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72 results on '"Gaël De Paëpe"'

1. Solvent-derived defects suppress adsorption in MOF-74

Author: Yao Fu, Yifeng Yao, Alexander C. Forse, Jianhua Li, Kenji Mochizuki, Jeffrey R. Long, Jeffrey A. Reimer, Gaël De Paëpe, and Xueqian Kong
Subjects: Science
Abstract: Abstract Defects in metal-organic frameworks (MOFs) have great impact on their nano-scale structure and physiochemical properties. However, isolated defects are easily concealed when the frameworks are interrogated by typical characterization methods. In this work, we unveil the presence of solvent-derived formate defects in MOF-74, an important class of MOFs with open metal sites. With multi-dimensional solid-state nuclear magnetic resonance (NMR) investigations, we uncover the ligand substitution role of formate and its chemical origin from decomposed N,N-dimethylformamide (DMF) solvent. The placement and coordination structure of formate defects are determined by 13C NMR and density functional theory (DFT) calculations. The extra metal-oxygen bonds with formates partially eliminate open metal sites and lead to a quantitative decrease of N2 and CO2 adsorption with respect to the defect concentration. In-situ NMR analysis and molecular simulations of CO2 dynamics elaborate the adsorption mechanisms in defective MOF-74. Our study establishes comprehensive strategies to search, elucidate and manipulate defects in MOFs.
Published: 2023
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2. Optimizing chemistry at the surface of prodrug-loaded cellulose nanofibrils with MAS-DNP

Author: Akshay Kumar, Bastien Watbled, Isabelle Baussanne, Sabine Hediger, Martine Demeunynck, and Gaël De Paëpe
Subjects: Chemistry, QD1-999
Abstract: Functionalized nanocellulose is a promising drug carrier, however, studying surface functionalization at the atomic scale remains challenging due to spectroscopic methodology limitations. Here, the authors use dynamic nuclear polarization enhanced 13C and 15N solid-state NMR to optimize the drug loading on nanocellulose using aqueous heterogeneous chemistry.
Published: 2023
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3. Interfacial Ca2+ environments in nanocrystalline apatites revealed by dynamic nuclear polarization enhanced 43Ca NMR spectroscopy

Author: Daniel Lee, César Leroy, Charlène Crevant, Laure Bonhomme-Coury, Florence Babonneau, Danielle Laurencin, Christian Bonhomme, and Gaël De Paëpe
Subjects: Science
Abstract: Solid-state NMR can in principle be used to study calcium environments in biomaterials such as bones/teeth, but43Ca lacks receptivity. Here the authors present an approach to acquire 43Ca data for hydroxyapatite at its natural isotopic abundance, distinguishing between core and surface Ca sites.
Published: 2017
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4. Revealing Electrolytic Ion Sorption in Layered Graphene Galleries through Low-Temperature Solid-State NMR

Author: Daniel Lee, Harish Banda, Sandy Périé, Coralie Marcucci, Yves Chenavier, Lionel Dubois, Pierre-Louis Taberna, Patrice Simon, Gaël De Paëpe, and Florence Duclairoir
Subjects: General Chemical Engineering, Materials Chemistry, General Chemistry
Published: 2023
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5. PyrroTriPol: a semi-rigid trityl-nitroxide for high field dynamic nuclear polarization

Author: Thomas Halbritter, Rania Harrabi, Subhradip Paul, Johan van Tol, Daniel Lee, Sabine Hediger, Snorri Th. Sigurdsson, Frédéric Mentink-Vigier, and Gaël De Paëpe
Subjects: General Chemistry
Abstract: Magic angle spinning (MAS) dynamic nuclear polarization (DNP) has significantly broadened the scope of solid-state NMR to study biomolecular systems and materials. In recent years, the advent of very high field DNP combined with fast MAS has brought new challenges in the design of polarizing agents (PA) used to enhance nuclear spin polarization. Here, we present a trityl-nitroxide PA family based on a piperazine linker, named PyrroTriPol, for both aqueous and organic solutions. These new radicals have similar properties to that of TEMTriPol-I and can be readily synthesized, and purified in large quantities thereby ensuring widespread application. The family relies on a rigid bridge connecting the trityl and the nitroxide offering a better control of the electron spin-spin interactions thus providing improved performance across a broad range of magnetic fields and MAS frequencies while requiring reduced microwave power compared to bis-nitroxides. We demonstrate the efficiency of the PyrroTriPol family under a magnetic field of 9.4, 14.1 and 18.8 T with respect to TEMTriPol-I. In particular, the superiority of PyrroTriPol was demonstrated on γ-Al2O3 nanoparticles which enabled the acquisition of a high signal-to-noise surface-selective 27Al multiple-quantum MAS experiment at 18.8 T and 40 kHz MAS frequency
Published: 2023
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6. Sonocrystallization of CMONS Needles and Nanocubes: Mechanistic Studies and Advanced Crystallinity Characterization by Combining X-ray and Electron Diffractions with DNP-Enhanced NMR

Author: Xavier Cattoën, Akshay Kumar, Fabien Dubois, Carole Vaillant, Mauricio Matta-Seclén, Olivier Leynaud, Stéphanie Kodjikian, Sabine Hediger, Gaël De Paëpe, Alain Ibanez, Optique et Matériaux (NEEL - OPTIMA), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), X'Press : diffraction et hautes pressions (NEEL - X'Press), Optique & Microscopies (NEEL - POM), ANR-16-CE11-0030,TransPepNMR,Etude par RMN du complexe L,D-transpeptidase/peptidoglycan et de son influence sur la maturation de la paroi des mycobactéries(2016), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: Nanocrystallization, DNP-NMR, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Sonocrystallization, General Materials Science, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, Condensed Matter Physics, Fluorescence, Organic Nanocrystals
Abstract: International audience; This study introduces a new nanocrystallization method assisted by ultrasounds that produces needles or nanocubes of CMONS, a stilbene dye, with an excellent control over the polymorphism, and with a narrow size distribution. Owing to the production of radicals from dissolved dioxygen by high-intensity ultrasounds, trans-to-cis isomerization was observed in the absence of nitrogen bubbling, with the formation of two distinct crystalline phases for the different diastereomers. The crystallinity of CMONS needles was probed by various techniques, including X-ray and electron diffractions, fluorescence spectroscopy, and dynamic nuclear polarization (DNP) enhanced solid-state nuclear magnetic resonance. The latter was used to hyperpolarize 1 H nuclei and to record 1 H-13 C and 1 H-15 N CPMAS NMR spectra at natural isotopic abundance with very high signal-to-noise ratio. With such sensitivity, one can easily discriminate between cis and trans-I forms of CMONS, detect the presence of multiple polymorphic phases (even with minor contributions) and check the absence of amorphous phase. Finally, the mechanism involved in the formation of CMONS needles was ascertained after stabilizing intermediate nanocubes against Ostwald ripening and ordered aggregation mechanisms using the CTAB surfactant.
Published: 2022
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7. Fast magic angle spinning for the characterization of milligram quantities of organic and biological solids at natural isotopic abundance by 13C–13C correlation DNP-enhanced NMR

Author: Adam N. Smith, Rania Harrabi, Thomas Halbritter, Daniel Lee, Fabien Aussenac, Patrick C.A. van der Wel, Sabine Hediger, Snorri Th. Sigurdsson, Gaël De Paëpe, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), University of Iceland [Reykjavik], Bruker, University of Groningen [Groningen], Institut de Chimie Moléculaire de Grenoble (ICMG), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Solid-state nuclear magnetic resonance
Subjects: Dynamic Nuclear Polarization, Nuclear and High Energy Physics, Radiation, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Nuclear Magnetic Resonance, General Chemistry, MAS-DNP, Fast MAS, Pharmaceuticals, Instrumentation
Abstract: International audience; We show that multidimensional solid-state NMR 13C–13C correlation spectra of biomolecular assemblies and microcrystalline organic molecules can be acquired at natural isotopic abundance with only milligram quantities of sample. These experiments combine fast Magic Angle Spinning of the sample, low-power dipolar recoupling, and dynamic nuclear polarization performed with AsymPol biradicals, a recently introduced family of polarizing agents. Such experiments are essential for structural characterization as they provide short- and long-range distance information. This approach is demonstrated on diverse sample types, including polyglutamine fibrils implicated in Huntington's disease and microcrystalline ampicillin, a small antibiotic molecule.
Published: 2023
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8. Fast magic angle spinning for the characterization of milligram quantities of organic and biological solids at natural isotopic abundance by

Author: Adam N, Smith, Rania, Harrabi, Thomas, Halbritter, Daniel, Lee, Fabien, Aussenac, Patrick C A, van der Wel, Sabine, Hediger, Snorri Th, Sigurdsson, and Gaël, De Paëpe
Abstract: We show that multidimensional solid-state NMR
Published: 2022

9. Biomolecular and Biological Applications of Solid-State NMR with Dynamic Nuclear Polarization Enhancement

Author: Wing Ying Chow, Gaël De Paëpe, Sabine Hediger, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Groupe de RMN biomoléculaire (IBS-NMR), Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Centre National de la Recherche Scientifique (CNRS), and ANR-16-CE11-0030,TransPepNMR,Etude par RMN du complexe L,D-transpeptidase/peptidoglycan et de son influence sur la maturation de la paroi des mycobactéries(2016)
Subjects: [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Cell Nucleus, Magnetic Resonance Spectroscopy, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], General Chemistry, Magnetic Resonance Imaging, Nuclear Magnetic Resonance, Biomolecular
Abstract: International audience; Solid-state NMR spectroscopy (ssNMR) with magic-angle spinning (MAS) enables the investigation of biological systems within their native context, such as lipid membranes, viral capsid assemblies, and cells. However, such ambitious investigations often suffer from low sensitivity, due to the presence of significant amounts of other molecular species, which reduces the effective concentration of the biomolecule or interaction of interest. Certain investigations requiring the detection of very low concentration species remain unfeasible even with increasing experimental time for signal averaging. By applying dynamic nuclear polarization (DNP) to overcome the sensitivity challenge, the experimental time required can be reduced by orders of magnitude, broadening the feasible scope of applications for biological solid-state NMR. In this review, we outline strategies commonly adopted for biological applications of DNP, indicate ongoing 1 challenges, and present a comprehensive overview of biological investigations where MAS-DNP has led to unique insights.
Published: 2022
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10. Highly efficient polarizing agents for MAS‐DNP of proton‐dense molecular solids

Author: Rania Harrabi, Thomas Halbritter, Fabien Aussenac, Ons Dakhlaoui, Johan van Tol, Krishna K. Damodaran, Daniel Lee, Subhradip Paul, Sabine Hediger, Frederic Mentink‐Vigier, Snorri Th. Sigurdsson, Gaël De Paëpe, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Université Grenoble Alpes (UGA), University of Iceland [Reykjavik], Bruker BioSpin, GmbH, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), National High Magnetic Field Laboratory (NHMFL), Florida State University [Tallahassee] (FSU), and ANR-16-CE11-0030,TransPepNMR,Etude par RMN du complexe L,D-transpeptidase/peptidoglycan et de son influence sur la maturation de la paroi des mycobactéries(2016)
Subjects: [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Magnetic Resonance Spectroscopy, Pharmaceutical Preparations, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Electron Spin Resonance Spectroscopy, General Chemistry, General Medicine, Protons, Catalysis, Article
Abstract: International audience; Efficiently hyperpolarizing proton-dense molecular solids through Dynamic Nuclear Polarization (DNP) solid-state NMR is still an unmet challenge. Polarizing agents (PAs) developed so far do not perform well on proton-rich systems, such as organic microcrystals and biomolecular assemblies. Herein we introduce a new PA, cAsymPol-POK, and report outstanding hyperpolarization efficiency on 12.76 kDa U-$^{13}$ C,$^{15}$ N-labeled LecA protein and pharmaceutical drugs at high magnetic fields (up to 18.8 T) and fast MAS frequencies (up to 40 kHz). The performance of cAsymPol-POK is rationalized by MAS-DNP simulations combined with Electron Paramagnetic Resonance (EPR), Density Functional Theory (DFT) and Molecular Dynamics (MD). This work shows that this new biradical is compatible with challenging biomolecular applications and unlocks the rapid acquisition of $^{13}$C-$^{13}$ C and $^{15}$N-$^{13}$C correlations of pharmaceutical drugs at natural isotopic abundance, which are key experiments for structure determination.
Published: 2022
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11. ZnO Nanoplatelets with Controlled Thickness: Atomic Insight into Facet‐Specific Bimodal Ligand Binding Using DNP NMR

Author: Hanako Okuno, Janusz Lewiński, Michał Terlecki, Michał Leszczyński, Małgorzata Wolska-Pietkiewicz, Gaël De Paëpe, Stanislaw Gierlotka, Saumya Badoni, Iwona Justyniak, Daniel Lee, Faculty of Chemistry, Warsaw University of Technology, Faculty of Chemistry, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Warsaw University of Technology [Warsaw], Institute of Physical Chemistry, Polish Academy of Sciences, and Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA )
Subjects: Facet (geometry), Materials science, chemistry.chemical_element, 02 engineering and technology, Zinc, Nuclear magnetic resonance spectroscopy, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Biomaterials, Crystallography, chemistry, Electrochemistry, [CHIM]Chemical Sciences, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2021
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12. Detection of the Surface of Crystalline Y2O3 Using Direct 89Y Dynamic Nuclear Polarization

Author: Daniel Lee, Frédéric Blanc, Nick J. Brownbill, and Gaël De Paëpe
Subjects: Materials science, 010405 organic chemistry, Gyromagnetic ratio, Analytical chemistry, chemistry.chemical_element, Yttrium, 010402 general chemistry, Polarization (waves), 01 natural sciences, 7. Clean energy, 0104 chemical sciences, Magnetic field, NMR spectra database, chemistry, Magic angle spinning, General Materials Science, Hyperpolarization (physics), Physical and Theoretical Chemistry, Spectroscopy
Abstract: Nuclei with low gyromagnetic ratio (γ) present a serious sensitivity challenge for nulear magnetic resonance (NMR) spectroscopy. Recently, dynamic nuclear polarization (DNP) has shown great promise in overcoming this hurdle by indirect hyperpolarization (via 1H) of these low-γ nuclei. Here we show that at a magnetic field of 9.4 T and cryogenic temperature of about 110 K direct DNP of 89Y in a frozen solution of Y(NO3)3 can offer signal enhancements greater than 80 times using exogeneous trityl OX063 monoradical by satisfying the cross effect magic angle spinning (MAS) DNP mechanism. The large signal enhancement achieved permits 89Y NMR spectra of Y2O3 and Gd2O3-added Y2O3 materials to be obtained quickly (∼30 min), revealing a range of surface yttrium hydroxyl groups in addition to the two octahedral yttrium signals of the core. The results open up promises for the observation of low gyromagnetic ratio nuclei and the detection of corresponding surface and (sub-)surface sites.
Published: 2019
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13. De novo prediction of cross-effect efficiency for magic angle spinning dynamic nuclear polarization

Author: Johan van Tol, Sabine Hediger, Anne-Laure Barra, Gaël De Paëpe, Daniel Lee, Frederic Mentink-Vigier, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), National High Magnetic Field Laboratory (NHMFL), Florida State University [Tallahassee] (FSU), Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI-G ), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), FSU, Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: High-Field EPR, Materials science, Physics::Medical Physics, General Physics and Astronomy, 02 engineering and technology, Electron, 010402 general chemistry, DFT, 01 natural sciences, Molecular physics, Article, law.invention, Biradicals, depolarization, law, Magic angle spinning, Theory, Physical and Theoretical Chemistry, Electron paramagnetic resonance, Dynamic Nuclear Polarization, Cross effect, Nitroxides, [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], MAS-DNP, 021001 nanoscience & nanotechnology, Polarization (waves), 0104 chemical sciences, Solid-state nuclear magnetic resonance, Microwave irradiation, solid-state NMR, 0210 nano-technology, Microwave
Abstract: International audience; Magic angle spinning dynamic nuclear polarization (MAS-DNP) has become a key approach to boost the intrinsic low sensitivity of NMR in solids. This method relies on the use of both stable radicals as polarizing agents (PAs) and suitable high frequency microwave irradiation to hyperpolarize nuclei of interest. Relating PA chemical structure to DNP efficiency has been, and is still, a long-standing problem. The complexity of the polarization transfer mechanism has so far limited the impact of analytical derivation. However, recent numerical approaches have profoundly improved the basic understanding of the phenomenon and have now evolved to a point where they can be used to help design new PAs. In this work, the potential of advanced MAS-DNP simulations combined with DFT calculations and high-field EPR to qualitatively and quantitatively predict hyperpolarization efficiency of particular PAs is analyzed. This approach is demonstrated on AMUPol and TEKPol, two widely-used bis-nitroxide PAs. The results notably highlight how the PA structure and EPR characteristics affect the detailed shape of the DNP field profile. We also show that refined simulations of this profile using the orientation dependency of the electron spin-lattice relaxation times can be used to estimate the microwave B 1 field experienced by the sample. Finally, we show how modelling the nuclear spin-lattice relaxation times of close and bulk nuclei while accounting for PA concentration allows for a prediction of DNP enhancement factors and hyperpolarization build-up times.
Published: 2019
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14. The surface chemistry of a nanocellulose drug carrier unravelled by MAS-DNP

Author: Isabelle Baussanne, Daniel Lee, Sabine Hediger, Sébastien Fort, Cyril Balsollier, Akshay Kumar, Bastien Watbled, Julien Bras, Cécile Sillard, Naceur Belgacem, Gaël De Paëpe, Hippolyte Durand, Martine Demeunynck, Elisa Zeno, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Laboratoire Génie des procédés papetiers (LGP2), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA), Centre Technique du Papier (CTP), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Département de pharmacochimie moléculaire (DPM), Centre National de la Recherche Scientifique (CNRS), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: Conductometry, Chemistry(all), Nanotechnology, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, 3. Good health, Nanocellulose, chemistry.chemical_compound, Chemistry, Adsorption, chemistry, Covalent bond, Drug delivery, Surface modification, [CHIM]Chemical Sciences, Cellulose, 0210 nano-technology, Drug carrier
Abstract: Cellulose nanofibrils (CNF) are renewable bio-based materials with high specific area, which makes them ideal candidates for multiple emerging applications including for instance on-demand drug release. However, in-depth chemical and structural characterization of the CNF surface chemistry is still an open challenge, especially for low weight percentage of functionalization. This currently prevents the development of efficient, cost-effective and reproducible green synthetic routes and thus the widespread development of targeted and responsive drug-delivery CNF carriers. We show in this work how we use dynamic nuclear polarization (DNP) to overcome the sensitivity limitation of conventional solid-state NMR and gain insight into the surface chemistry of drug-functionalized TEMPO-oxidized cellulose nanofibrils. The DNP enhanced-NMR data can report unambiguously on the presence of trace amounts of TEMPO moieties and depolymerized cellulosic units in the starting material, as well as coupling agents on the CNFs surface (used in the heterogeneous reaction). This enables a precise estimation of the drug loading while differentiating adsorption from covalent bonding (∼1 wt% in our case) as opposed to other analytical techniques such as elemental analysis and conductometric titration that can neither detect the presence of coupling agents, nor differentiate unambiguously between adsorption and grafting. The approach, which does not rely on the use of 13C/15N enriched compounds, will be key to further develop efficient surface chemistry routes and has direct implication for the development of drug delivery applications both in terms of safety and dosage., DNP-enhanced solid-state NMR unravels the surface chemistry of functionalized nanocellulose.
Published: 2021
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15. Structural Fingerprinting of Protein Aggregates by Dynamic Nuclear Polarization-Enhanced Solid-State NMR at Natural Isotopic Abundance

Author: Ravindra Kodali, Patrick C.A. van der Wel, Jennifer C. Boatz, Irina Matlahov, Talia Piretra, Gaël De Paëpe, Adam N. Smith, Sabine Hediger, Katharina Märker, Magnetic Resonance [?-2019] (RM [?-2019]), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Magnetic Resonance (RM ), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), University of Pittsburgh School of Medicine, Pennsylvania Commonwealth System of Higher Education (PCSHE), and Duquesne University [Pittsburgh]
Subjects: 0301 basic medicine, Huntingtin, Protein Conformation, Mutant, Natural abundance, Protein aggregation, Fibril, Biochemistry, Catalysis, Isotopic labeling, Protein Aggregates, 03 medical and health sciences, Colloid and Surface Chemistry, Humans, [CHIM]Chemical Sciences, Particle Size, Polarization (electrochemistry), Nuclear Magnetic Resonance, Biomolecular, Carbon Isotopes, Huntingtin Protein, Nitrogen Isotopes, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Chemistry, Communication, General Chemistry, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], 030104 developmental biology, Solid-state nuclear magnetic resonance, Biophysics
Abstract: International audience; A pathological hallmark of Huntington's disease (HD) is the formation of neuronal protein deposits containing mutant huntingtin fragments with expanded polyglutamine (polyQ) domains. Prior studies have shown the strengths of solid-state NMR (ssNMR) to probe the atomic structure of such aggregates, but have required in vitro isotopic labeling. Herein, we present an approach for the structural fingerprinting of fibrils through ssNMR at natural isotopic abundance (NA). These methods will enable the spectroscopic fingerprinting of unlabeled (e.g., ex vivo) protein aggregates and the extraction of valuable new long-range 13 C− 13 C distance constraints
Published: 2018
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16. ZnO Nanoplatelets with Controlled Thickness: Atomic Insight into Facet‐Specific Bimodal Ligand Binding Using DNP NMR (Adv. Funct. Mater. 49/2021)

Author: Stanislaw Gierlotka, Michał Terlecki, Saumya Badoni, Hanako Okuno, Iwona Justyniak, Janusz Lewiński, Małgorzata Wolska-Pietkiewicz, Daniel Lee, Gaël De Paëpe, and Michał Leszczyński
Subjects: Biomaterials, Crystallography, Facet (geometry), Materials science, chemistry, Electrochemistry, chemistry.chemical_element, Nuclear magnetic resonance spectroscopy, Zinc, Condensed Matter Physics, Electronic, Optical and Magnetic Materials
Published: 2021
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17. Correction: De novo prediction of cross-effect efficiency for magic angle spinning dynamic nuclear polarization

Author: Frédéric Mentink-Vigier, Anne-Laure Barra, Johan van Tol, Sabine Hediger, Daniel Lee, and Gaël De Paëpe
Subjects: General Physics and Astronomy, Physical and Theoretical Chemistry
Abstract: Correction for ‘De novo prediction of cross-effect efficiency for magic angle spinning dynamic nuclear polarization’ by Frédéric Mentink-Vigier et al., Phys. Chem. Chem. Phys., 2019, 21, 2166–2176, DOI: 10.1039/C8CP06819D.
Published: 2021
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18. Solvent signal suppression for high-resolution MAS-DNP

Author: Daniel Lee, Sachin Rama Chaudhari, Gaël De Paëpe, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Lee, Daniel, Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: Nuclear and High Energy Physics, Analyte, Spins, 010405 organic chemistry, Chemistry, Dephasing, Biophysics, Analytical chemistry, 010402 general chemistry, Condensed Matter Physics, 01 natural sciences, Biochemistry, 0104 chemical sciences, Solvent, NMR spectra database, Solid-state nuclear magnetic resonance, Heteronuclear molecule, [CHIM] Chemical Sciences, Magic angle spinning, [CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS
Abstract: Dynamic nuclear polarization (DNP) has become a powerful tool to substantially increase the sensitivity of high-field magic angle spinning (MAS) solid-state NMR experiments. The addition of dissolved hyperpolarizing agents usually results in the presence of solvent signals that can overlap and obscure those of interest from the analyte. Here, two methods are proposed to suppress DNP solvent signals: a Forced Echo Dephasing experiment (FEDex) and TRAnsfer of Populations in DOuble Resonance Echo Dephasing (TRAPDORED) NMR. These methods reintroduce a heteronuclear dipolar interaction that is specific to the solvent, thereby forcing a dephasing of recoupled solvent spins and leaving acquired NMR spectra free of associated resonance overlap with the analyte. The potency of these methods is demonstrated on sample types common to MAS-DNP experiments, namely a frozen solution (of l-proline) and a powdered solid (progesterone), both containing deuterated glycerol as a DNP solvent. The proposed methods are efficient, simple to implement, compatible with other NMR experiments, and extendable past spectral editing for just DNP solvents. The sensitivity gains from MAS-DNP in conjunction with FEDex or TRAPDORED then permits rapid and uninterrupted sample analysis.
Published: 2017
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19. Disclosing Interfaces of ZnO Nanocrystals Using Dynamic Nuclear Polarization: Sol‐Gel versus Organometallic Approach

Author: Gaël De Paëpe, Małgorzata Wolska-Pietkiewicz, Janusz Lewiński, Agnieszka Grala, Daniel Lee, Saumya Badoni, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Faculty of Chemistry, Warsaw University of Technology, Warsaw University of Technology [Warsaw], Institute of Physical Chemistry, Polish Academy of Sciences, Faculty of Chemistry, Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)
Subjects: chemistry.chemical_classification, Materials science, 010405 organic chemistry, Ligand, chemistry.chemical_element, 02 engineering and technology, General Medicine, General Chemistry, Zinc, 021001 nanoscience & nanotechnology, 010402 general chemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Coordination complex, Crystallography, chemistry.chemical_compound, chemistry, Nanocrystal, Molecule, [CHIM]Chemical Sciences, 0210 nano-technology, Spectroscopy, Organometallic chemistry, Sol-gel
Abstract: International audience; The unambiguous characterization of the coordination chemistry of nanocrystal surfaces that have been produced by a wetchemical synthesis presently remains a highly challenging issue. Here, zinc oxide nanocrystals (ZnO NCs) coated by monoanionic diphenyl phosphate (DPP) ligands were derived by a traditional sol-gel process and a one-pot self-supporting organometallic (OSSOM) procedure, and advanced atomic-scale characterization through dynamic nuclear polarization (DNP-)enhanced solid-state nuclear magnetic resonance (ssNMR) spectroscopy has notably enabled resolving their vastly different surface-ligand interfaces. For the OSSOM-derived NCs, DPP moieties form stable and strongly-anchored µ2-and µ3-bridgingligand pairs that are resistant to competitive ligand exchange processes. Contrastingly, the sol-gel-derived NCs contain a wide variety of coordination modes of DPP ligands and a ligand exchange process takes place between DPP ligands and glycerol molecules. This highlights the power of DNP-enhanced ssNMR for detailed NC surface analysis and the superiority of the OSSOM approach for the preparation of high quality ZnO NCs.
Published: 2019
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20. Natural Isotopic Abundance 13C and 15N Multidimensional Solid-State NMR Enabled by Dynamic Nuclear Polarization

Author: Gaël De Paëpe, Katharina Märker, Sabine Hediger, Adam N. Smith, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Cambridge [UK] (CAM), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-15-IDEX-0002,UGA,IDEX UGA(2015), and ANR-16-CE11-0030,TransPepNMR,Etude par RMN du complexe L,D-transpeptidase/peptidoglycan et de son influence sur la maturation de la paroi des mycobactéries(2016)
Subjects: Dynamic Nuclear Polarization, dipolar recoupling, Distance constraints, Materials science, 010405 organic chemistry, Natural abundance, sensitivity enhancement, 010402 general chemistry, Polarization (waves), dipolar truncation, 01 natural sciences, 0104 chemical sciences, Magic angle spinning, correlation experiment, Solid-state nuclear magnetic resonance, Chemical physics, [CHIM]Chemical Sciences, General Materials Science, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; Dynamic nuclear polarization (DNP) has made feasible solid-state NMR experiments that were previously thought impractical due to sensitivity limitations. One such class of experiments is the structural characterization of organic and biological samples at natural isotopic abundance (NA). Herein, we describe the many advantages of DNP-enabled ssNMR at NA, including the extraction of long-range distance constraints using dipolar recoupling pulse sequences without the deleterious effects of dipolar truncation. In addition to the theoretical underpinnings in the analysis of these types of experiments, numerous applications of DNPenabled ssNMR at NA are discussed.
Published: 2019
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21. Natural Isotopic Abundance

Author: Adam N, Smith, Katharina, Märker, Sabine, Hediger, and Gaël, De Paëpe
Abstract: Dynamic nuclear polarization (DNP) has made feasible solid-state NMR experiments that were previously thought impractical due to sensitivity limitations. One such class of experiments is the structural characterization of organic and biological samples at natural isotopic abundance (NA). Herein, we describe the many advantages of DNP-enabled ssNMR at NA, including the extraction of long-range distance constraints using dipolar recoupling pulse sequences without the deleterious effects of dipolar truncation. In addition to the theoretical underpinnings in the analysis of these types of experiments, numerous applications of DNP-enabled ssNMR at NA are discussed.
Published: 2019

22. Detection of the Surface of Crystalline Y

Author: Nick J, Brownbill, Daniel, Lee, Gaël, De Paëpe, and Frédéric, Blanc
Abstract: [Image: see text] Nuclei with low gyromagnetic ratio (γ) present a serious sensitivity challenge for nulear magnetic resonance (NMR) spectroscopy. Recently, dynamic nuclear polarization (DNP) has shown great promise in overcoming this hurdle by indirect hyperpolarization (via (1)H) of these low-γ nuclei. Here we show that at a magnetic field of 9.4 T and cryogenic temperature of about 110 K direct DNP of (89)Y in a frozen solution of Y(NO(3))(3) can offer signal enhancements greater than 80 times using exogeneous trityl OX063 monoradical by satisfying the cross effect magic angle spinning (MAS) DNP mechanism. The large signal enhancement achieved permits (89)Y NMR spectra of Y(2)O(3) and Gd(2)O(3)-added Y(2)O(3) materials to be obtained quickly (∼30 min), revealing a range of surface yttrium hydroxyl groups in addition to the two octahedral yttrium signals of the core. The results open up promises for the observation of low gyromagnetic ratio nuclei and the detection of corresponding surface and (sub-)surface sites.
Published: 2019

23. Sparsely Pillared Graphene Materials for High-Performance Supercapacitors: Improving Ion Transport and Storage Capacity

Author: Florence Duclairoir, Lionel Dubois, Barbara Daffos, Pierre-Louis Taberna, Gaël De Paëpe, Olivier Crosnier, Harish Banda, Patrice Simon, Sandy Périé, Daniel Lee, Commissariat à l'Energie Atomique et aux énergies alternatives - CEA (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Collège de France (FRANCE), Ecole Nationale Supérieure de Chimie de Paris - ENSCP (FRANCE), Ecole Nationale Supérieure de Chimie de Montpellier - ENSCM (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut polytechnique de Grenoble (FRANCE), Sorbonne Université (FRANCE), Université Grenoble Alpes - UGA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Nantes (FRANCE), Université de Picardie Jules Verne (FRANCE), Université de Pau et des Pays de l'Adour - UPPA (FRANCE), Université de Haute Alsace - UHA (FRANCE), Université de Montpellier (FRANCE), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Conception d’Architectures Moléculaires et Processus Electroniques (CAMPE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Fédérale Toulouse Midi-Pyrénées, Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Magnetic Resonance (RM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Université de Nantes (UN)-Université de Nantes (UN)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Institut National Polytechnique de Toulouse - INPT (FRANCE)
Subjects: Energie électrique, Materials science, Matériaux, Oxide, General Physics and Astronomy, Pillared graphene, Nanotechnology, 02 engineering and technology, 010402 general chemistry, Electrochemistry, 01 natural sciences, Article, [SPI.MAT]Engineering Sciences [physics]/Materials, law.invention, chemistry.chemical_compound, Interlayer galleries, Graphene hydrogel, law, Supercapacitors, [CHIM]Chemical Sciences, Molecule, General Materials Science, Bifunctional, ComputingMilieux_MISCELLANEOUS, Supercapacitor, Graphene, [SPI.NRJ]Engineering Sciences [physics]/Electric power, General Engineering, Ion sieving, Sorption, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, Covalent bond, 0210 nano-technology
Abstract: International audience; Graphene-based materials are extensively studied as promising candidates for supercapacitors (SCs) owing to the high surface area, electrical conductivity, and mechanical flexibility of graphene. Reduced graphene oxide (RGO), a close graphene-like material studied for SCs, offers limited specific capacitances (100 F·g–1) as the reduced graphene sheets partially restack through π–π interactions. This paper presents pillared graphene materials designed to minimize such graphitic restacking by cross-linking the graphene sheets with a bifunctional pillar molecule. Solid-state NMR, X-ray diffraction, and electrochemical analyses reveal that the synthesized materials possess covalently cross-linked graphene galleries that offer additional sites for ion sorption in SCs. Indeed, high specific capacitances in SCs are observed for the graphene materials synthesized with an optimized number of pillars. Specifically, the straightforward synthesis of a graphene hydrogel containing pillared structures and an interconnected porous network delivered a material with gravimetric capacitances two times greater than that of RGO (200 F·g–1vs 107 F·g–1) and volumetric capacitances that are nearly four times larger (210 F·cm–3vs 54 F·cm–3). Additionally, despite the presence of pillars inside the graphene galleries, the optimized materials show efficient ion transport characteristics. This work therefore brings perspectives for the next generation of high-performance SCs.
Published: 2019
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24. Ultra-low temperature MAS-DNP

Author: Eric Bouleau, Gaël De Paëpe, Daniel Lee, Pierre Saint-Bonnet, Sabine Hediger, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Calculs et Conception Cryogénique (L3C ), Service des Basses Températures (SBT ), Laboratoire de Cryogénie pour la Fusion (LCF ), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-08-CEXC-0003,DNP4NanoCarac,Polarisation Dynamique Nucléaire : amélioration de la sensibilité en RMN solide haute résolution pour l'étude structurale 3D de nanotubes fonctionnalisés et autres nano-objets(2008), ANR-12-BS08-0016,CryoMAS4DNP,Polarisation dynamique nucléaire en rotation à l'angle magique à très basse température et à haut champ magnétique(2012), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Cryostat, Nuclear and High Energy Physics, Magic angle, Enhanced NMR, Biophysics, Analytical chemistry, 010402 general chemistry, Solid-state NMR, 01 natural sciences, Biochemistry, Dynamic nuclear polarization, Magic angle spinning, Helium sample spinning, C-13 NMR, Spectroscopy, Spinning, [PHYS]Physics [physics], Physics, Spins, 010405 organic chemistry, business.industry, Atmospheric temperature range, Condensed Matter Physics, 0104 chemical sciences, Cryogenic helium, Solid-state nuclear magnetic resonance, C-13-C-13 correlation spectroscopy, Optoelectronics, business
Abstract: International audience; Since the infancy of NMR spectroscopy, sensitivity and resolution have been the limiting factors of the technique. Regular essential developments on this front have led to the widely applicable, versatile, and powerful spectroscopy that we know today. However, the Holy Grail of ultimate sensitivity and resolution is not yet reached, and technical improvements are still ongoing. Hence, high-field dynamic nuclear polarization (DNP) making use of high-frequency, high-power microwave irradiation of electron spins has become very promising in combination with magic angle sample spinning (MAS) solid-state NMR experiments. This is because it leads to a transfer of the much larger polarization of these electron spins under suitable irradiation to surrounding nuclei, greatly increasing NMR sensitivity. Currently, this boom in MAS-DNP is mainly performed at minimum sample temperatures of about 100 K, using cold nitrogen gas to pneumatically spin and cool the sample. This Perspective deals with the desire to improve further the sensitivity and resolution by providing "ultra"-low temperatures for MAS-DNP, using cryogenic helium gas. Different designs on how this technological challenge has been overcome are described. It is shown that stable and fast spinning can be attained for sample temperatures down to 30 K using a large cryostat developed in our laboratory. Using this cryostat to cool a closed-loop of helium gas brings the additional advantage of sample spinning frequencies that can greatly surpass those achievable with nitrogen gas, due to the differing fluidic properties of these two gases. It is shown that using ultra-low temperatures for MAS-DNP results in substantial experimental sensitivity enhancements and according time-savings. Access to this temperature range is demonstrated to be both viable and highly pertinent. (C) 2015 Elsevier Inc. All rights reserved.
Published: 2016
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25. High-Field Solid-State NMR with Dynamic Nuclear Polarization

Author: Sabine Hediger, Gaël De Paëpe, Daniel Lee, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: Materials science, Carbon-13 NMR satellite, 010405 organic chemistry, Nuclear magnetic resonance spectroscopy, Fluorine-19 NMR, Nuclear magnetic resonance crystallography, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Solid-state nuclear magnetic resonance, Chemical physics, [CHIM]Chemical Sciences, Hyperpolarization (physics), Insensitive nuclei enhanced by polarization transfer, ComputingMilieux_MISCELLANEOUS, Earth's field NMR
Abstract: International audience
Published: 2018
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26. Interfacial Ca2+ environments in nanocrystalline apatites revealed by dynamic nuclear polarization enhanced 43Ca NMR spectroscopy

Author: Gaël De Paëpe, Christian Bonhomme, César Leroy, Danielle Laurencin, Florence Babonneau, Daniel Lee, Charlène Crevant, Laure Bonhomme-Coury, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Spectroscopie, Modélisation, Interfaces pour L'Environnement et la Santé (LCMCP-SMiLES), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), ERC-CoG-2015, No. 682895, ANR-12-BS08-0016-01, Labex ARCANE (ANR-11-LABX-0003-01), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-12-BS08-0016,CryoMAS4DNP,Polarisation dynamique nucléaire en rotation à l'angle magique à très basse température et à haut champ magnétique(2012), European Project: 682895, Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)
Subjects: Materials science, Science, General Physics and Astronomy, Natural abundance, 010402 general chemistry, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Apatite, Polarization (electrochemistry), Multidisciplinary, Isotope, 010405 organic chemistry, fungi, biomaterial, Biomaterial, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, Nuclear magnetic resonance spectroscopy, 43Ca, Nanocrystalline material, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, NMR spectra database, Chemical physics, apatite, visual_art, visual_art.visual_art_medium, DNP
Abstract: The interfaces within bones, teeth and other hybrid biomaterials are of paramount importance but remain particularly difficult to characterize at the molecular level because both sensitive and selective techniques are mandatory. Here, it is demonstrated that unprecedented insights into calcium environments, for example the differentiation of surface and core species of hydroxyapatite nanoparticles, can be obtained using solid-state NMR, when combined with dynamic nuclear polarization. Although calcium represents an ideal NMR target here (and de facto for a large variety of calcium-derived materials), its stable NMR-active isotope, calcium-43, is a highly unreceptive probe. Using the sensitivity gains from dynamic nuclear polarization, not only could calcium-43 NMR spectra be obtained easily, but natural isotopic abundance 2D correlation experiments could be recorded for calcium-43 in short experimental time. This opens perspectives for the detailed study of interfaces in nanostructured materials of the highest biological interest as well as calcium-based nanosystems in general.
Published: 2017
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27. At the very beginning of life on Earth: the thiol-rich peptide (TRP) world hypothesis

Author: Anne Milet, Ibrahim Shalayel, K. V. Raghavendra Rao, Kieu Dung Ly, Yannick Vallée, Gaël De Paëpe, Katharina Märker, Département de Chimie Moléculaire - Synthèse Et Réactivité en Chimie Organique (DCM - SeRCO ), Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE ), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE )
Subjects: 0301 basic medicine, Embryology, Earth, Planet, Origin of Life, Peptide, Tripeptide, Biology, 03 medical and health sciences, chemistry.chemical_compound, Abiogenesis, Thiolactone, Humans, Sulfhydryl Compounds, Amino Acids, Beginning of Human Life, [SDV.BDD]Life Sciences [q-bio]/Development Biology, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Condensation reaction, Combinatorial chemistry, Peptide Fragments, Amino acid, 030104 developmental biology, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Biochemistry, Nucleic acid, Developmental Biology, Cysteine
Abstract: Life developed on Earth probably about 3.8 billion years ago, on a planet that was already largely covered by oceans and where the atmosphere was very humid. The reactions, which may have led to the formation of the first polymers, particularly to the first peptides and nucleic acids, must have been compatible with these conditions. This is the case of the reaction of nitriles with aminothiols, such as cysteine and homocysteine. Since aminonitriles are the probable precursors of amino acids, this condensation reaction has been able to rapidly yield dipeptides, tripeptides, oligomers and even true polymers, each containing thiol functions. These thiol-rich peptides (TRP's) would then have assumed the various catalytic roles that the peptides containing cysteine residues play today. They allowed a rapid bloom of life in the primitive ocean. In this scenario, RNA's are not the first polymers, but have been synthesized, like DNA's, thanks to the catalytic properties of thiols in a mostly TRP world. In this world, due to its ability to form a thiolactone, homocysteine may have played the leading role in enabling the previously formed oligomers to be stappled together, thus accelerating the formation of long peptide chains.
Published: 2017
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28. Welcoming natural isotopic abundance in solid-state NMR: probing π-stacking and supramolecular structure of organic nanoassemblies using DNP

Author: Daniel Lee, Katharina Märker, Subhradip Paul, Gaël De Paëpe, Sabine Hediger, Carlos Fernández‐de‐Alba, Jean-Marie Mouesca, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Magnetic Resonance (RM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Centre National de la Recherche Scientifique (CNRS)
Subjects: 010405 organic chemistry, Stereochemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Intermolecular force, Supramolecular chemistry, Stacking, Molecular electronics, General Chemistry, Crystal structure, Nuclear magnetic resonance crystallography, 010402 general chemistry, 01 natural sciences, 3. Good health, 0104 chemical sciences, Chemistry, chemistry.chemical_compound, Solid-state nuclear magnetic resonance, chemistry, Chemical physics, [CHIM]Chemical Sciences, Diphenylalanine, ComputingMilieux_MISCELLANEOUS
Abstract: The low natural abundance of 13C combined with MAS-DNP enables 13C–13C polarization transfer up to ∼7 Å and observation of π-stacking., The self-assembly of small organic molecules is an intriguing phenomenon, which provides nanoscale structures for applications in numerous fields from medicine to molecular electronics. Detailed knowledge of their structure, in particular on the supramolecular level, is a prerequisite for the rational design of improved self-assembled systems. In this work, we prove the feasibility of a novel concept of NMR-based 3D structure determination of such assemblies in the solid state. The key point of this concept is the deliberate use of samples that contain 13C at its natural isotopic abundance (NA, 1.1%), while exploiting magic-angle spinning dynamic nuclear polarization (MAS-DNP) to compensate for the reduced sensitivity. Since dipolar truncation effects are suppressed to a large extent in NA samples, unique and highly informative spectra can be recorded which are impossible to obtain on an isotopically labeled system. On the self-assembled cyclic diphenylalanine peptide, we demonstrate the detection of long-range internuclear distances up to ∼7 Å, allowing us to observe π-stacking through 13C–13C correlation spectra, providing a powerful tool for the analysis of one of the most important non-covalent interactions. Furthermore, experimental polarization transfer curves are in remarkable agreement with numerical simulations based on the crystallographic structure, and can be fully rationalized as the superposition of intra- and intermolecular contributions. This new approach to NMR crystallography provides access to rich and precise structural information, opening up a new avenue to de novo crystal structure determination by NMR.
Published: 2017
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29. Efficient 2D double-quantum solid-state NMR spectroscopy with large spectral widths

Author: Katharina Märker, Sabine Hediger, Gaël De Paëpe, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Distance constraints, Mathematics::Functional Analysis, Chemistry, Metals and Alloys, Analytical chemistry, Phase (waves), 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Molecular physics, Catalysis, Spectral line, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Solid-state nuclear magnetic resonance, Materials Chemistry, Ceramics and Composites, Double quantum, 0210 nano-technology, Spectroscopy
Abstract: International audience; 2D double-quantum single-quantum correlation spectra with arbitrary spectral widths can be recorded with SR26 and related supercycled recoupling sequences when applying Supercycle-Timing-Compensation (STiC) phase shifts. This concept widely extends the applicability of supercycled sequences, most importantly for obtaining long-range distance constraints for structure determination with solid-state NMR.
Published: 2017
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30. Efficient cross-effect dynamic nuclear polarization without depolarization in high-resolution MAS NMR

Author: Anne-Laure Barra, Gaël De Paëpe, Guinevere Mathies, Frederic Mentink-Vigier, Sabine Hediger, Yangping Liu, Daniel Lee, Robert G. Griffin, Marc A. Caporini, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), MIT - Francis Bitter Magnet Lab, Massachusetts Institute of Technology (MIT), Tianjin University (TJU), Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI-G ), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Bruker BioSpin [Billerica, MA], Centre National de la Recherche Scientifique (CNRS), ANR-12-BS08-0016,CryoMAS4DNP,Polarisation dynamique nucléaire en rotation à l'angle magique à très basse température et à haut champ magnétique(2012), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-10-EQPX-0047,SENS,RMN de Surface Exalté par Polarisation Dynamique Nucléaire(2010), European Project: 682895, Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Cross effect, 010405 organic chemistry, Chemistry, [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], Analytical chemistry, High resolution, Natural abundance, Depolarization, General Chemistry, 010402 general chemistry, Polarization (waves), 01 natural sciences, 0104 chemical sciences, Magnetic field, Atomic resolution, Chemical physics, ddc:540, Spinning, ComputingMilieux_MISCELLANEOUS
Abstract: The mixed trityl-TEMPO biradical TEMTriPol-1 provides excellent MAS NMR sensitivity with DNP while avoiding nuclear depolarization., Dynamic nuclear polarization (DNP) has the potential to enhance the sensitivity of magic-angle spinning (MAS) NMR by many orders of magnitude and therefore to revolutionize atomic resolution structural analysis. Currently, the most widely used approach to DNP for studies of chemical, material, and biological systems involves the cross-effect (CE) mechanism, which relies on biradicals as polarizing agents. However, at high magnetic fields (≥5 T), the best biradicals used for CE MAS-DNP are still far from optimal, primarily because of the nuclear depolarization effects they induce. In the presence of bisnitroxide biradicals, magic-angle rotation results in a reverse CE that can deplete the initial proton Boltzmann polarization by more than a factor of 2. In this paper we show that these depolarization losses can be avoided by using a polarizing agent composed of a narrow-line trityl radical tethered to a broad-line TEMPO. Consequently, we show that a biocompatible trityl-nitroxide biradical, TEMTriPol-1, provides the highest MAS NMR sensitivity at ≥10 T, and its relative efficiency increases with the magnetic field strength. We use numerical simulations to explain the absence of depolarization for TEMTriPol-1 and its high efficiency, paving the way for the next generation of polarizing agents for DNP. We demonstrate the superior sensitivity enhancement using TEMTriPol-1 by recording the first solid-state 2D 13C–13C correlation spectrum at natural isotopic abundance at a magnetic field of 18.8 T.
Published: 2017
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31. Primostrato Solid-State NMR Enhanced by Dynamic Nuclear Polarization: Pentacoordinated Al3+ Ions Are Only Located at the Surface of Hydrated γ-Alumina

Author: Olivier Lafon, Nghia Tuan Duong, Gaël De Paëpe, Daniel Lee, Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Subjects: Chemistry, Catalyst support, Analytical chemistry, Nuclear magnetic resonance spectroscopy, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Ion, Catalysis, General Energy, Solid-state nuclear magnetic resonance, Chemical physics, Magic angle spinning, [CHIM]Chemical Sciences, Sample preparation, Physical and Theoretical Chemistry, Polarization (electrochemistry), ComputingMilieux_MISCELLANEOUS
Abstract: Aluminas (Al2O3) are ubiquitous functional materials. In particular, the γ-alumina form is extensively used in research and industry as a catalyst and catalyst support. Nevertheless, a full structural description, which would aid in comprehension of its properties, is lacking and under large debate. Solid-state NMR has been used previously to study γ-alumina but is limited for certain applications, such as surface studies, due to intrinsic low sensitivity. Here, we detail the implementation of low temperature (∼100 K) magic angle spinning combined with dynamic nuclear polarization (MAS-DNP) to significantly enhance the sensitivity of solid-state NMR experiments and gain structural insights into this important material. Notably, we analyze hydrophilic and hydrophobic sample preparation protocols and their implications on the sample and resulting NMR parameters. We show that the choice of preparation does not perturb the spectrum, but it does have a large effect on NMR coherence lifetimes, as does the corre...
Published: 2014
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32. Dynamic Nuclear Polarization NMR of Low-γ Nuclei: Structural Insights into Hydrated Yttrium-Doped BaZrO3

Author: Clare P. Grey, Luke Sperrin, Sossina M. Haile, Frédéric Blanc, Gaël De Paëpe, Yoshihiro Yamazaki, Daniel Lee, and Riza Dervisoglu
Subjects: Chemistry, Gyromagnetic ratio, chemistry.chemical_element, Yttrium, Polarization (waves), Zirconate, NMR spectra database, Nuclear magnetic resonance, Solid-state nuclear magnetic resonance, Magic angle spinning, Proton NMR, Physical chemistry, General Materials Science, Physical and Theoretical Chemistry
Abstract: We demonstrate that solid-state NMR spectra of challenging nuclei with a low gyromagnetic ratio such as yttrium-89 can be acquired quickly with indirect dynamic nuclear polarization (DNP) methods. Proton to ^(89)Y cross polarization (CP) magic angle spinning (MAS) spectra of Y^(3+) in a frozen aqueous solution were acquired in minutes using the AMUPol biradical as a polarizing agent. Subsequently, the detection of the ^(89)Y and 1H NMR signals from technologically important hydrated yttrium-doped zirconate ceramics, in combination with DFT calculations, allows the local yttrium and proton environments present in these protonic conductors to be detected and assigned to different hydrogen-bonded environments.
Published: 2014
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33. Optimization of an absolute sensitivity in a glassy matrix during DNP-enhanced multidimensional solid-state NMR experiments

Author: Sabine Hediger, Anne-Laure Barra, Vincent Maurel, Hiroki Takahashi, Carlos Fernández‐de‐Alba, Serge Gambarelli, Gaël De Paëpe, Michel Bardet, Daniel Lee, Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI-G), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Université Joseph Fourier - Grenoble 1 (UJF)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear and High Energy Physics, 010405 organic chemistry, Chemistry, Physics::Medical Physics, Biophysics, Analytical chemistry, Electron, 010402 general chemistry, Condensed Matter Physics, Polarization (waves), 01 natural sciences, Biochemistry, Spectral line, 0104 chemical sciences, law.invention, Magnetization, Solid-state nuclear magnetic resonance, law, [CHIM]Chemical Sciences, Glass transition, Electron paramagnetic resonance, ComputingMilieux_MISCELLANEOUS, Microwave
Abstract: Thanks to instrumental and theoretical development, notably the access to high-power and high-frequency microwave sources, high-field dynamic nuclear polarization (DNP) on solid-state NMR currently appears as a promising solution to enhance nuclear magnetization in many different types of systems. In magic-angle-spinning DNP experiments, systems of interest are usually dissolved or suspended in glass-forming matrices doped with polarizing agents and measured at low temperature (down to ∼100K). In this work, we discuss the influence of sample conditions (radical concentration, sample temperature, etc.) on DNP enhancements and various nuclear relaxation times which affect the absolute sensitivity of DNP spectra, especially in multidimensional experiments. Furthermore, DNP-enhanced solid-state NMR experiments performed at 9.4 T are complemented by high-field CW EPR measurements performed at the same magnetic field. Microwave absorption by the DNP glassy matrix is observed even below the glass transition temperature caused by softening of the glass. Shortening of electron relaxation times due to glass softening and its impact in terms of DNP sensitivity is discussed.
Published: 2014
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34. Application of 7Li NMR to characterize the evolution of intercalated and non-intercalated lithium in LiFePO4-based materials for Li-ion batteries

Author: Sébastien Patoux, Guillaume Gerbaud, Sabine Hediger, Michel Bardet, Gaël De Paëpe, Carole Bourbon, and Anton Buzlukov
Subjects: Materials science, Lithium vanadium phosphate battery, Lithium iron phosphate, Inorganic chemistry, chemistry.chemical_element, Electrolyte, Condensed Matter Physics, Electrochemistry, Cathode, law.invention, chemistry.chemical_compound, Solid-state nuclear magnetic resonance, chemistry, law, General Materials Science, Lithium, Grain boundary, Electrical and Electronic Engineering
Abstract: Different synthesis batches of LiFePO4/C materials were prepared, and their electrochemical properties as positive cathodes for lithium-ion batteries were evaluated. Using standard solid-state NMR conditions, such as a 7-mm magic-angle-spinning probe performing at low spinning rates, information on both intercalated and non-intercalated (stored on the grain boundaries) lithium was obtained. A sharp signal assigned to non-intercalated lithium could be observed by diluting the active material in silica. Correlations could be, thus, obtained between the amount of each type of lithium and the electrochemical history and state of the material, revealing that the relative amount of surface lithium in a pristine LiFePO4/C material is rather constant and cannot be used as a criterion for its further specification. However, a drastic increase of this surface lithium was observed in the cathode materials of out-of-order batteries. As the cathode material recovered from the batteries after electrochemical testing was carefully washed before analysis, we can conclude that the non-intercalated lithium is strongly bound to the active material probably inside the so-called solid electrolyte interface layer at the surfaces of LiFePO4 particles. This work illustrates that solid-state lithium NMR can allow rapid characterization and testing of LiFePO4/C cathode materials.
Published: 2013
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35. Interfacial Ca

Author: Daniel, Lee, César, Leroy, Charlène, Crevant, Laure, Bonhomme-Coury, Florence, Babonneau, Danielle, Laurencin, Christian, Bonhomme, and Gaël, De Paëpe
Subjects: Article
Abstract: The interfaces within bones, teeth and other hybrid biomaterials are of paramount importance but remain particularly difficult to characterize at the molecular level because both sensitive and selective techniques are mandatory. Here, it is demonstrated that unprecedented insights into calcium environments, for example the differentiation of surface and core species of hydroxyapatite nanoparticles, can be obtained using solid-state NMR, when combined with dynamic nuclear polarization. Although calcium represents an ideal NMR target here (and de facto for a large variety of calcium-derived materials), its stable NMR-active isotope, calcium-43, is a highly unreceptive probe. Using the sensitivity gains from dynamic nuclear polarization, not only could calcium-43 NMR spectra be obtained easily, but natural isotopic abundance 2D correlation experiments could be recorded for calcium-43 in short experimental time. This opens perspectives for the detailed study of interfaces in nanostructured materials of the highest biological interest as well as calcium-based nanosystems in general., Solid-state NMR can in principle be used to study calcium environments in biomaterials such as bones/teeth, but 43Ca lacks receptivity. Here the authors present an approach to acquire 43Ca data for hydroxyapatite at its natural isotopic abundance, distinguishing between core and surface Ca sites.
Published: 2016

36. Enhanced Solid-State NMR Correlation Spectroscopy of Quadrupolar Nuclei Using Dynamic Nuclear Polarization

Author: Jean-Philippe Dacquin, Daniel Lee, Michel Bardet, Gaël De Paëpe, Aany Sofia Lilly Thankamony, Hiroki Takahashi, Olivier Lafon, Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille
Subjects: Magnetic Resonance Spectroscopy, Surface Properties, Analytical chemistry, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, Spectral line, Colloid and Surface Chemistry, Aluminum Oxide, [CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS, 010405 organic chemistry, Chemistry, General Chemistry, Nuclear magnetic resonance spectroscopy, Reference Standards, Polarization (waves), 0104 chemical sciences, Magnetic field, Dipole, Solid-state nuclear magnetic resonance, Mesoporous material, Porosity, Two-dimensional nuclear magnetic resonance spectroscopy, Aluminum
Abstract: By means of a true sensitivity enhancement for a solid-state NMR spectroscopy (SSNMR) experiment performed under dynamic nuclear polarization (DNP) conditions, corresponding to 4-5 orders of magnitude of time savings compared with a conventional SSNMR experiment, it is shown that it is possible to record interface-selective (27)Al-(27)Al two-dimensional dipolar correlation spectra on mesoporous alumina, an advanced material with potential industrial applications. The low efficiency of cross-polarization and dipolar recoupling for quadrupolar nuclei is completely negated using this technique. The important presence of pentacoordinated Al has not only been observed, but its role in bridging interfacial tetra- and hexacoordinated Al has been determined. Such structural information, collected at low temperature (∼103 K) and 9.4 T with the use of DNP, would have been impossible to obtain under standard conditions, even using a higher magnetic field. However, here it is demonstrated that this information can be obtained in only 4 h. This work clearly opens a new avenue for the application of SSNMR to quadrupolar nuclei and notably the atomic-scale structure determination of catalysis materials such as mesoporous alumina.
Published: 2012
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37. Rapid Natural-Abundance 2D13C-13C Correlation Spectroscopy Using Dynamic Nuclear Polarization Enhanced Solid-State NMR and Matrix-Free Sample Preparation

Author: Lionel Dubois, Daniel Lee, Michel Bardet, Hiroki Takahashi, Sabine Hediger, Gaël De Paëpe, Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)
Subjects: 010405 organic chemistry, Chemistry, Abundance (chemistry), Analytical chemistry, General Medicine, General Chemistry, Fluorine-19 NMR, Nuclear magnetic resonance spectroscopy, 010402 general chemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Matrix (chemical analysis), Solid-state nuclear magnetic resonance, [CHIM]Chemical Sciences, Sample preparation, Polarization (electrochemistry), Two-dimensional nuclear magnetic resonance spectroscopy, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2012
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38. Dynamics property recovery of archaeological-wood fibers treated with polyethylene glycol demonstrated by high-resolution solid-state NMR

Author: Mathilde Giffard, Guillaume Gerbaud, Châu Doan, Sabine Hediger, Michel Bardet, Gaël De Paëpe, and Quôc-Khôi Trân
Subjects: chemistry.chemical_classification, Materials science, Polymers and Plastics, technology, industry, and agriculture, Polymer, Polyethylene glycol, Carbon-13 NMR, Archaeology, NMR spectra database, chemistry.chemical_compound, Molecular dynamics, Solid-state nuclear magnetic resonance, chemistry, PEG ratio, Cellulose
Abstract: We used high-resolution Solid-State 13C NMR to better understand and optimize the conservation process of archaeological waterlogged woods by polyethylene glycol (PEG) impregnation via the study of the molecular interactions between PEG and residual celluloses. By both deconvoluting NMR spectra and analyzing the behavior of 13C magnetization build-up under proton to carbon cross-polarization conditions, we were able to quantify PEG penetration and extract parameters sensitive to molecular dynamics such as proton spin lattice-relaxation-time constants in the rotating frame T1ρH and the cross-relaxation time constant TCH. By exploring a large range of PEG concentrations for the impregnating solutions we show that the PEG penetrates inside the fibers and interacts at a molecular level with the cellulose fibrils thus restoring the dynamics properties of the damaged molecular cell wall network. At high PEG concentration, the polymer accumulates in the remaining free volume with more and looser molecular interactions with the residual wood components. This feature explains the facility for these hydroscopic materials to exude from the wood and led to deleterious consequences for the restored artefacts.
Published: 2012
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39. High-Resolution Solid-State NMR Structure of a 17.6 kDa Protein

Author: Ivano Bertini, Gaël De Paëpe, Moreno Lelli, Anusarka Bhaumik, Józef R. Lewandowski, Claudio Luchinat, and Robert G. Griffin
Subjects: Models, Molecular, Magnetic Resonance Spectroscopy, Protein Conformation, Chemistry, Metal ions in aqueous solution, Resolution (electron density), General Chemistry, Nuclear magnetic resonance spectroscopy, Crystallography, X-Ray, Biochemistry, Article, Catalysis, NMR spectra database, Paramagnetism, Crystallography, Colloid and Surface Chemistry, Protein structure, Solid-state nuclear magnetic resonance, Matrix Metalloproteinase 12, Hydrolase
Abstract: The use of pseudocontact shifts arising from paramagnetic metal ions in a microcrystalline protein sample is proposed as a strategy to obtain unambiguous signal assignments in solid-state NMR spectra enabling distance extraction for protein structure calculation. With this strategy, 777 unambiguous (281 sequential, 217 medium-range, and 279 long-range) distance restraints could be obtained from PDSD, DARR, CHHC, and the recently introduced PAR and PAIN-CP solid-state experiments for the cobalt(II)-substituted catalytic domain of matrix metalloproteinase 12 (159 amino acids, 17.6 kDa). The obtained structure is a high resolution one, with backbone rmsd of 1.0 +/- 0.2 A, and is in good agreement with the X-ray structure (rmsd to X-ray 1.3 A). The proposed strategy, which may be generalized for nonmetalloproteins with the use of paramagnetic tags, represents a significant step ahead in protein structure determination using solid-state NMR.
Published: 2009
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40. Solid-State NMR and DFT Combined for the Surface Study of Functionalized Silicon Nanoparticles

Author: Myriam Chanal, Monu Kaushik, Lionel Dubois, Névine Rochat, Gaël De Paëpe, Florence Duclairoir, Hanako Okuno, Daniel Lee, Michel Bardet, Romain Coustel, Yves Chenavier, Jean-Marie Mouesca, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Reconnaissance Ionique et Chimie de Coordination (RICC), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-08-CEXC-0003,DNP4NanoCarac,Polarisation Dynamique Nucléaire : amélioration de la sensibilité en RMN solide haute résolution pour l'étude structurale 3D de nanotubes fonctionnalisés et autres nano-objets(2008), ANR-12-BS08-0016,CryoMAS4DNP,Polarisation dynamique nucléaire en rotation à l'angle magique à très basse température et à haut champ magnétique(2012), European Project: 237646,EC:FP7:PEOPLE,FP7-PEOPLE-IEF-2008,DNP4NANOCARAC(2009), European Project: 228664,EC:FP7:PEOPLE,FP7-PEOPLE-2007-2-3-COFUND,EUROTALENTS(2009), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Université Grenoble Alpes (UGA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Service de Physique des Matériaux et Microstructures (SP2M - UMR 9002), Université Grenoble Alpes (UGA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Grenoble Alpes (UGA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Magnetic Resonance [?-2019] (RM [?-2019]), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Laboratoire d'Etude des Matériaux par Microscopie Avancée [?-2019] (LEMMA [?-2019]), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: inorganic chemicals, Silicon, Hydrosilylation, Nanoparticle, chemistry.chemical_element, Nanotechnology, Photochemistry, Catalysis, chemistry.chemical_compound, NMR spectroscopy, Molecule, [CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS, health care economics and organizations, density functional theory, Chemistry, Chemical shift, Organic Chemistry, technology, industry, and agriculture, hydrosilylation, silicon, General Chemistry, Nuclear magnetic resonance spectroscopy, [CHIM.MATE]Chemical Sciences/Material chemistry, Solid-state nuclear magnetic resonance, 13. Climate action, Density functional theory, nanoparticles
Abstract: International audience; Silicon nanoparticles (NPs) serve a wide range of optical, electronic, and biological applications. Chemical grafting of various molecules to Si NPs can help to passivate their reactive surfaces, fine-tune their properties, or even give them further interesting features. In this work, H-1, C-13, and Si-29 solid-state NMR spectroscopy has been combined with density functional theory calculations to study the surface chemistry of hydride-terminated and alkyl-functionalized Si NPs. This combination of techniques yields assignments for the observed chemical shifts, including the contributions resulting from different surface planes, and highlights the presence of physisorbed water. Resonances from near-surface C-13 nuclei were shown to be substantially broadened due to surface disorder and it is demonstrated that in an ambient environment hydride-terminated Si NPs undergo fast back-bond oxidation, whereas long-chain alkyl-functionalized Si NPs undergo slow oxidation. Furthermore, the combination of NMR spectroscopy and DFT calculations showed that the employed hydrosilylation reaction involves anti-Markovnikov addition of the 1-alkene to the surface of the Si NPs.
Published: 2015
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41. Nuclear depolarization and absolute sensitivity in magic-angle spinning cross effect dynamic nuclear polarization

Author: Daniel Lee, Akiva Feintuch, Sabine Hediger, Subhradip Paul, Gaël De Paëpe, Frederic Mentink-Vigier, Shimon Vega, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Weizmann Institute of Science [Rehovot, Israël], ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-12-BS08-0016,CryoMAS4DNP,Polarisation dynamique nucléaire en rotation à l'angle magique à très basse température et à haut champ magnétique(2012), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: [PHYS]Physics [physics], Nitroxide mediated radical polymerization, C-13-C-13 Correlation Spectroscopy, Enhanced NMR, Chemistry, General Physics and Astronomy, Depolarization, Observable, Polarization (waves), Solid-state NMR, Rotating Solids, Nuclear magnetic resonance, Solid-state nuclear magnetic resonance, Magic angle spinning, Physical and Theoretical Chemistry, Atomic physics, C-13 NMR, Spinning, Microwave
Abstract: International audience; Over the last two decades solid state Nuclear Magnetic Resonance has witnessed a breakthrough in increasing the nuclear polarization, and thus experimental sensitivity, with the advent of Magic Angle Spinning Dynamic Nuclear Polarization (MAS-DNP). To enhance the nuclear polarization of protons, exogenous nitroxide biradicals such as TOTAPOL or AMUPOL are routinely used. Their efficiency is usually assessed as the ratio between the NMR signal intensity in the presence and the absence of microwave irradiation epsilon(on/off). While TOTAPOL delivers an enhancement epsilon(on/off) of about 60 on a model sample, the more recent AMUPOL is more efficient: >200 at 100 K. Such a comparison is valid as long as the signal measured in the absence of microwaves is merely the Boltzmann polarization and is not affected by the spinning of the sample. However, recent MAS-DNP studies at 25 K by Thurber and Tycko (2014) have demonstrated that the presence of nitroxide biradicals combined with sample spinning can lead to a depolarized nuclear state, below the Boltzmann polarization. In this work we demonstrate that TOTAPOL and AMUPOL both lead to observable depolarization at approximate to 110 K, and that the magnitude of this depolarization is radical dependent. Compared to the static sample, TOTAPOL and AMUPOL lead, respectively, to nuclear polarization losses of up to 20% and 60% at a 10 kHz MAS frequency, while Trityl OX63 does not depolarize at all. This experimental work is analyzed using a theoretical model that explains how the depolarization process works under MAS and gives new insights into the DNP mechanism and into the spin parameters, which are relevant for the efficiency of a biradical. In light of these results, the outstanding performance of AMUPOL must be revised and we propose a new method to assess the polarization gain for future radicals.
Published: 2015
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42. Frontispiece: Matrix-Free DNP-Enhanced NMR Spectroscopy of Liposomes Using a Lipid-Anchored Biradical

Author: Daniel Lee, Lionel Dubois, Alexandre Richard, Yves Chenavier, Sabine Hediger, Hiroki Takahashi, Gaël De Paëpe, Carlos Fernández‐de‐Alba, and Vincent Maurel
Subjects: Deuterium NMR, Liposome, Chemistry, Organic Chemistry, General Chemistry, Fluorine-19 NMR, Nuclear magnetic resonance crystallography, Nuclear magnetic resonance spectroscopy, Photochemistry, Catalysis, Matrix (chemical analysis), Membrane, Organic chemistry, Transverse relaxation-optimized spectroscopy
Published: 2015
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43. Matrix-Free DNP-Enhanced NMR Spectroscopy of Liposomes Using a Lipid-Anchored Biradical

Author: Sabine Hediger, Daniel Lee, Gaël De Paëpe, Vincent Maurel, Lionel Dubois, Yves Chenavier, Carlos Fernández‐de‐Alba, Alexandre Richard, Hiroki Takahashi, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Reconnaissance Ionique et Chimie de Coordination (RICC), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-12-BS08-0016,CryoMAS4DNP,Polarisation dynamique nucléaire en rotation à l'angle magique à très basse température et à haut champ magnétique(2012), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Glycerol, Free Radicals, Propanols, Lipid Bilayers, Dynamic Nuclear-Polarization, chemical and pharmacologic phenomena, Fluorine-19 NMR, Photochemistry, C-13-C-13 Correlation, Catalysis, Solid-State NMR Spectroscopy, Cyclic N-Oxides, chemistry.chemical_compound, Abundance, Organic chemistry, Molecule, Lipid bilayer, Nuclear Magnetic Resonance, Biomolecular, Phospholipids, Spectroscopy, Dynamic Nuclear Polarization, [PHYS]Physics [physics], Liposome, Membranes, Chemistry, Dimethyl sulfoxide, Organic Chemistry, technology, industry, and agriculture, Proteins, General Chemistry, Nuclear magnetic resonance spectroscopy, NMR, Membrane, Solid-state nuclear magnetic resonance, Bilayers, Liposomes, Interdigitated Gel Phase, lipids (amino acids, peptides, and proteins), Signal Enhancement, Solid-State NMR
Abstract: International audience; Magic-angle spinning dynamic nuclear polarization (MAS-DNP) has been proven to be a powerful technique to enhance the sensitivity of solid-state NMR (SSNMR) in a wide range of systems. Here, we show that DNP can be used to polarize lipids using a lipid-anchored polarizing agent. More specifically, we introduce a C16-functionalized biradical, which allows localization of the polarizing agents in the lipid bilayer and DNP experiments to be performed in the absence of excess cryo-protectant molecules (glycerol, dimethyl sulfoxide, etc.). This constitutes another original example of the matrix-free DNP approach that we recently introduced.
Published: 2015
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44. A New Tool for NMR Crystallography: Complete C-13/N-15 Assignment of Organic Molecules at Natural Isotopic Abundance Using DNP-Enhanced Solid-State NMR

Author: Katharina Märker, Morgane Pingret, Sabine Hediger, Jean-Marie Mouesca, Didier Gasparutto, Gaël De Paëpe, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire Lésions des Acides Nucléiques (LAN), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), ANR-12-BS08-0016,CryoMAS4DNP,Polarisation dynamique nucléaire en rotation à l'angle magique à très basse température et à haut champ magnétique(2012), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: [PHYS]Physics [physics], 010405 organic chemistry, Chemistry, Chemical shift, Resolution (electron density), Crystal-Structure Prediction, Natural abundance, General Chemistry, Fluorine-19 NMR, Nuclear magnetic resonance crystallography, Guanosine Derivatives, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, 0104 chemical sciences, Crystallography, Colloid and Surface Chemistry, Solid-state nuclear magnetic resonance, Dynamic nuclear-polarization, Molecule, C-13-C-13 correlation spectroscopy, Phosphorus-31 NMR spectroscopy
Abstract: International audience; NMR crystallography of organic molecules at natural isotopic abundance (NA) strongly relies on the comparison of assigned experimental and computed NMR chemical shifts. However, a broad applicability of this approach is often hampered by the still limited H-1 resolution and/or difficulties in assigning C-13 and N-15 resonances without the use of structure-based chemical shift calculations. As shown here, such difficulties can be overcome by C-13-C-13 and for the first time N-15-C-13 correlation experiments, recorded with the help of dynamic nuclear polarization. We present the complete de novo C-13 and N-15 resonance assignment at NA of a self-assembled 2'-deoxyguanosine derivative presenting two different molecules in the asymmetric crystallographic unit cell. This de novo assignment method is exclusively based on aforementioned correlation spectra and is an important addition to the NMR crystallography approach, rendering firstly H-1 assignment straightforward, and being secondly a prerequisite for distance measurements with solid-state NMR.
Published: 2015
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45. Is solid-state NMR enhanced by dynamic nuclear polarization?

Author: Sabine Hediger, Daniel Lee, Gaël De Paëpe, Magnetic Resonance (RM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-08-CEXC-0003,DNP4NanoCarac,Polarisation Dynamique Nucléaire : amélioration de la sensibilité en RMN solide haute résolution pour l'étude structurale 3D de nanotubes fonctionnalisés et autres nano-objets(2008), ANR-12-BS08-0016,CryoMAS4DNP,Polarisation dynamique nucléaire en rotation à l'angle magique à très basse température et à haut champ magnétique(2012), European Project: 228664,EC:FP7:PEOPLE,FP7-PEOPLE-2007-2-3-COFUND,EUROTALENTS(2009), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Nuclear and High Energy Physics, C-13-C-13 Correlation Spectroscopy, Analytical chemistry, Natural abundance, 010402 general chemistry, 01 natural sciences, Molecular physics, Solid-state NMR, Dynamic nuclear polarization, Cross-Polarization, Magic angle spinning, MAS-NMR, Hyperpolarization (physics), Spectral resolution, Spectroscopy, Instrumentation, Metal-Organic Frameworks, [PHYS]Physics [physics], Radiation, Zeolite, 010405 organic chemistry, Chemistry, General Chemistry, Polarization (waves), Polarizing Agents, 0104 chemical sciences, Amorphous solid, Solid-state nuclear magnetic resonance, Sn-Beta
Abstract: International audience; The recent trend of high-held (similar to 5-20 T), low-temperature (similar to 100 K) ssNMR combined with dynamic nuclear polarization (DNP) under magic angle spinning (MAS) conditions is analyzed. A brief overview of the current theory of hyperpolarization for so-called MAS-DNP experiments is given, along with various reasons why the DNP-enhancement, the ratio of the NMR signal intensities obtained in the presence and absence of microwave irradiation suitable for hyperpolarization, should not be used alone to gauge the value of performing MAS-DNP experiments relative to conventional ssNMR. This is demonstrated through a dissection of the current conditions required for MAS-DNP with particular attention to resulting absolute sensitivities and spectral resolution. Consequently, sample preparation methods specifically avoiding the surplus of glass-forming solvents so as to improve the absolute sensitivity and resolution are discussed, as are samples that are intrinsically pertinent for MAS-DNP studies (high surface area, amorphous, and porous). Owing to their pertinence, examples of recent applications on these types of samples where chemically-relevant information has been obtained that would have been impossible without the sensitivity increases bestowed by MAS-DNP are also detailed. Additionally, a promising further implementation for MAS-DNP is exampled, whereby the sensitivity improvements shown for (correlation) spectroscopy of nuclei at low natural isotopic abundance, facilitate internuclear distance measurements, especially for long distances (absence of dipolar truncation). Finally, we give some speculative perspectives for MAS-DNP. (C) 2015 Elsevier Inc. All rights reserved.
Published: 2015
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46. Third Spin-Assisted Recoupling in SSNMR

Author: Subhradip Paul, Hiroki Takahashi, Sabine Hediger, and Gaël De Paëpe
Subjects: Dipole, Magnetization, Nuclear magnetic resonance, Spins, Solid-state nuclear magnetic resonance, Chemistry, Quantum mechanics, Magic angle spinning, Biomolecular structure, Magnetic dipole–dipole interaction, Spin-½
Abstract: In solid-state nuclear magnetic resonance (SSNMR) under magic-angle spinning (MAS), the dipolar interactions (that contains distance information), averaged out by sample spinning, can be reintroduced by the application of carefully designed radiofrequency pulses called dipolar recoupling sequences. In this review, we will essentially focus on a recently introduced recoupling mechanism namely third spin-assisted recoupling (TSAR) which allows exchanging magnetization between two spins (say A and B) without relying on the reintroduction of the AB dipolar coupling. Instead, it uses a second-order effect driven by a cross-term between two dipolar terms (AH and BH) where H stands for an assisting spin (typically a proton). After a theory section delineating the principles of TSAR and of its related sequences (PAR and PAIN-CP), we will discuss some practical aspects of its experimental implementation (at moderate and ultra-high spinning frequencies) and its ability to provide structurally relevant C–C, N–C, and N–N distance information. Finally, recent applications of TSAR for structure determination of biomolecules will be overviewed.
Published: 2015
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47. Characterization of heteronuclear decoupling through proton spin dynamics in solid-state nuclear magnetic resonance spectroscopy

Author: Bénédicte Elena, Gaël De Paëpe, Lyndon Emsley, Laboratoire de Chimie - UMR5182 (LC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Chemistry, General Physics and Astronomy, 02 engineering and technology, Decoupling (cosmology), 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Molecular physics, Homonuclear molecule, 0104 chemical sciences, Nuclear physics, Heteronuclear molecule, Proton spin crisis, Spin echo, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, 0210 nano-technology, Phase modulation, ComputingMilieux_MISCELLANEOUS, Magnetic dipole–dipole interaction, Nuclear magnetic resonance decoupling
Abstract: The work presented here aims at understanding the performance of phase modulated heteronuclear decoupling sequences such as Cosine Modulation or Two Pulse Phase Modulation. To that end we provide an analytical description of the intrinsic behavior of Cosine Modulation decoupling with respect to radio-frequency-inhomogeneity and the proton-proton dipolar coupling network. We discover through a Modulation Frame average Hamiltonian analysis that best decoupling is obtained under conditions where the heteronuclear interactions are removed but notably where homonuclear couplings are recoupled at a homonuclear Rotary Resonance (HORROR) condition in the Modulation Frame. These conclusions are supported by extensive experimental investigations, and notably through the introduction of proton nutation experiments to characterize spin dynamics in solids under decoupling conditions. The theoretical framework presented in this paper allows the prediction of the optimum parameters for a given set of experimental conditions. (C) 2004 American Institute of Physics.
Published: 2004
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48. Improved heteronuclear decoupling schemes for solid-state magic angle spinning NMR by direct spectral optimization

Author: Lyndon Emsley, Paul Hodgkinson, and Gaël De Paëpe
Subjects: NMR spectra database, Dipole, Magic angle, Heteronuclear molecule, Chemistry, Magic angle spinning, Analytical chemistry, General Physics and Astronomy, Pulse sequence, Decoupling (cosmology), Physical and Theoretical Chemistry, Spinning, Computational physics
Abstract: It is shown that a direct spectral optimization scheme can be implemented to obtain improved heteronuclear dipolar decoupling schemes for solid-state magic-angle-spinning NMR experiments. The resulting schemes, which turn out to have a particularly simple form, are shown to be applicable over the whole range of commercially available spinning speeds (from 5 to 35 kHz), and are shown to improve on the performance of the best existing sequences. (C) 2003 Elsevier Science B.V. All rights reserved.
Published: 2003
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49. Heteronuclear decoupling in NMR of Liquid Crystals using continuous phase modulation

Author: Paul Hodgkinson, Lyndon Emsley, Dimitris Sakellariou, Gaël De Paëpe, and Sabine Hediger
Subjects: Condensed Matter::Quantum Gases, Continuous phase modulation, Chemistry, Analytical chemistry, Phase (waves), General Physics and Astronomy, Pulse sequence, Molecular physics, NMR spectra database, Heteronuclear molecule, Liquid crystal, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, Physical and Theoretical Chemistry, Decoupling (electronics), Heteronuclear single quantum coherence spectroscopy
Abstract: In this Letter we present a framework for the use of continuously phase modulated radio-frequency pulses for heteronuclear decoupling in NMR of Liquid Crystals. Within this framework, we found new sets of heteronuclear decoupling sequences using numerical optimisation. These sequences and supercycles are tested experimentally on a model liquid crystal, and their performance is compared with standard heteronuclear decoupling sequences. (C) 2002 Elsevier Science B.V. All rights reserved.
Published: 2003
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50. Ultra-Low Temperature Nuclear Magnetic Resonance

Author: Eric Bouleau, Sabine Hediger, Pierre Saint-Bonnet, Gaël De Paëpe, and Daniel Lee
Subjects: Free induction decay, Cryostat, Nuclear magnetic resonance, Materials science, Solid-state nuclear magnetic resonance, Spin echo, Nuclear magnetic resonance spectroscopy, Atmospheric temperature range, Ferromagnetic resonance, Nuclear magnetic resonance decoupling
Abstract: Because NMR spectroscopy requests more sensitivity and more resolution, high-frequency and high-power microwave irradiation of electron spins in a magnetic field, Dynamic Nuclear Polarization (DNP) is becoming a common partner for fast sample spinning NMR experiments. Currently, this technics is performed at minimum sample temperatures ~100 K, using cold nitrogen gas to pneumatically spin and cool the sample. The desire is to improve NMR by providing ultra-low temperatures, using cryogenic helium gas. It is shown that stable and fast spinning can be attained for sample temperatures down to 30 K using a cryostat developed in our laboratory. Using this cryostat to cool a closed-loop of helium gas results in spinning frequencies that can greatly surpass those achievable with nitrogen gas. It results in substantial sensitivity enhancements (~ 600) and according experimental time-savings by 2 to 4 orders of magnitude. Therefore, access to this temperature range is demonstrated to be both viable and highly pertinent.
Published: 2017
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