton and carbon-13 solid-state NMR spectra in combination with first principles calculations. Homonuclear proton double-quantum spectra in combination with through-bond proton-carbon HSQC spectra are used to assign the NMR spectra. We then show that the proton chemical shifts can be included in the process of assigning the spectra to a crystal structure using first principles calculations. The method is demonstrated on the K salt of penicillin G.
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Affiliation(s)
- Nicolas Mifsud
- Laboratoire de Chimie (UMR 5182 ENS/CNRS), Laboratoire de Recherche Conventionné du CEA (DSV 23V/DSM 0432), Ecole Normale Supérieure de Lyon, 46, Allée d'Italie, 69364 Lyon, France
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116
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Lesage A, Emsley L, Penin F, Böckmann A. Investigation of Dipolar-Mediated Water−Protein Interactions in Microcrystalline Crh by Solid-State NMR Spectroscopy. J Am Chem Soc 2006; 128:8246-55. [PMID: 16787089 DOI: 10.1021/ja060866q] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Water-protein interactions play a major role in protein folding, structure, and function, and solid-state NMR has recently been shown to be a powerful tool for the site-resolved observation of these interactions in solid proteins. In this article we report investigations on possible water-protein dipolar transfer mechanisms in the microcrystalline deuterated protein Crh by a set of solid-state NMR techniques. Double-quantum (DQ) filtered and edited heteronuclear correlation experiments are used to follow direct dipolar water-protein magnetization transfers. Experimental data reveal no evidence for "solid-like" water molecules, indicating that residence times of solvent molecules are shorter than required for DQ creation, typically a few hundred microseconds. An alternative magnetization pathway, intermolecular cross-relaxation via heteronuclear nuclear Overhauser effects (NOEs), is probed by saturation transfer experiments. The significant additional enhancements observed when irradiating at the water frequency can possibly be attributed to direct heteronuclear water-protein NOEs; however, a contribution from relayed magnetization transfer via chemical exchange or proton-proton dipolar mechanisms cannot be excluded.
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Affiliation(s)
- Anne Lesage
- Laboratoire de Chimie (UMR 5182 ENS/CNRS), Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon, France
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117
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Chevelkov V, Rehbein K, Diehl A, Reif B. Ultrahigh Resolution in Proton Solid-State NMR Spectroscopy at High Levels of Deuteration. Angew Chem Int Ed Engl 2006; 45:3878-81. [PMID: 16646097 DOI: 10.1002/anie.200600328] [Citation(s) in RCA: 281] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Veniamin Chevelkov
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
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118
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Chevelkov V, Rehbein K, Diehl A, Reif B. Ultrahochaufgelöste1H-MAS-Festkörper-NMR-Spektren unter Verwendung von hohen Deuterierungsgraden. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200600328] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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119
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Nishiyama Y, Yamazaki T, Terao T. Development of modulated rf sequences for decoupling and recoupling of nuclear-spin interactions in sample-spinning solid-state NMR: Application to chemical-shift anisotropy determination. J Chem Phys 2006; 124:64304. [PMID: 16483204 DOI: 10.1063/1.2141949] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
An approach to design modulated rf sequences under sample spinning which decouple/recouple a specific nuclear-spin interaction in solid-state NMR is presented. The Euler angles of the spin rotation caused by a general rf field are forced to fulfill the symmetry principle theory for selecting an interaction of interest. Then, modulated rf sequences are directly obtained from the Euler angles with a large degree of freedom. rf sequences with high performance can be selected from them by numerically optimizing rf sequence parameters. As an example of this approach, an amplitude- and phase-modulated rf sequence to recouple chemical-shift anisotropy (CSA) is developed, which is robust with respect to rf inhomogeneity. Two-dimensional (2D) experiments with this rf sequence under on and off magic-angle spinning (MAS) provide one-dimensional and 2D powder patterns, respectively. The latter enables us to determine the CSA principal values more accurately even for overlapped signals in MAS spectra. The effectiveness of this modulated rf sequence is experimentally demonstrated on [(15)N]-N-acetyl-D,L-alanine for determination of the (15)N and (13)CO CSA principal values.
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Affiliation(s)
- Yusuke Nishiyama
- RIKEN Genomic Sciences Center, Suehiro-cho, Tsurumi, Yokohama, Kanagawa, Japan.
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120
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Blanc F, Copéret C, Thivolle-Cazat J, Basset JM, Lesage A, Emsley L, Sinha A, Schrock RR. Surface versus Molecular Siloxy Ligands in Well-Defined Olefin Metathesis Catalysts: [{(RO)3SiO}Mo(NAr)(CHtBu)(CH2tBu)]. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200503205] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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121
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Blanc F, Copéret C, Thivolle-Cazat J, Basset JM, Lesage A, Emsley L, Sinha A, Schrock RR. Surface versus Molecular Siloxy Ligands in Well-Defined Olefin Metathesis Catalysts: [{(RO)3SiO}Mo(NAr)(CHtBu)(CH2tBu)]. Angew Chem Int Ed Engl 2006; 45:1216-20. [PMID: 16416453 DOI: 10.1002/anie.200503205] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Frédéric Blanc
- Laboratoire de Chimie Organométallique de Surface, UMR 9986 CNRS--ESCPE Lyon, 43 bd du 11 Novembre 1918, 69616 Villeurbanne Cedex, France
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122
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Abstract
This review article describes the applications of NMR to the study of polymorphs and related forms (solvates) of organic (especially pharmaceutical) compounds, for which it is of increasing academic and practical importance. The nature of the systems covered is briefly introduced, as are the techniques constituting solid-state NMR. The methodologies involved are then reviewed under a number of different headings, ranging from spectral editing through relaxation times to shielding tensors and NMR crystallography. In each case the relevant applications are described. Whilst most studies concentrate on structural matters, motional effects are not neglected. A special section discusses studies of solvates (especially hydrates), and another reviews quantitative analysis.
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Affiliation(s)
- Robin K Harris
- Department of Chemistry, University of Durham, South Road, Durham, UK DH1 3LE.
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123
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Elena B, Lesage A, Steuernagel S, Böckmann A, Emsley L. Proton to Carbon-13 INEPT in Solid-State NMR Spectroscopy. J Am Chem Soc 2005; 127:17296-302. [PMID: 16332079 DOI: 10.1021/ja054411x] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A refocused INEPT through-bond coherence transfer technique is demonstrated for NMR of rigid organic solids and is shown to provide a valuable building block for the development of NMR correlation experiments in biological solids. The use of efficient proton homonuclear dipolar decoupling in combination with a direct spectral optimization procedure provides minimization of the transverse dephasing of coherences and leads to very efficient through-bond (1)H-(13)C INEPT transfer for crystalline organic compounds. Application of this technique to 2D heteronuclear correlation spectroscopy leads to up to a factor of 3 increase in sensitivity for a carbon-13 enriched sample in comparison to standard through-bond experiments and provides excellent selectivity for one-bond transfer. The method is demonstrated on a microcrystalline sample of the protein Crh (2 x 10.4 kDa).
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Affiliation(s)
- Bénédicte Elena
- Laboratoire de Chimie (UMR 5182 CNRS/ENS), Ecole Normale Supérieure de Lyon, 69364 Lyon, France
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124
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Böckmann A, Juy M, Bettler E, Emsley L, Galinier A, Penin F, Lesage A. Water-protein hydrogen exchange in the micro-crystalline protein crh as observed by solid state NMR spectroscopy. JOURNAL OF BIOMOLECULAR NMR 2005; 32:195-207. [PMID: 16132820 DOI: 10.1007/s10858-005-8073-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2005] [Accepted: 05/19/2005] [Indexed: 05/04/2023]
Abstract
We report site-resolved observation of hydrogen exchange in the micro-crystalline protein Crh. Our approach is based on the use of proton T2' -selective 1H-13C-13C correlation spectra for site-specific assignments of carbons nearby labile protein protons. We compare the proton T2' selective scheme to frequency selective water observation in deuterated proteins, and discuss the impacts of deuteration on 13C linewidths in Crh. We observe that in micro-crystalline proteins, solvent accessible hydroxyl and amino protons show comparable exchange rates with water protons as for proteins in solution, and that structural constraints, such as hydrogen bonding or solvent accessibility, more significantly reduce exchange rates.
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Affiliation(s)
- Anja Böckmann
- BioSciences Lyon-Gerland, Institut de Biologie et Chimie des Protéines UMR 5086 CNRS/ULCB, 7, passage du Vercors, 69367, Lyon, France.
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125
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Abstract
The investigation of 1H-1H spin-diffusion build-up curves using a rate matrix analysis approach shows that high-resolution magic angle spinning NMR of protons, applied to powdered organic compounds, provides a method to probe crystalline arrangements. The comparison between experimental 1H data and simulation is shown to depend strongly on the parameters of the crystal structure, for example on the unit cell parameters or the orientation of the molecule in the unit cell, and those parameters are experimentally determined for a model organic compound.
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Affiliation(s)
- Bénédicte Elena
- Laboratoire de Chimie (UMR 5182 CNRS/ENS), Ecole Normale Supérieure de Lyon, 69364 Lyon, France
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126
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Brown SP, Lesage A, Elena B, Emsley L. Probing proton-proton proximities in the solid state: high-resolution two-dimensional 1H-1H double-quantum CRAMPS NMR spectroscopy. J Am Chem Soc 2005; 126:13230-1. [PMID: 15479070 DOI: 10.1021/ja045461p] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new 1H DQ (double-quantum) CRAMPS (combined rotation and multiple-pulse sequence) solid-state nuclear magnetic resonance experiment incorporating DUMBO homonuclear 1H dipolar decoupling is presented. The major resolution enhancement enables DQ peaks corresponding to all 22 close (<3.5 A) proton-proton proximities in the dipeptide beta-AspAla to be observed. In particular, the DQ CRAMPS spectrum provides access to the alkyl region of the spectrum and yields a clear assignment of the two CH and two diastereotopic CH2 proton resonances.
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Affiliation(s)
- Steven P Brown
- Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom.
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127
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Elena B, de Paëpe G, Emsley L. Direct spectral optimisation of proton–proton homonuclear dipolar decoupling in solid-state NMR. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.09.122] [Citation(s) in RCA: 174] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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128
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Vega AJ. Controlling the effects of pulse transients and RF inhomogeneity in phase-modulated multiple-pulse sequences for homonuclear decoupling in solid-state proton NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2004; 170:22-41. [PMID: 15324755 DOI: 10.1016/j.jmr.2004.05.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Revised: 05/20/2004] [Indexed: 05/24/2023]
Abstract
The effects of pulse imperfections and RF inhomogeneity on NMR spectra obtained with phase-modulated multiple-pulse NMR sequences are analyzed. The emphasis is on the combined effects of frequency offset, RF inhomogeneity, and pulse phase transients. To enable a theoretical description of the transients associated with phase changes under continuous RF irradiation, the nature of the transients is investigated in depth. As monitored in our 300 MHz spectrometer, they are found to be caused by linear elements of the RF circuitry. The validity of their representation as delta-function pulses and the significance of their decomposition into antisymmetric and symmetric components are discussed. A practical method for quantitative control of the antisymmetric phase transients is proposed. The linearity property allows the development of a theoretical description of the spin dynamics caused by the transients. This leads to a vector-Hamiltonian model for phase-modulated Lee-Goldburg experiments. It quantitatively predicts both the frequency shift and the line broadening caused by antisymmetric phase transients and their coupling with RF inhomogeneity. The model is shown to be equally applicable to frequency-switched Lee-Goldburg experiments. A noteworthy discovery is that for a given magnitude of the antisymmetric phase transients a frequency offset exists at which the inhomogeneity broadening is essentially canceled. This explains the common observation that for best resolution one side of resonance is preferred over the other. It also suggests a strategy for enhancing resolution without having to resort to severe sample volume restriction. Numerical calculations verified the theoretical predictions and allowed extension of the model to BLEW-12 and DUMBO-1. Experimental verification is presented. The deviations from theoretical predictions are discussed.
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Affiliation(s)
- Alexander J Vega
- DuPont Central Research and Development, Experimental Station, P.O. Box 80356, Wilmington, DE 19880-0356, USA.
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129
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Madhu P, Vinogradov E, Vega S. Multiple-pulse and magic-angle spinning aided double-quantum proton solid-state NMR spectroscopy. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.07.034] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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130
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Bosman L, Madhu PK, Vega S, Vinogradov E. Improvement of homonuclear dipolar decoupling sequences in solid-state nuclear magnetic resonance utilising radiofrequency imperfections. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2004; 169:39-48. [PMID: 15183355 DOI: 10.1016/j.jmr.2004.04.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2003] [Revised: 03/31/2004] [Indexed: 05/24/2023]
Abstract
The often annoying imperfections in the phases and pulses of typical radiofrequency multiple-pulse irradiation schemes for homonuclear dipolar decoupling are revisited and analysed here. The analysis is with respect to one such multiple-pulse sequence, namely, the windowed phase-modulated Lee-Goldburg sequence. The error terms in the Hamiltonian due to pulse imperfections may lead to effective rotation of the spins around the z-axis giving rise to image free and high-resolution 1H spectra. Certain precautions to be taken with regard to scale factor estimation are also detailed. The analysis also points out the range of off-set values where the best homonuclear dipolar decoupling performance of a particular pulse scheme may be obtained.
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Affiliation(s)
- Leon Bosman
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
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131
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Lesage A, Böckmann A. Water−Protein Interactions in Microcrystalline Crh Measured by 1H−13C Solid-State NMR Spectroscopy. J Am Chem Soc 2003; 125:13336-7. [PMID: 14583011 DOI: 10.1021/ja036720y] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using solid-state NMR carbon-proton dipolar correlation spectroscopy, we observed hydrogen exchange on the millisecond time scale between water molecules and protein protons in a solid sample. These interactions are shown to be related to important structural features of the protein such as hydrogen-bonding or salt-bridge networks.
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Affiliation(s)
- Anne Lesage
- Laboratoire de Chimie, UMR 5532 CNRS-ENS, Ecole Normale Supérieure de Lyon, 46, allée d'Italie, 69364 Lyon, France.
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