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Jardón-Álvarez D, Kahn N, Houben L, Leskes M. Oxygen Vacancy Distribution in Yttrium-Doped Ceria from 89Y- 89Y Correlations via Dynamic Nuclear Polarization Solid-State NMR. J Phys Chem Lett 2021; 12:2964-2969. [PMID: 33730494 PMCID: PMC8006133 DOI: 10.1021/acs.jpclett.1c00221] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/12/2021] [Indexed: 05/25/2023]
Abstract
Comprehending the oxygen vacancy distribution in oxide ion conductors requires structural insights over various length scales: from the local coordination preferences to the possible formation of agglomerates comprising a large number of vacancies. In Y-doped ceria, 89Y NMR enables differentiation of yttrium sites by quantification of the oxygen vacancies in their first coordination sphere. Because of the extremely low sensitivity of 89Y, longer-range information was so far not available from NMR. Herein, we utilize metal ion-based dynamic nuclear polarization, where polarization from Gd(III) dopants provides large sensitivity enhancements homogeneously throughout the bulk of the sample. This enables following 89Y-89Y homonuclear dipolar correlations and probing the local distribution of yttrium sites, which show no evidence of the formation of oxygen vacancy rich regions. The presented approach can provide valuable structural insights for designing oxide ion conductors.
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Affiliation(s)
- Daniel Jardón-Álvarez
- Department
of Materials and Interfaces, Weizmann Institute
of Science, Rehovot 76100, Israel
| | - Nitzan Kahn
- Department
of Materials and Interfaces, Weizmann Institute
of Science, Rehovot 76100, Israel
| | - Lothar Houben
- Department
of Chemical Research Support, Weizmann Institute
of Science, Rehovot 76100, Israel
| | - Michal Leskes
- Department
of Materials and Interfaces, Weizmann Institute
of Science, Rehovot 76100, Israel
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2
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Procházková E, Cao C, Rawal A, Dračínský M, Bhattacharyya S, Císařová I, Hook JM, Stenzel MH. Polymorphic Transformation of Drugs Induced by Glycopolymeric Vesicles Designed for Anticancer Therapy Probed by Solid-State NMR Spectroscopy. ACS APPLIED MATERIALS & INTERFACES 2019; 11:28278-28288. [PMID: 31290309 DOI: 10.1021/acsami.9b05514] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Understanding the nature of the drug-polymer interactions in micellar drug delivery systems and what happens with the drug and the polymer once the complex has formed is essential for the rational design of the polymeric matrices suitable for a particular drug. In this work, glycopolymeric vesicles-a block copolymer, poly(1-O-methacryloyl-β-d-fructopyranose)-b-poly(methyl methacrylate), (PFru36-PMMA160),-designed to target tumor cells loaded with two drugs, ellipticine and curcumin, were characterized. Advanced solid-state NMR spectroscopy and single-crystal/powder X-ray diffraction (XRD) combined with CASTEP calculations shed light on the nature of the drug, the polymer, and their interactions. While the low drug loading (ca. 5%) ensured that the structure, size, and shape of the polymeric vesicles did not change significantly, the solid-state forms of the drugs changed markedly. Upon loading into the vesicles, ellipticine favored a highly ordered form distinctly different from the bulk drug as indicated by 13C solid-state NMR spectroscopy. A detailed analysis of the CASTEP-calculated 13C spectra derived from crystallographic data based on the lowest mean absolute error showed the best match with form I. Moreover, ellipticine before loading was found as a new polymorph and was described by single-crystal XRD as a new orthorhombic Form III. Likewise, curcumin, originally present in monoclinic Form I was found to recrystallize as metastable orthorhombic Form II inside the vesicles. Intermolecular interactions between the polymeric vesicles and the drugs, ellipticine as well as curcumin, were detected using 2D 1H magic angle spinning experiments, indicating that the drugs are localized in the hydrophobic layer of the vesicles.
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Affiliation(s)
- Eliška Procházková
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , Prague 166 10 , Czech Republic
| | | | | | - Martin Dračínský
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , Prague 166 10 , Czech Republic
| | | | - Ivana Císařová
- Faculty of Science , Charles University , Prague 128 43 , Czech Republic
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3
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Guo B, Yang H, Yao Q, Zeng S, Wang D, Li D, Dou J. Syntheses, structures and field-dependent slow magnetic relaxation of saddle-like Cu 4 and reverse “U” shape Mn 3 complexes. INORG CHEM COMMUN 2017. [DOI: 10.1016/j.inoche.2017.03.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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4
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Das BB, Lin EC, Opella SJ. Experiments optimized for magic angle spinning and oriented sample solid-state NMR of proteins. J Phys Chem B 2013; 117:12422-31. [PMID: 24044695 DOI: 10.1021/jp407154h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Structure determination by solid-state NMR of proteins is rapidly advancing as a result of recent developments of samples, experimental methods, and calculations. There are a number of different solid-state NMR approaches that utilize stationary samples, aligned samples, or magic angle spinning of unoriented "powder" samples, and depending on the sample and the experimental method they can emphasize the measurement of distances or angles, ideally both, as sources of structural constraints. Multidimensional correlation spectroscopy of low-gamma nuclei such as (15)N and (13)C is an important step for making resonance assignments and measurements of angular restraints in membrane proteins. However, the efficiency of coherence transfer predominantly depends upon the strength of the dipole-dipole interaction, and this can vary from site to site and between sample alignments, for example, during the mixing of (13)C and (15)N magnetization in stationary aligned and in magic angle spinning samples. Here, we demonstrate that the efficiency of polarization transfer can be improved by using adiabatic demagnetization and remagnetization techniques on stationary aligned samples, and proton assisted insensitive nuclei cross-polarization in magic angle sample spinning samples. The adiabatic cross-polarization technique provides an alternative mechanism for spin-diffusion experiments correlating (15)N/(15)N and (15)N/(13)C chemical shifts over large distances. Improved efficiency in cross-polarization with 40-100% sensitivity enhancements is observed in proteins and single crystals, respectively. We describe solid-state NMR experimental techniques that are optimal for membrane proteins in liquid crystalline phospholipid bilayers under physiological conditions. The techniques are illustrated with data from single crystals both of peptides and of membrane proteins in phospholipid bilayers.
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Affiliation(s)
- Bibhuti B Das
- University of California, San Diego , 9500 Gilman Drive, 0307 La Jolla, California 92093-0307, United States
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5
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Colquhoun IJ, Packer KJ. Nuclear magnetic resonance in solid ethylene/α-olefin copolymers: Relaxation, spin-diffusion and lamellar widths. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/pi.4980190208] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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6
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Vogt FG, Strohmeier M. 2D solid-state NMR analysis of inclusion in drug-cyclodextrin complexes. Mol Pharm 2012; 9:3357-74. [PMID: 23009557 DOI: 10.1021/mp300416w] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The solubility of drug molecules can often be improved through preparation and delivery of cyclodextrin (CD) inclusion complexes. These drug-oligosaccharide complexes can be prepared in solution and converted to the solid state via methods such as lyophilization and spray-drying, or they can be prepared directly from solids by a variety of methods. The development of drug-CD complexes as solids allows for potential advantages in dosage form design, such as the preparation of layered formulations, and it also can yield improvements in chemical and physical stability. 2D solid-state NMR (SSNMR) methods provide a direct way to probe drug-CD interactions in solid complexes through dipolar interactions between nuclei within the drug and CD molecules. In this study, 2D heteronuclear and homonuclear correlation SSNMR experiments involving (1)H, (13)C, (19)F, and (31)P nuclei are used to demonstrate the inclusion of drug within the CD cavity in a variety of powder samples. To illustrate the general applicability of the SSNMR approach presented, examples are shown for the drugs diflunisal, adefovir dipivoxil, voriconazole, dexamethasone, and prednisolone in complexes with α-CD, β-CD, and sulfobutylether-substituted β-CD. The quantitative analysis of included and free drug fractions in a solid drug-CD complex using SSNMR is also demonstrated. On the basis of these results, general approaches to the characterization of these materials using SSNMR are proposed.
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Affiliation(s)
- Frederick G Vogt
- Product Development, GlaxoSmithKline plc, 709 Swedeland Road, King of Prussia, Pennsylvania 19406, United States.
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7
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Lin X, Ideta K, Miyawaki J, Nishiyama Y, Mochida I, Yoon SH. High magnetic field solid-state NMR analyses by combining MAS, MQ-MAS, homo-nuclear and hetero-nuclear correlation experiments. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012; 50:289-294. [PMID: 22392761 DOI: 10.1002/mrc.3804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Revised: 01/22/2012] [Accepted: 02/03/2012] [Indexed: 05/31/2023]
Abstract
A general strategy of structural analysis of alumina silicate by combining various solid-state NMR measurements such as single pulse, multi-quantum magic angle spinning, double-quantum homo-nuclear correlation under magic angle spinning (DQ-MAS), and cross-polarization hetero-nuclear correlation (CP-HETCOR) was evaluated with the aid of high magnetic field NMR (800 MHz for (1) H Larmor frequency) by using anorthite as a model material. The high magnetic field greatly enhanced resolution of (27) Al in single pulse, DQ-MAS, and even in triple-quantum magic angle spinning NMR spectra. The spatial proximities through dipolar couplings were probed by the DQ-MAS methods for homo-nuclear correlations between both (27) Al-(27) Al and (29) Si-(29) Si and by CP-HETCOR for hetero-nuclear correlations between (27) Al-(29) Si in the anorthite framework. By combining various NMR methodologies, we elucidated detailed spatial correlations among various aluminum and silicon species in anorthite that was hard to be determined using conventional analytical methods at low magnetic field. Moreover, the presented approach is applicable to analyze other alumina-silicate minerals.
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Affiliation(s)
- Xiongchao Lin
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka, 816-8580, Japan
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8
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Vogt FG, Williams GR. Analysis of a Nanocrystalline Polymer Dispersion of Ebselen Using Solid-State NMR, Raman Microscopy, and Powder X-ray Diffraction. Pharm Res 2012; 29:1866-81. [DOI: 10.1007/s11095-012-0713-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Accepted: 02/15/2012] [Indexed: 11/29/2022]
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9
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Zou Q, Zhang L, Li S, Gao X, Deng F. A solid-state NMR study of structure and segmental dynamics of poly(propylmethacryl-heptaisobutyl-pss)-co-styrene nanocomposites. J Colloid Interface Sci 2011; 355:334-41. [PMID: 21216408 DOI: 10.1016/j.jcis.2010.12.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 12/11/2010] [Accepted: 12/14/2010] [Indexed: 11/18/2022]
Abstract
The domain structure and mobility of poly(propylmethacryl-heptaisobutyl-pss)-co-styrene nanocomposites with different polyhedral oligomeric silsesquioxane (POSS) contents were investigated by various solid-state NMR techniques in combination with XRD. The NMR relaxation time measurements suggested that increasing POSS content trended to mobilize the chains in PS unit. Although XRD results showed that POSS was well dispersed into the polymer matrix, 2D WISE NMR indicated that the dispersion of POSS into the polymer matrix led to a composite structure composed of rigid and densely packed PS domain and mobile and amorphous POSS domain. This implied that the size of the two domains was very small. 2D HETCOR NMR implied that the distance between PS network and POSS unit gradually decreased when the POSS content successively increased. The dispersed POSS domain size determined by 2D spin-diffusion NMR experiments was increased with the POSS loading, being about 3.0, 3.9, 6.0 nm for the POSS15, POSS25 and POSS45 nanocomposites, respectively.
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Affiliation(s)
- Qin Zou
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, the Chinese Academy of Sciences, Wuhan 430071, PR China
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10
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Aguilar-Parrilla F, Limbach HH, Klein O, Elguero J. A dynamic 15N NMR study of kinetic hydrogen/deuterium isotope and tunnel effects on the triple proton transfer in crystalline 3,5-dimethylpyrazole. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19971010604] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Pfeffer PE. High Resolution Solid State13C NMR and its Applications in Carbohydrate Chemistry. J Carbohydr Chem 2006. [DOI: 10.1080/07328308408057921] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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12
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Robyr P, Tomaselli M, Straka J, Grob-Pisano C, Suter U, Meier B, Ernst R. RF-driven and proton-driven NMR polarization transfer for investigating local order. Mol Phys 2006. [DOI: 10.1080/00268979500100691] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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13
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Klein O, Aguilar-Parrilla F, Lopez JM, Jagerovic N, Elguero J, Limbach HH. Dynamic NMR Study of the Mechanisms of Double, Triple, and Quadruple Proton and Deuteron Transfer in Cyclic Hydrogen Bonded Solids of Pyrazole Derivatives. J Am Chem Soc 2004; 126:11718-32. [PMID: 15366920 DOI: 10.1021/ja0493650] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Using dynamic solid state (15)N CPMAS NMR spectroscopy (CP = cross polarization, MAS = magic angle spinning), the kinetics of the degenerate intermolecular double and quadruple proton and deuteron transfers in the cyclic dimer of (15)N labeled polycrystalline 3,5-diphenyl-4-bromopyrazole (DPBrP) and in the cyclic tetramer of (15)N labeled polycrystalline 3,5-diphenylpyrazole (DPP) have been studied in a wide temperature range at different deuterium fractions in the mobile proton sites. Rate constants were measured on a millisecond time scale by line shape analysis of the doubly (15)N labeled compounds, and by magnetization transfer experiments on a second timescale of the singly (15)N labeled compounds in order to minimize the effects of proton-driven (15)N spin diffusion. For DPBrP the multiple kinetic HH/HD/DD isotope effects could be directly obtained. By contrast, four rate constants k(1) to k(4) were obtained for DPP at different deuterium fractions. Whereas k(1) corresponds to the rate constant k(HHHH) of the HHHH isotopolog, an appropriate kinetic reaction model was needed for the kinetic assignment of the other rate constants. Using the model described by Limbach, H. H.; Klein, O.; Lopez Del Amo, J. M.; Elguero, J. Z. Phys. Chem. 2004,218, 17, a concerted quadruple proton-transfer mechanism as well as a stepwise consecutive single transfer mechanism could be excluded. By contrast, using the kinetic assignment k(2) approximately k(3) approximately k(HHHD) approximately k(HDHD) and k(3) approximately k(HDDD) approximately k(DDDD), the results could be explained in terms of a two-step process involving a zwitterionic intermediate. In this mechanism, each reaction step involves the concerted transfer of two hydrons, giving rise to primary kinetic HH/HD/DD isotope effects, whereas the nontransferred hydrons only contribute small secondary effects, which are not resolved experimentally. By contrast, the multiple kinetic isotope effects of the double proton transfer in DPBrP and of the triple proton proton transfer in cyclic pyrazole trimers studied previously indicate concerted transfer processes. Thus, between n = 3 and 4 a switch of the reaction mechanism takes place. This switch is rationalized in terms of hydrogen bond compression effects associated with the multiple proton transfers. The Arrhenius curves of all processes are nonlinear and indicate tunneling processes at low temperatures. In a preliminary analysis, they are modeled in terms of the Bell-Limbach tunneling model.
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Affiliation(s)
- Oliver Klein
- Contribution from the Institut für Chemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany
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14
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Pfleiderer B, Albert K, Bayer E, Lork KD, Unger KK, Brückner H. Correlation of the Dynamic Behavior ofn-Alkyl Ligands of the Stationary Phase with the Retention Times of Paracelsin Peptides in Reversed Phase HPLC. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/anie.198903271] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Blümich B, Spiess HW. Two-Dimensional Solid-State NMR Spectroscopy: New Possibilities for the Investigation of the Structure and Dynamics of Solid Polymers [New Analytical Methods (38)]. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/anie.198816551] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Sozzani P, Bracco S, Comotti A, Simonutti R, Camurati I. Stoichiometric Compounds of Magnesium Dichloride with Ethanol for the Supported Ziegler−Natta Catalysis: First Recognition and Multidimensional MAS NMR Study. J Am Chem Soc 2003; 125:12881-93. [PMID: 14558837 DOI: 10.1021/ja034630n] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Ethanol associates easily with MgCl(2) to form adducts of complex architecture, but until now available characterization methods have failed to identify the pure stoichiometric compounds and their structures. To remedy this, we set about applying homonuclear and heteronuclear 2D correlated solid-state NMR spectroscopy to identify the pure compounds and the ethanol-to-magnesium coordination pattern. High spinning speed and Lee-Goldburg sequences were able to reduce the hydrogen spin-diffusion and homonuclear coupling in the crystalline solid, thus achieving high resolution also in the hydrogen domain. On this basis, the pure adducts, of interest as catalyst supports for Ziegler-Natta polymerization, were isolated for the first time. Magnesium coordination sites with given numbers of ligands and their multiplicity in the crystal cells were determined in the new-found stoichiometric complexes. Variable temperature and 2D carbon-carbon exchange NMR, as well as relaxation times in the fast motion regime, revealed the disordering phenomena generated by ethanol dynamics in the crystal. Decoding the intriguing polymorphism of the precursors permits to trace the genealogy of tailored MgCl(2) titanate granules, active as highly productive catalysts for the stereospecific polymerization of olefins.
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Affiliation(s)
- Piero Sozzani
- Department of Materials Science, University of Milano-Bicocca, Via R. Cozzi 53, 20125 Milan, Italy.
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17
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Brachais L, Lauprêtre F, Caille JR, Teyssié D, Boileau S. Solid-state organization of poly(methylmethacrylate)–poly(methylphenylsiloxane) based interpenetrating networks. POLYMER 2002. [DOI: 10.1016/s0032-3861(01)00764-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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18
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Wang J, Cheung M, Mi Y. Miscibility of poly(ethyl oxazoline)/poly(4-vinylphenol) blends as investigated by the high-resolution solid-state 13C NMR. POLYMER 2001. [DOI: 10.1016/s0032-3861(00)00502-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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19
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Tekely P, Reichert D, Zimmermann H, Luz Z. Initial conditions for carbon-13 MAS NMR 1D exchange involving chemically equivalent and inequivalent nuclei. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2000; 145:173-183. [PMID: 10910685 DOI: 10.1006/jmre.2000.2092] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A major problem in dynamic 1D (13)C MAS NMR concerns the exchange between magnetically inequivalent, but chemically equivalent sites, whose signals are not resolved in the regular 1D spectrum. This difficulty may be overcome by properly preparing the initial nonequilibrium state of the spin system in the exchange experiments. In the present paper we discuss the advantages and limitations of several such experiments already in use and propose a new sequence, which we term SELDOM-ODESSA. Unlike the other 1D-exchange methods, this experiment yields pure absorption spectra that can more readily be analyzed quantitatively. The experiment is a hybrid comprising a SELDOM sequence, for selective excitation of one of the spinning sideband manifolds in the spectrum, followed by the ODESSA sequence, which induces alternate polarization in the excited sideband manifold. The evolution of the spectrum following this sequence provides information on both the exchange between congruent sites belonging to the same group of equivalent nuclei, and the exchange between inequivalent sites. Results are presented for a tropolone sample specifically enriched in carbon-13 at the carbonyl and hydroxyl sites. The dominant exchange mechanism in this sample involves spin diffusion. The various spin exchange processes in this sample, in the presence and absence of proton decoupling during the mixing time, are measured and discussed. Copyright 2000 Academic Press.
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Affiliation(s)
- P Tekely
- Laboratoire de Methodologie RMN, UPRESA CNRS 7042, Universite Henri Poincare, Nancy 1, Vandoeuvre-les-Nancy, 54506, France
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20
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van Beek JD, Kümmerlen J, Vollrath F, Meier BH. Supercontracted spider dragline silk: a solid-state NMR study of the local structure. Int J Biol Macromol 1999; 24:173-8. [PMID: 10342762 DOI: 10.1016/s0141-8130(98)00083-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The local structure of supercontracted dragline silk from the spider Nephila madagascariensis was investigated by solid-state nuclear magnetic resonance. Two-dimensional (2D) spin-diffusion experiments did not show any significant conformational changes in short-range order (and the secondary structure of the protein) upon supercontraction. Our results are in accordance with the proposal by Vollrath et al. (Proc R Soc London B 1996;263:147-151) that urea-supercontraction does not alter the local structure of spider dragline silk fundamentally. However, significant differences in the dynamics of the polypeptide chain upon supercontraction are detected at room temperature. At low temperature, these dynamics are frozen out. In addition, the role of the solvent (water) in the silk is investigated in Nephila edulis. Mobile water is detected at temperatures significantly below the freezing point of bulk water.
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Affiliation(s)
- J D van Beek
- NSR-Center for Molecular Structure, Design and Synthesis, Laboratory of Physical Chemistry, University of Nijmegen, The Netherlands
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21
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Zhu SH, Cheung MK, Chan CM. Interfacial characterization of compatibilized PVC/SBR blends by solid-state NMR and TEM. POLYMER 1998. [DOI: 10.1016/s0032-3861(98)00039-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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22
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Heinen W, Wenzel CB, Rosenmöller CH, Mulder FM, Boender GJ, Lugtenburg J, de Groot HJM, van Duin M, Klumperman B. Solid-State NMR Study of Miscibility and Phase Separation in Blends and Semi-Interpenetrating Networks of 13C-Labeled Poly(styrene-co-acrylonitrile) and Poly(styrene-co-maleic anhydride). Macromolecules 1998. [DOI: 10.1021/ma980436n] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wouter Heinen
- Leiden Institute of Chemistry, Gorlaeus Laboratories, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Cornelia B. Wenzel
- Leiden Institute of Chemistry, Gorlaeus Laboratories, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Carola H. Rosenmöller
- Leiden Institute of Chemistry, Gorlaeus Laboratories, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Fokko M. Mulder
- Leiden Institute of Chemistry, Gorlaeus Laboratories, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Gert Jan Boender
- Leiden Institute of Chemistry, Gorlaeus Laboratories, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Johan Lugtenburg
- Leiden Institute of Chemistry, Gorlaeus Laboratories, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Huub J. M. de Groot
- Leiden Institute of Chemistry, Gorlaeus Laboratories, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | | | - Bert Klumperman
- Eindhoven University of Technology, Laboratory of Polymer Chemistry, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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23
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Robyr P, Gan Z. Radiofrequency-Driven and Slow-Magic-Angle-Sample-Spinning Polarization-Transfer Techniques: A Comparative Study. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 1998; 131:254-260. [PMID: 9571101 DOI: 10.1006/jmre.1998.1359] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The rate constant of radiofrequency-driven (RF-driven) polarization transfer and that of polarization transfer under slow-magic-angle sample spinning (S-MAS) are compared using a model system, polycrystalline alpha-alpha'-13C2-phthalic acid. While the rate constant under RF irradiation in static samples strongly depends on the orientation of the internuclear vector, the rate constant under S-MAS is hardly sensitive to that orientation and, thus, depends almost exclusively on the internuclear distance. Consequently, polarization-transfer rate constants obtained under S-MAS can be interpreted more simply when used to study local order in polycrystalline or amorphous solids. Copyright 1998 Academic Press.
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Affiliation(s)
- P Robyr
- Laboratorium für Physikalische Chemie, ETH-Zentrum, Zürich, CH-8092, Switzerland
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24
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Ernst M, Meier BH. Spin Diffusion in Solids. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0167-6881(98)80007-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Kolodziejski W, Klinowski J. H → 31P, 31P → 1H, and 2H → 1H CP/MAS NMR Studies of the Large-Pore Gallophosphate Molecular Sieve Cloverite. J Phys Chem B 1997. [DOI: 10.1021/jp963418l] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Waclaw Kolodziejski
- Faculty of Pharmacy, Department of Inorganic and Analytical Chemistry, Warsaw Medical Academy, ul. Banacha 1, 02-097 Warszawa, Poland, and Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Jacek Klinowski
- Faculty of Pharmacy, Department of Inorganic and Analytical Chemistry, Warsaw Medical Academy, ul. Banacha 1, 02-097 Warszawa, Poland, and Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
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Kolodziejski W, Klinowski J. 31P → 1H cross-polarization and 1H spin diffusion NMR in the large-pore gallophosphate molecular sieve cloverite. Chem Phys Lett 1997. [DOI: 10.1016/s0009-2614(97)00029-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Kümmerlen J, van Beek JD, Vollrath F, Meier BH. Local Structure in Spider Dragline Silk Investigated by Two-Dimensional Spin-Diffusion Nuclear Magnetic Resonance†. Macromolecules 1996. [DOI: 10.1021/ma951098i] [Citation(s) in RCA: 224] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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29
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Wang W, Hu JZ, Alderman DW, Pugmire RJ, Grant DM. Use of relaxation agent doping to shorten very long spin-lattice relaxation times in a magic-angle turning experiment. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1995; 5:257-262. [PMID: 9053116 DOI: 10.1016/0926-2040(95)00041-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A practical method is described for measuring the principal values of the chemical shift tensors in compounds with very long proton spin-lattice relaxation times (T1). This technique involves shortening the effective proton T1. by mixing a compound of interest with another compound having a much shorter T1 value. The doped mixture, partly consisting of a monophasic glass, allows efficient intermolecular spin diffusion between the two compounds. Using a slow magic-angle turning (MAT) experiment, we have successfully used such mixtures to measure the principal values of the chemical shift tensors of all the carbons in dibenzofuran in just four days. Without using this technique the experimental time required for the pure compound would have been several months.
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Affiliation(s)
- W Wang
- Department of Chemistry, University of Utah, Salt Lake City 84112, USA
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Ba Y, Veeman WS. Multiple-quantum nuclear magnetic resonance spectroscopy of coupled 1/2 spins in solids. Combination with cross-polarization and magic-angle spinning. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1994; 3:249-269. [PMID: 7804784 DOI: 10.1016/0926-2040(94)90002-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Proton multiple-quantum coherence spectroscopy has been combined with magic-angle spinning (MAS) and cross-polarization (CP). This enables the detection of the proton (or any other abundant spin) multiple-quantum coherence spectrum via the high-resolution 13C (any other spin) nuclear magnetic resonance (NMR) spectrum. For this purpose multiple-quantum pulse sequences synchronised to sample rotation have been designed, and the average Hamiltonians of these sequences have been analysed. The analysis allows the design of optimal experimental conditions. As a demonstration of the technique, it has been applied to a mixture of adamantane and hexamethylethane. From earlier 13C spin diffusion experiments it was known that these two molecules form a mixed crystal. With our technique we detected two different phases with different molecular translational self-diffusion coefficients in this system.
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Affiliation(s)
- Y Ba
- Universität-GH-Duisburg, Germany
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Tomaselli M, Meier B, Baldus M, Eisenegger J, Ernst R. An rf-driven nuclear spin-diffusion experiment using zero-angle sample spinning. Chem Phys Lett 1994. [DOI: 10.1016/0009-2614(94)00596-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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35
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Eckert H. Structural Studies of Noncrystalline Solids Using Solid State NMR. New Experimental Approaches and Results. SOLID-STATE NMR IV METHODS AND APPLICATIONS OF SOLID-STATE NMR 1994. [DOI: 10.1007/978-3-642-79127-7_3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Deng F, Hu J, Xiong J, Du Y. Solid-state NMR studies of 1H spin diffusion in adsorbed organic molecules. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1993; 2:97-103. [PMID: 7812753 DOI: 10.1016/0926-2040(93)90027-k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
1H spin diffusion times of toluene (MB) and tetrahydrofuran (THF) adsorbed on a series of porous solids (charcoal, SiO2 and Al2O3) were measured by a selective inversion technique. The experimental results show that they cover a wide range (from less than one millisecond to several hundreds of milliseconds). For all samples, a tri-exponential behavior was observed in the magnetization recovery processes of the negative peaks. This is attributed to the existence of the two different kinds of spin diffusion processes in addition to the T1 relaxation. One is assigned to the intermolecular spin diffusion between the surface acidic protons of the adsorbent and the organic molecules adsorbed on the solid surface, the other to the intramolecular spin diffusion of adsorbed molecules. Due to hydrogen bonding between the surface hydroxyl groups and the adsorbate, the intermolecular spin diffusion of THF adsorbed on various solids is more effective compared to that of adsorbed MB. In addition, the intermolecular 1H spin diffusion between charcoal and adsorbed THF molecules was confirmed by indirect measurement suggested by Tekely et al.
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Affiliation(s)
- F Deng
- State Key Laboratory of Magnetic Resonance, Chinese Academy of Sciences, Wuhan
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Probing microheterogeneity in polymer systems via two-dimensional 129xenon NMR spy detection. A heterogeneous model blend system. Chem Phys Lett 1993. [DOI: 10.1016/0009-2614(93)89219-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Zhang S, Meier BH, Ernst RR. Local monitoring of proton spin diffusion in static and rotating samples via spy detection. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1993; 1:313-320. [PMID: 7834306 DOI: 10.1016/0926-2040(93)90013-d] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A method is described for investigating local proton "spin diffusion" by means of a 13C spin probe. The procedure does not require spectral resolution of proton resonance lines and can be applied in the laboratory frame of reference as well as in the rotating frame. Experimental results are presented for a static single crystal of ferrocene and for a powder sample under magic-angle spinning. The spin-diffusion rate constant is found to be proportional to the spinning speed in the range from 1 to 8 kHz.
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Affiliation(s)
- S Zhang
- Laboratorium für Physikalische Chemie, Eidgenössische Technische Hochschule, Zürich, Switzerland
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Moran LB, Berkowitz JK, Yesinowski JP. 19F and 31P magic-angle spinning nuclear magnetic resonance of antimony(III)-doped fluorapatite phosphors: Dopant sites and spin diffusion. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 45:5347-5360. [PMID: 10000252 DOI: 10.1103/physrevb.45.5347] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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40
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Kolodziejski W, He H, Klinowski J. 31P solid-state NMR study of spin diffusion in the molecular sieve VPI-5 using variable-speed MAS. Chem Phys Lett 1992. [DOI: 10.1016/0009-2614(92)85379-o] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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41
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Robyr P, Meier B, Ernst R. Tensor correlation by 2D spin-diffusion powder NMR spectroscopy: determination of the asymmetry of the hydrogenbond potential in benzoic acid. Chem Phys Lett 1991. [DOI: 10.1016/0009-2614(91)80285-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Levitt MH, Raleigh DP, Creuzet F, Griffin RG. Theory and simulations of homonuclear spin pair systems in rotating solids. J Chem Phys 1990. [DOI: 10.1063/1.458314] [Citation(s) in RCA: 354] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Pfleiderer B, Albert K, Lork KD, Unger KK, Brückner H, Bayer E. Korrelation des dynamischen Verhaltens vonn-Alkylliganden der stationären Phase mit den Retentionszeiten von Paracelsin-Peptiden bei der Reversed-Phase-HPLC. Angew Chem Int Ed Engl 1989. [DOI: 10.1002/ange.19891010321] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Blümich B, Spiess HW. Zweidimensionale Festkörper-NMR-Spektroskopie: Neue Möglichkeiten zur Untersuchung von Struktur und Dynamik fester Polymere. Angew Chem Int Ed Engl 1988. [DOI: 10.1002/ange.19881001207] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Etter MC, Hoye RC, Vojta GM. Solid-State NMR and X-Ray Crystallography: Complementary Tools for Structure Determination. CRYSTALLOGR REV 1988. [DOI: 10.1080/08893118808081683] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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