1
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Budny-Godlewski K, Piekarski DG, Justyniak I, Leszczyński MK, Nawrocki J, Kubas A, Lewiński J. Uncovering Factors Controlling Reactivity of Metal-TEMPO Reaction Systems in the Solid State and Solution. Chemistry 2024:e202401968. [PMID: 38801170 DOI: 10.1002/chem.202401968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Accepted: 05/22/2024] [Indexed: 05/29/2024]
Abstract
Nitroxides find application in various areas of chemistry, and a more in-depth understanding of factors controlling their reactivity with metal complexes is warranted to promote further developments. Here, we report on the effect of the metal centre Lewis acidity on both the distribution of the O- and N-centered spin density in 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) and turning TEMPO from the O- to N-radical mode scavenger in metal-TEMPO systems. We use Et(Cl)Zn/TEMPO model reaction system with tuneable reactivity in the solid state and solution. Among various products, a unique Lewis acid-base adduct of Cl2Zn with the N-ethylated TEMPO was isolated and structurally characterised, and the so-called solid-state 'slow chemistry' reaction led to a higher yield of the N-alkylated product. The revealed structure-activity/selectivity correlations are exceptional yet are entirely rationalised by the mechanistic underpinning supported by theoretical calculations of studied model systems. This work lays a foundation and mechanistic blueprint for future metal/nitroxide systems exploration.
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Affiliation(s)
- Krzysztof Budny-Godlewski
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
| | - Dariusz G Piekarski
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Iwona Justyniak
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Michał K Leszczyński
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
| | - Jan Nawrocki
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Adam Kubas
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Janusz Lewiński
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
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2
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Menzildjian G, Schlagnitweit J, Casano G, Ouari O, Gajan D, Lesage A. Polarizing agents for efficient high field DNP solid-state NMR spectroscopy under magic-angle spinning: from design principles to formulation strategies. Chem Sci 2023; 14:6120-6148. [PMID: 37325158 PMCID: PMC10266460 DOI: 10.1039/d3sc01079a] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/09/2023] [Indexed: 06/17/2023] Open
Abstract
Dynamic Nuclear Polarization (DNP) has recently emerged as a cornerstone approach to enhance the sensitivity of solid-state NMR spectroscopy under Magic Angle Spinning (MAS), opening unprecedented analytical opportunities in chemistry and biology. DNP relies on a polarization transfer from unpaired electrons (present in endogenous or exogenous polarizing agents) to nearby nuclei. Developing and designing new polarizing sources for DNP solid-state NMR spectroscopy is currently an extremely active research field per se, that has recently led to significant breakthroughs and key achievements, in particular at high magnetic fields. This review describes recent developments in this area, highlighting key design principles that have been established over time and led to the introduction of increasingly more efficient polarizing sources. After a short introduction, Section 2 presents a brief history of solid-state DNP, highlighting the main polarization transfer schemes. The third section is devoted to the development of dinitroxide radicals, discussing the guidelines that were progressively established to design the fine-tuned molecular structures in use today. In Section 4, we describe recent efforts in developing hybrid radicals composed of a narrow EPR line radical covalently linked to a nitroxide, highlighting the parameters that modulate the DNP efficiency of these mixed structures. Section 5 reviews recent advances in the design of metal complexes suitable for DNP MAS NMR as exogenous electron sources. In parallel, current strategies that exploit metal ions as endogenous polarization sources are discussed. Section 6 briefly describes the recent introduction of mixed-valence radicals. In the last part, experimental aspects regarding sample formulation are reviewed to make best use of these polarizing agents in a broad panel of application fields.
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Affiliation(s)
- Georges Menzildjian
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
| | - Judith Schlagnitweit
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
| | - Gilles Casano
- Aix Marseille Univ., CNRS, Institut de Chimie Radicalaire, UMR 7273 Marseille France
| | - Olivier Ouari
- Aix Marseille Univ., CNRS, Institut de Chimie Radicalaire, UMR 7273 Marseille France
| | - David Gajan
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
| | - Anne Lesage
- Centre de RMN à, Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) 5 Rue de la doua 69100 Villeurbanne France
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3
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Rao Y, Palumbo CT, Venkatesh A, Keener M, Stevanato G, Chauvin AS, Menzildjian G, Kuzin S, Yulikov M, Jeschke G, Lesage A, Mazzanti M, Emsley L. Design Principles for the Development of Gd(III) Polarizing Agents for Magic Angle Spinning Dynamic Nuclear Polarization. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:11310-11317. [PMID: 35865791 PMCID: PMC9289950 DOI: 10.1021/acs.jpcc.2c01721] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Nuclear magnetic resonance suffers from an intrinsically low sensitivity, which can be overcome by dynamic nuclear polarization (DNP). Gd(III) complexes are attractive exogenous polarizing agents for magic angle spinning (MAS) DNP due to their high chemical stability in contrast to nitroxide-based radicals. However, even the state-of-the-art Gd(III) complexes have so far provided relatively low DNP signal enhancements of ca. 36 in comparison to standard DNP biradicals, which show enhancements of over 200. Here, we report a series of new Gd(III) complexes for DNP and show that the observed DNP enhancements of the new and existing Gd(III) complexes are inversely proportional to the square of the zero-field splitting (ZFS) parameter D, which is in turn determined by the ligand-type and the local coordination environment. The experimental DNP enhancements at 9.4 T and the ZFS parameters measured with pulsed electron paramagnetic resonance (EPR) spectroscopy agree with the above model, paving the way for the development of more efficient Gd(III) polarizing agents.
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Affiliation(s)
- Yu Rao
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Chad T. Palumbo
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Amrit Venkatesh
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Megan Keener
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Gabriele Stevanato
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Anne-Sophie Chauvin
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Georges Menzildjian
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sergei Kuzin
- Laboratory
of Physical Chemistry, Department of Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Maxim Yulikov
- Laboratory
of Physical Chemistry, Department of Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Gunnar Jeschke
- Laboratory
of Physical Chemistry, Department of Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Anne Lesage
- Centre
de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Marinella Mazzanti
- Group
of Coordination Chemistry, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL, CH-1015 Lausanne, Switzerland
| | - Lyndon Emsley
- Laboratory
of Magnetic Resonance, Institut des Sciences et Ingénierie
Chimiques, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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4
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Jabbour R, Renom-Carrasco M, Chan KW, Völker L, Berruyer P, Wang Z, Widdifield CM, Lelli M, Gajan D, Copéret C, Thieuleux C, Lesage A. Multiple Surface Site Three-Dimensional Structure Determination of a Supported Molecular Catalyst. J Am Chem Soc 2022; 144:10270-10281. [PMID: 35642739 DOI: 10.1021/jacs.2c01013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The structural characterization of supported molecular catalysts is challenging due to the low density of active sites and the presence of several organic/organometallic surface groups resulting from the often complex surface chemistry associated with support functionalization. Here, we provide a complete atomic-scale description of all surface sites in an N-heterocyclic carbene based on iridium and supported on silica, at all stages of its synthesis. By combining a suitable isotope labeling strategy with the implementation of multinuclear dipolar recoupling DNP-enhanced NMR experiments, the 3D structure of the Ir-NHC sites, as well as that of the synthesis intermediates were determined. As a significant fraction of parent surface fragments does not react during the multistep synthesis, site-selective experiments were implemented to specifically probe proximities between the organometallic groups and the solid support. The NMR-derived structure of the iridium sites points to a well-defined conformation. By interpreting EXAFS spectroscopy and chemical analysis data augmented by computational studies, the presence of two coordination geometries is demonstrated: Ir-NHC fragments coordinated by a 1,5-cyclooctadiene and one Cl ligand, as well as, more surprisingly, a fragment coordinated by two NHC and two Cl ligands. This study demonstrates a unique methodology to disclose individual surface structures in complex, multisite environments, a long-standing challenge in the field of heterogeneous/supported catalysts, while revealing new, unexpected structural features of metallo-NHC-supported substrates. It also highlights the potentially large diversity of surface sites present in functional materials prepared by surface chemistry, an essential knowledge to design materials with improved performances.
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Affiliation(s)
- Ribal Jabbour
- Université de Lyon, CNRS, ENS Lyon, Université Lyon 1, Centre de RMN de Lyon, UMR 5082, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Marc Renom-Carrasco
- Université de Lyon, Institut de Chimie de Lyon, CP2M, UMR 5128 CNRS-CPE Lyon-UCBL, CPE Lyon, 43 Bvd du 11 Novembre 1918, 69100 Villeurbanne, France
| | - Ka Wing Chan
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Laura Völker
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Pierrick Berruyer
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Zhuoran Wang
- Université de Lyon, CNRS, ENS Lyon, Université Lyon 1, Centre de RMN de Lyon, UMR 5082, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Cory M Widdifield
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - Moreno Lelli
- Magnetic Resonance Center (CERM), University of Florence, 50019 Sesto Fiorentino, FI, Italy
| | - David Gajan
- Université de Lyon, CNRS, ENS Lyon, Université Lyon 1, Centre de RMN de Lyon, UMR 5082, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Chloé Thieuleux
- Université de Lyon, Institut de Chimie de Lyon, CP2M, UMR 5128 CNRS-CPE Lyon-UCBL, CPE Lyon, 43 Bvd du 11 Novembre 1918, 69100 Villeurbanne, France
| | - Anne Lesage
- Université de Lyon, CNRS, ENS Lyon, Université Lyon 1, Centre de RMN de Lyon, UMR 5082, 5 rue de la Doua, 69100 Villeurbanne, France
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5
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Carnahan SL, Chen Y, Wishart JF, Lubach JW, Rossini AJ. Magic angle spinning dynamic nuclear polarization solid-state NMR spectroscopy of γ-irradiated molecular organic solids. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2022; 119:101785. [PMID: 35405629 DOI: 10.1016/j.ssnmr.2022.101785] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 02/22/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
In the past 15 years, magic angle spinning (MAS) dynamic nuclear polarization (DNP) has emerged as a method to increase the sensitivity of high-resolution solid-state NMR spectroscopy experiments. Recently, γ-irradiation has been used to generate significant concentrations of homogeneously distributed free radicals in a variety of solids, including quartz, glucose, and cellulose. Both γ-irradiated quartz and glucose previously showed significant MAS DNP enhancements. Here, γ-irradiation is applied to twelve small organic molecules to test the applicability of γ-irradiation as a general method of creating stable free radicals for MAS DNP experiments on organic solids and pharmaceuticals. Radical concentrations in the range of 0.25 mM-10 mM were observed in irradiated glucose, histidine, malic acid, and malonic acid, and significant 1H DNP enhancements of 32, 130, 19, and 11 were obtained, respectively, as measured by 1H→13C CPMAS experiments. However, concentrations of free radicals below 0.05 mM were generally observed in organic molecules containing aromatic rings, preventing sizeable DNP enhancements. DNP sensitivity gains for several of the irradiated compounds exceed that which can be obtained with the relayed DNP approach that uses exogeneous polarizing agent solutions and impregnation procedures. In several cases, significant 1H DNP enhancements were realized at room temperature. This study demonstrates that in many cases γ-irradiation is a viable alternative to addition of stable exogenous radicals for DNP experiments on organic solids.
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Affiliation(s)
- Scott L Carnahan
- US DOE Ames Laboratory, Ames, IA, 50011, USA; Iowa State University, Department of Chemistry, Ames, IA, 50011, USA
| | - Yunhua Chen
- US DOE Ames Laboratory, Ames, IA, 50011, USA; Iowa State University, Department of Chemistry, Ames, IA, 50011, USA
| | - James F Wishart
- Brookhaven National Laboratory, Chemistry Division, Upton, NY, 11973, United States
| | - Joseph W Lubach
- Genentech Inc., South San Francisco, CA, 94080, United States
| | - Aaron J Rossini
- US DOE Ames Laboratory, Ames, IA, 50011, USA; Iowa State University, Department of Chemistry, Ames, IA, 50011, USA.
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6
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Perras FA, Kanbur U, Paterson AL, Chatterjee P, Slowing II, Sadow AD. Determining the Three-Dimensional Structures of Silica-Supported Metal Complexes from the Ground Up. Inorg Chem 2021; 61:1067-1078. [PMID: 34962783 DOI: 10.1021/acs.inorgchem.1c03200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The immobilization of molecularly precise metal complexes to substrates, such as silica, provides an attractive platform for the design of active sites in heterogeneous catalysts. Specific steric and electronic variations of the ligand environment enable the development of structure-activity relationships and the knowledge-driven design of catalysts. At present, however, the three-dimensional environment of the precatalyst, much less the active site, is generally not known for heterogeneous single-site catalysts. We explored the degree to which NMR-based surface-to-complex interatomic distances could be used to solve the three-dimensional structures of three silica-supported metal complexes. The structure solution revealed unexpected features related to the environment around the metal that would be difficult to discern otherwise. This approach appears to be highly robust and, due to its simplicity, is readily applied to most single-site catalysts with little extra effort.
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Affiliation(s)
| | - Uddhav Kanbur
- US DOE, Ames Laboratory, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | | | - Puranjan Chatterjee
- US DOE, Ames Laboratory, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Igor I Slowing
- US DOE, Ames Laboratory, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Aaron D Sadow
- US DOE, Ames Laboratory, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
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7
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Wang F, Ramakrishna SK, Sun P, Fu R. Triple-pulse excitation: An efficient way for suppressing background signals and eliminating radio-frequency acoustic ringing in direct polarization NMR experiments. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 332:107067. [PMID: 34634650 DOI: 10.1016/j.jmr.2021.107067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/06/2021] [Accepted: 09/11/2021] [Indexed: 06/13/2023]
Abstract
Direct polarization using a single pulse is the simplest excitation scheme in nuclear magnetic resonance (NMR) experiments, capable of quantifying various compositions in many materials applications. However, this single-pulse excitation generally gives rise to NMR spectra with a severely distorted baseline due to the background signals arising from probe components and/or due to the radio-frequency (RF) acoustic ringing, especially in low-γ nuclei and wide-line NMR. In this work, a triple-pulse excitation scheme is proposed to simultaneously suppress the background signals and eliminate the RF acoustic ringing. The acoustic ringing is cancelled through subtraction in any two consecutive scans by alternating the receiver phase while keeping the phase of the pulse right before acquisition the same. While the triple-pulse scheme generates an additional flip-angle dependent scaling to the traditional single-pulse excitation profile in such a way that the scaling is one when the flip-angle is ∼90° but becomes almost zero when the flip-angle is very small. Therefore, the background signals arising from the materials outside the sample coil experiencing a very small fraction of the RF flip-angles can be effectively suppressed. Various samples containing 1H and quadrupolar nuclei (17O, 25Mg, and 23Na) have been used to demonstrate the effectiveness of this newly proposed triple-pulse excitation in terms of suppressing the background signals and eliminating the acoustic ringing effects.
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Affiliation(s)
- Fenfen Wang
- Key Laboratory of Functional Polymer Materials of the Ministry of Education and College of Chemistry, State Key Laboratory of Medicinal Chemical Biology, Nankai University and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300071, China
| | - Sanath K Ramakrishna
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA; National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310, USA
| | - Pingchuan Sun
- Key Laboratory of Functional Polymer Materials of the Ministry of Education and College of Chemistry, State Key Laboratory of Medicinal Chemical Biology, Nankai University and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300071, China
| | - Riqiang Fu
- National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310, USA.
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8
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Nevzorov AA, Marek A, Milikisiyants S, Smirnov AI. Characterization of photonic band resonators for DNP NMR of thin film samples at 7 T magnetic field. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 323:106893. [PMID: 33418455 PMCID: PMC8362290 DOI: 10.1016/j.jmr.2020.106893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
Polarization of nuclear spins via Dynamic Nuclear Polarization (DNP) relies on generating sufficiently high mm-wave B1e fields over the sample, which could be achieved by developing suitable resonance structures. Recently, we have introduced one-dimensional photonic band gap (1D PBG) resonators for DNP and reported on prototype devices operating at ca. 200 GHz electron resonance frequency. Here we systematically compare the performance of five (5) PBG resonators constructed from various alternating dielectric layers by monitoring the DNP effect on natural-abundance 13C spins in synthetic diamond microparticles embedded into a commercial polyester-based lapping film of just 3 mil (76 μm) thickness. An odd-numbered configuration of dielectric layers for 1D PBG resonator was introduced to achieve further B1e enhancements. Among the PBG configurations tested, combinations of high-ε perovskite LiTaO3 together with AlN as well as AlN with optical quartz wafers have resulted in ca. 40 to over 50- fold gains in the average mm-wave power over the sample vs. the mirror-only configuration. The results are rationalized in terms of the electromagnetic energy distribution inside the resonators obtained analytically and from COMSOL simulations. It was found that average of B1e2 over the sample strongly depends on the arrangement of the dielectric layers that are the closest to the sample, which favors odd-numbered PBG resonator configurations for their use in DNP.
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Affiliation(s)
- Alexander A Nevzorov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
| | - Antonin Marek
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Sergey Milikisiyants
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
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9
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Yakimov AV, Mance D, Searles K, Copéret C. A Formulation Protocol with Pyridine to Enable Dynamic Nuclear Polarization Surface-Enhanced NMR Spectroscopy on Reactive Surface Sites: Case Study with Olefin Polymerization and Metathesis Catalysts. J Phys Chem Lett 2020; 11:3401-3407. [PMID: 32271018 DOI: 10.1021/acs.jpclett.0c00716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Dynamic nuclear polarization surface-enhanced NMR spectroscopy (DNP-SENS) has emerged as a powerful characterization tool in material chemistry and heterogeneous catalysis by dramatically increasing, by up to 2 orders of magnitude, the NMR signals associated with surface sites. DNP-SENS mostly relies on using exogenous polarizing agents (PAs), typically dinitroxyl radicals, to boost the NMR signals. However, the PAs may interact with the surface or even react with surface sites, thus leading to loss or quenching of DNP enhancements. Herein, we describe the development of a DNP-SENS formulation that allows broadening the application of DNP-SENS to samples containing highly reactive surface sites, namely a Ziegler-Natta propylene polymerization catalyst, a sulfated zirconia-supported metallocene, and a silica-supported cationic Mo alkylidene. The protocol consists of adsorbing pyridine prior to the DNP formulation (TEKPol/TCE). The addition of pyridine not only preserves the PAs and thereby restores the DNP enhancement but also allows probing Lewis/Brønsted acid surface sites that are often present on these catalysts.
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Affiliation(s)
| | - Deni Mance
- ETH Zurich, Vladimir-Prelog Weg 1-5/10, 8093 Zurich, Switzerland
| | - Keith Searles
- ETH Zurich, Vladimir-Prelog Weg 1-5/10, 8093 Zurich, Switzerland
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10
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Rodriguez-Gomez A, Chowdhury AD, Caglayan M, Bau JA, Abou-Hamad E, Gascon J. Non-oxidative dehydrogenation of isobutane over supported vanadium oxide: nature of the active sites and coke formation. Catal Sci Technol 2020. [DOI: 10.1039/d0cy01174f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We combine Raman spectroscopy, EPR, XPS, temperature programmed reduction, XRD, 51V MAS ssNMR, TEM and N2-physisorption to unravel structure–activity relationships during the non-oxidative dehydrogenation of isobutane over a V based catalyst.
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Affiliation(s)
- Alberto Rodriguez-Gomez
- KAUST Catalysis Center (KCC)
- Advanced Catalytic Materials
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
| | - Abhishek Dutta Chowdhury
- KAUST Catalysis Center (KCC)
- Advanced Catalytic Materials
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
| | - Mustafa Caglayan
- KAUST Catalysis Center (KCC)
- Advanced Catalytic Materials
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
| | - Jeremy A. Bau
- KAUST Catalysis Center (KCC)
- Advanced Catalytic Materials
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
| | - Edy Abou-Hamad
- Core Labs
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
| | - Jorge Gascon
- KAUST Catalysis Center (KCC)
- Advanced Catalytic Materials
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
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11
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Dutta Chowdhury A, Yarulina I, Abou-Hamad E, Gurinov A, Gascon J. Surface enhanced dynamic nuclear polarization solid-state NMR spectroscopy sheds light on Brønsted-Lewis acid synergy during the zeolite catalyzed methanol-to-hydrocarbon process. Chem Sci 2019; 10:8946-8954. [PMID: 32190235 PMCID: PMC7068724 DOI: 10.1039/c9sc02215e] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/20/2019] [Indexed: 02/02/2023] Open
Abstract
After a prolonged effort over two decades, the reaction mechanism of the zeolite-catalyzed methanol-to-hydrocarbon (MTH) process is now well-understood: the so-called 'direct mechanism' (via direct coupling of two methanol molecules) is responsible for the formation of the initial carbon-carbon bonds, while the hydrocarbon pool (HCP)-based dual cycle mechanism is responsible for the formation of reaction products. While most of the reaction events occur at zeolite Brønsted acid sites, the addition of Lewis acid sites (i.e., via the introduction of alkaline earth cations like calcium) has been shown to inhibit the formation of deactivating coke species and hence increase the catalyst lifetime. With the aim to have an in-depth mechanistic understanding, herein, we employ magic angle spinning surface-enhanced dynamic nuclear polarization solid-state NMR spectroscopy to illustrate that the inclusion of Lewis acidity prevents the formation of carbene/ylide species on the zeolite, directly affecting the equilibrium between arene and olefin cycles of the HCP mechanism and hence regulating the ultimate product selectivity and catalyst lifetime.
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Affiliation(s)
- Abhishek Dutta Chowdhury
- King Abdullah University of Science and Technology , KAUST Catalysis Center , Advanced Catalytic Materials , Thuwal 23955 , Saudi Arabia . ;
| | - Irina Yarulina
- King Abdullah University of Science and Technology , KAUST Catalysis Center , Advanced Catalytic Materials , Thuwal 23955 , Saudi Arabia . ;
| | - Edy Abou-Hamad
- King Abdullah University of Science and Technology , KAUST Core Labs , Thuwal 23955 , Saudi Arabia .
| | - Andrei Gurinov
- King Abdullah University of Science and Technology , KAUST Core Labs , Thuwal 23955 , Saudi Arabia .
| | - Jorge Gascon
- King Abdullah University of Science and Technology , KAUST Catalysis Center , Advanced Catalytic Materials , Thuwal 23955 , Saudi Arabia . ;
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12
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Samantaray MK, D'Elia V, Pump E, Falivene L, Harb M, Ould Chikh S, Cavallo L, Basset JM. The Comparison between Single Atom Catalysis and Surface Organometallic Catalysis. Chem Rev 2019; 120:734-813. [PMID: 31613601 DOI: 10.1021/acs.chemrev.9b00238] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Single atom catalysis (SAC) is a recent discipline of heterogeneous catalysis for which a single atom on a surface is able to carry out various catalytic reactions. A kind of revolution in heterogeneous catalysis by metals for which it was assumed that specific sites or defects of a nanoparticle were necessary to activate substrates in catalytic reactions. In another extreme of the spectrum, surface organometallic chemistry (SOMC), and, by extension, surface organometallic catalysis (SOMCat), have demonstrated that single atoms on a surface, but this time with specific ligands, could lead to a more predictive approach in heterogeneous catalysis. The predictive character of SOMCat was just the result of intuitive mechanisms derived from the elementary steps of molecular chemistry. This review article will compare the aspects of single atom catalysis and surface organometallic catalysis by considering several specific catalytic reactions, some of which exist for both fields, whereas others might see mutual overlap in the future. After a definition of both domains, a detailed approach of the methods, mostly modeling and spectroscopy, will be followed by a detailed analysis of catalytic reactions: hydrogenation, dehydrogenation, hydrogenolysis, oxidative dehydrogenation, alkane and cycloalkane metathesis, methane activation, metathetic oxidation, CO2 activation to cyclic carbonates, imine metathesis, and selective catalytic reduction (SCR) reactions. A prospective resulting from present knowledge is showing the emergence of a new discipline from the overlap between the two areas.
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Affiliation(s)
- Manoja K Samantaray
- King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Valerio D'Elia
- School of Molecular Science and Engineering (MSE) , Vidyasirimedhi Institute of Science and Technology (VISTEC) , Wang Chan, Payupnai , 21210 Rayong , Thailand
| | - Eva Pump
- King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Laura Falivene
- King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Moussab Harb
- King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Samy Ould Chikh
- King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Luigi Cavallo
- King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Jean-Marie Basset
- King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
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13
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Carnahan SL, Venkatesh A, Perras FA, Wishart JF, Rossini AJ. High-Field Magic Angle Spinning Dynamic Nuclear Polarization Using Radicals Created by γ-Irradiation. J Phys Chem Lett 2019; 10:4770-4776. [PMID: 31347850 DOI: 10.1021/acs.jpclett.9b01655] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
High-field magic angle spinning dynamic nuclear polarization (MAS DNP) is often used to enhance the sensitivity of solid-state nuclear magnetic resonance experiments by transferring spin polarization from electron spins to nuclear spins. Here, we demonstrate that γ-irradiation induces the formation of stable radicals in inorganic solids, such as fused quartz and borosilicate glasses, as well as organic solids, such as glucose, cellulose, and a urea/polyethylene polymer. The radicals were then used to polarize 29Si or 1H spins in the core of some of these materials. Significant MAS DNP enhancements (ε) of more than 400 and 30 were obtained for fused quartz and glucose, respectively. For other samples, negligible values of ε were obtained, likely due to low concentrations of radicals or the presence of abundant quadrupolar spins. These results demonstrate that ionizing radiation is a promising alternative method for generating stable radicals that are suitable for high-field MAS DNP experiments.
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Affiliation(s)
- Scott L Carnahan
- U.S. Department of Energy Ames Laboratory, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Amrit Venkatesh
- U.S. Department of Energy Ames Laboratory, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Frédéric A Perras
- U.S. Department of Energy Ames Laboratory, Ames, Iowa 50011, United States
| | - James F Wishart
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Aaron J Rossini
- U.S. Department of Energy Ames Laboratory, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
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14
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Rankin AGM, Trébosc J, Pourpoint F, Amoureux JP, Lafon O. Recent developments in MAS DNP-NMR of materials. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 101:116-143. [PMID: 31189121 DOI: 10.1016/j.ssnmr.2019.05.009] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/21/2019] [Accepted: 05/21/2019] [Indexed: 05/03/2023]
Abstract
Solid-state NMR spectroscopy is a powerful technique for the characterization of the atomic-level structure and dynamics of materials. Nevertheless, the use of this technique is often limited by its lack of sensitivity, which can prevent the observation of surfaces, defects or insensitive isotopes. Dynamic Nuclear Polarization (DNP) has been shown to improve by one to three orders of magnitude the sensitivity of NMR experiments on materials under Magic-Angle Spinning (MAS), at static magnetic field B0 ≥ 5 T, conditions allowing for the acquisition of high-resolution spectra. The field of DNP-NMR spectroscopy of materials has undergone a rapid development in the last ten years, spurred notably by the availability of commercial DNP-NMR systems. We provide here an in-depth overview of MAS DNP-NMR studies of materials at high B0 field. After a historical perspective of DNP of materials, we describe the DNP transfers under MAS, the transport of polarization by spin diffusion and the various contributions to the overall sensitivity of DNP-NMR experiments. We discuss the design of tailored polarizing agents and the sample preparation in the case of materials. We present the DNP-NMR hardware and the influence of key experimental parameters, such as microwave power, magnetic field, temperature and MAS frequency. We give an overview of the isotopes that have been detected by this technique, and the NMR methods that have been combined with DNP. Finally, we show how MAS DNP-NMR has been applied to gain new insights into the structure of organic, hybrid and inorganic materials with applications in fields, such as health, energy, catalysis, optoelectronics etc.
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Affiliation(s)
- Andrew G M Rankin
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France
| | - Julien Trébosc
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France; Univ. Lille, CNRS-FR2638, Fédération Chevreul, F-59000 Lille, France
| | - Frédérique Pourpoint
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France
| | - Jean-Paul Amoureux
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France; Bruker Biospin, 34 rue de l'industrie, F-67166, Wissembourg, France
| | - Olivier Lafon
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181, UCCS, Unité de Catalyse et Chimie du Solide, F-59000, Lille, France; Institut Universitaire de France, 1 rue Descartes, F-75231, Paris, France.
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15
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Kobayashi T, Pruski M. Spatial Distribution of Silica-Bound Catalytic Organic Functional Groups Can Now Be Revealed by Conventional and DNP-Enhanced Solid-State NMR Methods. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02017] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Takeshi Kobayashi
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, United States
| | - Marek Pruski
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
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16
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17
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Zhao EW, Maligal-Ganesh R, Mentink-Vigier F, Zhao TY, Du Y, Pei Y, Huang W, Bowers CR. Atomic-Scale Structure of Mesoporous Silica-Encapsulated Pt and PtSn Nanoparticles Revealed by Dynamic Nuclear Polarization- Enhanced 29Si MAS NMR Spectroscopy. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:7299-7307. [PMID: 31186824 PMCID: PMC6558955 DOI: 10.1021/acs.jpcc.9b01782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Mesoporous silica encapsulated Pt (Pt@mSiO2) and PtSn (PtSn@mSiO2) nanoparticles (NPs) are representatives of a novel class of heterogeneous catalysts with uniform particle size, enhanced catalytic properties, and superior thermal stability. In the ship-in-a-bottle synthesis, PtSn@mSiO2 intermetallic NPs are derived from Pt@mSiO2 seeds where the mSiO2 shell is formed by polymerization of tetraethyl orthosilicate around a tetradecyltrimethylammonium bromide template, a surfactant used to template MCM-41. Incorporation of Sn into the Pt@mSiO2 seeds is accommodated by chemical etching of the mSiO2 shell. The effect of this etching on the atomic-scale structure of the mSiO2 has not been previously examined, nor has the extent of the structural similarity to MCM-41. Here, the quaternary Q2, Q3 and Q4 sites corresponding to formulas Si(O1/2)2(OH)2, Si(O1/2)3(OH)1 and Si(O1/2)4, in MCM-41 and the mesoporous silica of Pt@mSiO2 and PtSn@mSiO2 NPs were identified and quantified by conventional and dynamic nuclear polarization enhanced Si-29 Magic Angle Spinning Nuclear Magnetic Resonance (DNP MAS NMR). The connectivity of the -Si-O-Si-network was revealed by DNP enhanced two-dimensional 29Si-29Si correlation spectroscopy.
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Affiliation(s)
- Evan Wenbo Zhao
- Department of Chemistry, University of Florida,
Gainesville, Florida, 32611 United States
- Correspondence to:
, ,
| | | | | | - Tommy Yunpu Zhao
- Department of Chemistry, University of Florida,
Gainesville, Florida, 32611 United States
| | - Yong Du
- Department of Chemistry, University of Florida,
Gainesville, Florida, 32611 United States
| | - Yuchen Pei
- Department of Chemistry, Iowa State University, Ames, Iowa,
50011 United States
| | - Wenyu Huang
- Department of Chemistry, Iowa State University, Ames, Iowa,
50011 United States
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa
50011 United States
- Correspondence to:
, ,
| | - Clifford Russell Bowers
- Department of Chemistry, University of Florida,
Gainesville, Florida, 32611 United States
- Correspondence to:
, ,
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18
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Brodrecht M, Kumari B, Thankamony ASSL, Breitzke H, Gutmann T, Buntkowsky G. Structural Insights into Peptides Bound to the Surface of Silica Nanopores. Chemistry 2019; 25:5214-5221. [DOI: 10.1002/chem.201805480] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Martin Brodrecht
- Institut für Physikalische ChemieTechnische Universität Darmstadt 64287 Darmstadt Germany
| | - Bharti Kumari
- Institut für Physikalische ChemieTechnische Universität Darmstadt 64287 Darmstadt Germany
| | | | - Hergen Breitzke
- Institut für Physikalische ChemieTechnische Universität Darmstadt 64287 Darmstadt Germany
| | - Torsten Gutmann
- Institut für Physikalische ChemieTechnische Universität Darmstadt 64287 Darmstadt Germany
| | - Gerd Buntkowsky
- Institut für Physikalische ChemieTechnische Universität Darmstadt 64287 Darmstadt Germany
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19
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Babucci M, Fang CY, Perez-Aguilar JE, Hoffman AS, Boubnov A, Guan E, Bare SR, Gates BC, Uzun A. Controlling catalytic activity and selectivity for partial hydrogenation by tuning the environment around active sites in iridium complexes bonded to supports. Chem Sci 2019; 10:2623-2632. [PMID: 30996978 PMCID: PMC6419936 DOI: 10.1039/c8sc05287e] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 01/08/2019] [Indexed: 01/31/2023] Open
Abstract
Single-site Ir(CO)2 complexes bonded to high-surface-area metal oxide supports, SiO2, TiO2, Fe2O3, CeO2, MgO, and La2O3, were synthesized by chemisorption of Ir(CO)2(acac) (acac = acetylacetonate) followed by coating with each of the following ionic liquids (ILs): 1-n-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF4], 1-n-butyl-3-methylimidazolium acetate, [BMIM][Ac], and 1-(3-cyanopropyl)-3-methylimidazolium dicyanamide, [CPMIM][DCA]. Extended X-ray absorption fine structure spectroscopy showed that site-isolated iridium was bonded to oxygen atoms of the support. Electron densities on the iridium enveloped by each IL sheath/support combination were characterized by carbonyl infrared spectroscopy of the iridium gem-dicarbonyls and by X-ray absorption near-edge structure data. The electron-donor/acceptor tendencies of both the support and IL determine the activity and selectivity of the catalysts for the hydrogenation of 1,3-butadiene, with electron-rich iridium being selective for partial hydrogenation. The results resolve the effects of the IL and support as ligands; for example, the effect of the IL becomes dominant when the support has a weak electron-donor character. The combined effects of supports and ILs as ligands offer broad opportunities for tuning catalytic properties of supported metal catalysts.
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Affiliation(s)
- Melike Babucci
- Department of Chemical and Biological Engineering , Koç University , Rumelifeneri Yolu , Sariyer 34450, Istanbul , Turkey .
- Koç University TÜPRAŞ Energy Center (KUTEM) , Koç University , Rumelifeneri Yolu , Sariyer 34450, Istanbul , Turkey
| | - Chia-Yu Fang
- Department of Materials Science and Engineering , University of California , Davis , California 95616 , USA
| | - Jorge E Perez-Aguilar
- Department of Chemical Engineering , University of California , Davis , California 95616 , USA .
| | - Adam S Hoffman
- SSRL , SLAC National Accelerator Laboratory , Menlo Park , CA 94025 , USA
| | - Alexey Boubnov
- SSRL , SLAC National Accelerator Laboratory , Menlo Park , CA 94025 , USA
| | - Erjia Guan
- Department of Materials Science and Engineering , University of California , Davis , California 95616 , USA
| | - Simon R Bare
- SSRL , SLAC National Accelerator Laboratory , Menlo Park , CA 94025 , USA
| | - Bruce C Gates
- Department of Chemical Engineering , University of California , Davis , California 95616 , USA .
| | - Alper Uzun
- Department of Chemical and Biological Engineering , Koç University , Rumelifeneri Yolu , Sariyer 34450, Istanbul , Turkey .
- Koç University TÜPRAŞ Energy Center (KUTEM) , Koç University , Rumelifeneri Yolu , Sariyer 34450, Istanbul , Turkey
- Koç University Surface Science and Technology Center (KUYTAM) , Koç University , Rumelifeneri Yolu , Sariyer, 34450 Istanbul , Turkey
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20
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21
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Nevzorov AA, Milikisiyants S, Marek AN, Smirnov AI. Multi-resonant photonic band-gap/saddle coil DNP probehead for static solid state NMR of microliter volume samples. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 297:113-123. [PMID: 30380458 PMCID: PMC6894392 DOI: 10.1016/j.jmr.2018.10.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/18/2018] [Accepted: 10/20/2018] [Indexed: 05/04/2023]
Abstract
The most critical condition for performing Dynamic Nuclear Polarization (DNP) NMR experiments is achieving sufficiently high electronic B1e fields over the sample at the matched EPR frequencies, which for modern high-resolution NMR instruments fall into the millimeter wave (mmW) range. Typically, mmWs are generated by powerful gyrotrons and/or extended interaction klystrons (EIKs) sources and then focused onto the sample by dielectric lenses. However, further development of DNP methods including new DNP pulse sequences may require B1e fields higher than one could achieve with the current mmW technology. In order to address the challenge of significantly enhancing the mmW field at the sample, we have constructed and tested one-dimensional photonic band-gap (PBG) mmW resonator that was incorporated inside a double-tuned radiofrequency (rf) NMR saddle coil. The photonic crystal is formed by stacking ceramic discs with alternating high and low dielectric constants and thicknesses of λ/4 or 3λ/4, where λ is the wavelength of the incident mmW field in the corresponding dielectric material. When the mmW frequency is within the band gap of the photonic crystal, a defect created in the middle of the crystal confines the mmW energy, thus forming a resonant structure. An aluminum mirror in the middle of the defect has been used to substitute one-half of the structure with its mirror image in order to reduce the resonator size and simplify its tuning. The latter is achieved by adjusting the width of the defect by moving the aluminum mirror with respect to the dielectric stack using a gear mechanism. The 1D PBG resonator was the key element for constructing a multi-resonant integrated DNP/NMR probehead operating at 190-199 GHz EPR/300 MHz 1H/75.5 MHz 13C NMR frequencies. Initial tests of the multi-resonant DNP/NMR probehead were carried out using a quasioptical mmW bridge and a Bruker Biospin Avance II spectrometer equipped with a standard Bruker 7 T wide-bore 89 mm magnet parked at 300.13 MHz 1H NMR frequency. The mmW bridge built with all solid-state active components allows for the frequency tuning between ca. 190 and ca. 199 GHz with the output power up to 27 dBm (0.5 W) at 192 GHz and up to 23 dBm (0.2 W) at 197.5 GHz. Room temperature DNP experiments with a synthetic single crystal high-pressure high-temperature (HPHT) diamond (0.3 × 0.3 × 3.0 mm3) demonstrated dramatic 1500-fold enhancement of 13C natural abundance NMR signal at full incident mmW power. Significant 13C DNP enhancement (of about 90) have been obtained at incident mmW powers of as low as <100 μW. Further tests of the resonator performance have been carried out with a thin (ca. 100 μm thickness) composite polystyrene-microdiamond film by controlling the average mmW power at the optimal DNP conditions via a gated mode of operation. From these experiments, the PBG resonator with loaded Q ≃ 250 and finesse F≈75 provides up to 12-fold or 11 db gain in the average mmW power vs. the non-resonant probehead configuration employing only a reflective mirror.
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Affiliation(s)
- Alexander A Nevzorov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
| | - Sergey Milikisiyants
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Antonin N Marek
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
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22
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Xiao D, Xu S, Brownbill NJ, Paul S, Chen LH, Pawsey S, Aussenac F, Su BL, Han X, Bao X, Liu Z, Blanc F. Fast detection and structural identification of carbocations on zeolites by dynamic nuclear polarization enhanced solid-state NMR. Chem Sci 2018; 9:8184-8193. [PMID: 30568769 PMCID: PMC6254210 DOI: 10.1039/c8sc03848a] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/02/2018] [Indexed: 12/20/2022] Open
Abstract
Acidic zeolites are porous aluminosilicates used in a wide range of industrial processes such as adsorption and catalysis. The formation of carbocation intermediates plays a key role in reactivity, selectivity and deactivation in heterogeneous catalytic processes. However, the observation and determination of carbocations remain a significant challenge in heterogeneous catalysis due to the lack of selective techniques of sufficient sensitivity to detect their low concentrations. Here, we combine 13C isotopic enrichment and efficient dynamic nuclear polarization magic angle spinning nuclear magnetic resonance spectroscopy to detect carbocations in zeolites. We use two dimensional 13C-13C through-bond correlations to establish their structures and 29Si-13C through-space experiments to quantitatively probe the interaction between multiple surface sites of the zeolites and the confined hydrocarbon pool species. We show that a range of various membered ring carbocations are intermediates in the methanol to hydrocarbons reaction catalysed by different microstructural β-zeolites and highlight that different reaction routes for the formation of both targeted hydrocarbon products and coke exist. These species have strong van der Waals interaction with the zeolite framework demonstrating that their accumulation in the channels of the zeolites leads to deactivation. These results enable understanding of deactivation pathways and open up opportunities for the design of catalysts with improved performances.
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Affiliation(s)
- Dong Xiao
- State Key Laboratory of Catalysis , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , 457 Zhongshan Road , Dalian 116023 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
- Department of Chemistry , University of Liverpool , Crown Street , Liverpool , L69 7ZD , UK .
| | - Shutao Xu
- National Engineering Laboratory for Methanol to Olefins , Dalian National Laboratory for Clean Energy , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , Dalian 116023 , China
| | - Nick J Brownbill
- Department of Chemistry , University of Liverpool , Crown Street , Liverpool , L69 7ZD , UK .
| | - Subhradip Paul
- DNP MAS NMR Facility , Sir Peter Mansfield Imaging Centre , University of Nottingham , Nottingham NG7 2RD , UK
| | - Li-Hua Chen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , 122 Luoshi Road , 430070 , Wuhan , China
| | - Shane Pawsey
- Bruker BioSpin Corporation , 15 Fortune Drive , Billerica , Massachusetts 01821 , USA
| | - Fabien Aussenac
- Bruker BioSpin , 34 rue de I'Industrie BP 10002 , 67166 Wissembourg Cedex , France
| | - Bao-Lian Su
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , 122 Luoshi Road , 430070 , Wuhan , China
- CMI (Laboratory of Inorganic Materials Chemistry) , University of Namur , 61 rue de Bruxelles , B-5000 Namur , Belgium
| | - Xiuwen Han
- State Key Laboratory of Catalysis , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , 457 Zhongshan Road , Dalian 116023 , China
| | - Xinhe Bao
- State Key Laboratory of Catalysis , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , 457 Zhongshan Road , Dalian 116023 , China
| | - Zhongmin Liu
- State Key Laboratory of Catalysis , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , 457 Zhongshan Road , Dalian 116023 , China
- National Engineering Laboratory for Methanol to Olefins , Dalian National Laboratory for Clean Energy , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , Dalian 116023 , China
| | - Frédéric Blanc
- Department of Chemistry , University of Liverpool , Crown Street , Liverpool , L69 7ZD , UK .
- Stephenson Institute for Renewable Energy , University of Liverpool , Crown Street , Liverpool L69 7ZD , UK
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23
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Leavesley A, Jain S, Kamniker I, Zhang H, Rajca S, Rajca A, Han S. Maximizing NMR signal per unit time by facilitating the e-e-n cross effect DNP rate. Phys Chem Chem Phys 2018; 20:27646-27657. [PMID: 30375593 PMCID: PMC6370975 DOI: 10.1039/c8cp04909b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dynamic nuclear polarization (DNP) efficiency is critically dependent on the properties of the radical, solvent, and solute constituting the sample system. In this study, we focused on the three spin e-e-n cross effect (CE)'s influence on the nuclear longitudinal relaxation time constant T1n, the build-up time constants of nuclear magnetic resonance (NMR) signal, TDNP and DNP-enhancement of NMR signal. The dipolar interaction strength between the electron spins driving the e-e-n process was systematically modulated using mono-, di-, tri-, and dendritic-nitroxide radicals, while maintaining a constant global electron spin concentration of 10 mM. Experimental results showed that an increase in electron spin clustering led to an increased electron spin depolarization, as mapped by electron double resonance (ELDOR), and a dramatically shortened T1n and TDNP time constants under static and magic angle spinning (MAS) conditions. A theoretical analysis reveals that strong e-e interactions, caused by electron spin clustering, increase the CE rate. The three spin e-e-n CE is a hitherto little recognized mechanism for shortening T1n and TDNP in solid-state NMR experiments at cryogenic temperatures, and offers a design principle to enhance the effective CE DNP enhancement per unit time. Fast CE rates will benefit DNP at liquid helium temperatures, or at higher magnetic fields and pulsed DNP, where slow e-e-n polarization transfer rate is a key bottleneck to achieving maximal DNP performance.
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Affiliation(s)
- Alisa Leavesley
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA
| | - Sheetal Jain
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA
| | - Ilia Kamniker
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA
| | - Hui Zhang
- Department of Chemistry, University of Nebraska, Lincoln, NE
| | - Suchada Rajca
- Department of Chemistry, University of Nebraska, Lincoln, NE
| | - Andrzej Rajca
- Department of Chemistry, University of Nebraska, Lincoln, NE
| | - Songi Han
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA
- Department of Chemical Engineering, University of California, Santa Barbara, CA
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24
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Wisser D, Karthikeyan G, Lund A, Casano G, Karoui H, Yulikov M, Menzildjian G, Pinon AC, Purea A, Engelke F, Chaudhari SR, Kubicki D, Rossini AJ, Moroz IB, Gajan D, Copéret C, Jeschke G, Lelli M, Emsley L, Lesage A, Ouari O. BDPA-Nitroxide Biradicals Tailored for Efficient Dynamic Nuclear Polarization Enhanced Solid-State NMR at Magnetic Fields up to 21.1 T. J Am Chem Soc 2018; 140:13340-13349. [DOI: 10.1021/jacs.8b08081] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dorothea Wisser
- Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | | | - Alicia Lund
- Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Gilles Casano
- AixMarseille Univ, CNRS, ICR, 13013 Marseille, France
| | - Hakim Karoui
- AixMarseille Univ, CNRS, ICR, 13013 Marseille, France
| | - Maxim Yulikov
- Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland
| | - Georges Menzildjian
- Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Arthur C. Pinon
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | | | | | - Sachin R. Chaudhari
- Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Dominik Kubicki
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Aaron J. Rossini
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Ilia B. Moroz
- Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland
| | - David Gajan
- Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland
| | - Gunnar Jeschke
- Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland
| | - Moreno Lelli
- Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy
- Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Anne Lesage
- Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Olivier Ouari
- AixMarseille Univ, CNRS, ICR, 13013 Marseille, France
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25
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Rossini AJ. Materials Characterization by Dynamic Nuclear Polarization-Enhanced Solid-State NMR Spectroscopy. J Phys Chem Lett 2018; 9:5150-5159. [PMID: 30107121 DOI: 10.1021/acs.jpclett.8b01891] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
High-resolution solid-state NMR spectroscopy is a powerful tool for the study of organic and inorganic materials because it can directly probe the symmetry and structure at nuclear sites, the connectivity/bonding of atoms and precisely measure interatomic distances. However, NMR spectroscopy is hampered by intrinsically poor sensitivity; consequently, the application of NMR spectroscopy to many solid materials is often infeasible. High-field dynamic nuclear polarization (DNP) has emerged as a technique to routinely enhance the sensitivity of solid-state NMR experiments by 1-3 orders of magnitude. This Perspective gives a general overview of how DNP-enhanced solid-state NMR spectroscopy can be applied to a variety of inorganic and organic materials. DNP-enhanced solid-state NMR experiments provide unique insights into the molecular structure, which makes it possible to form structure-activity relationships that ultimately assist in the rational design and improvement of materials.
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Affiliation(s)
- Aaron J Rossini
- Department of Chemistry , Iowa State University , Ames , Iowa 50011 , United States
- U.S. DOE Ames Laboratory , Ames , Iowa 50011 , United States
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26
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Fu R, Hernández-Maldonado AJ. Boosting sensitivity and suppressing artifacts via multi-acquisition in direct polarization NMR experiments with small flip-angle pulses. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 293:34-40. [PMID: 29890484 DOI: 10.1016/j.jmr.2018.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/19/2018] [Accepted: 05/23/2018] [Indexed: 06/08/2023]
Abstract
A small flip-angle pulse direct polarization is the simplest method commonly used to quantify various compositions in many materials applications. This method sacrifices the sensitivity per scan in exchange for rapid repeating of data acquisition for signal accumulation. In addition, the resulting spectrum often encounters artifacts from background signals from probe components and/or from acoustic rings leading to a distorted baseline, especially in low-γ nuclei and wideline NMR. In this work, a multi-acquisition scheme is proposed to boost the sensitivity per scan and at the same time effectively suppress these artifacts. Here, an adiabatic inversion pulse is first applied in order to bring the magnetization from the +z to -z axis and then a small flip-angle pulse excitation is used before the data acquisition. Right after the first acquisition, the adiabatic inversion pulse is applied again to flip the magnetization back to the +z axis. The second data acquisition takes place after another small flip-angle pulse excitation. The difference between the two consecutive acquisitions cancels out any artifacts, while the wanted signals are accumulated. This acquisition process can be repeated many times before going into next scan. Therefore, by acquiring the signals multiple times in a single scan the sensitivity is improved. A mixture sample of flufenamic acid and 3,5-difluorobenzoic acid and a titanium silicate sample have been used to demonstrate the advantages of this newly proposed method.
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Affiliation(s)
- Riqiang Fu
- National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310, United States.
| | - Arturo J Hernández-Maldonado
- Department of Chemical Engineering, University of Puerto Rico-Mayagüez Campus, Mayagüez, PR 00681-9000, United States
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27
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Pump E, Bendjeriou-Sedjerari A, Viger-Gravel J, Gajan D, Scotto B, Samantaray MK, Abou-Hamad E, Gurinov A, Almaksoud W, Cao Z, Lesage A, Cavallo L, Emsley L, Basset JM. Predicting the DNP-SENS efficiency in reactive heterogeneous catalysts from hydrophilicity. Chem Sci 2018; 9:4866-4872. [PMID: 29910939 PMCID: PMC5982197 DOI: 10.1039/c8sc00532j] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/16/2018] [Indexed: 12/17/2022] Open
Abstract
Identification of surfaces at the molecular level has benefited from progress in dynamic nuclear polarization surface enhanced NMR spectroscopy (DNP SENS).
Identification of surfaces at the molecular level has benefited from progress in dynamic nuclear polarization surface enhanced NMR spectroscopy (DNP SENS). However, the technique is limited when using highly sensitive heterogeneous catalysts due to secondary reaction of surface organometallic fragments (SOMFs) with stable radical polarization agents. Here, we observe that in non-porous silica nanoparticles (NPs) (dparticle = 15 nm) some DNP enhanced NMR or SENS characterizations are possible, depending on the metal-loading of the SOMF and the type of SOMF substituents (methyl, isobutyl, neopentyl). This unexpected observation suggests that aggregation of the nanoparticles occurs in non-polar solvents (such as ortho-dichlorobenzene) leading to (partial) protection of the SOMF inside the interparticle space, thereby preventing reaction with bulky polarization agents. We discover that the DNP SENS efficiency is correlated with the hydrophilicity of the SOMF/support, which depends on the carbon and SOMF concentration. Nitrogen sorption measurements to determine the BET constant (CBET) were performed. This constant allows us to predict the aggregation of silica nanoparticles and consequently the efficiency of DNP SENS. Under optimal conditions, CBET > 60, we found signal enhancement factors of up to 30.
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Affiliation(s)
- Eva Pump
- King Abdullah University of Science and Technology (KAUST) , KAUST Catalysis Center (KCC) , Thuwal , 23955-6900 , Saudi Arabia .
| | - Anissa Bendjeriou-Sedjerari
- King Abdullah University of Science and Technology (KAUST) , KAUST Catalysis Center (KCC) , Thuwal , 23955-6900 , Saudi Arabia .
| | - Jasmine Viger-Gravel
- Institut des Sciences et Ingénierie Chimiques , Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland .
| | - David Gajan
- Institut de Sciences Analytiques (CNRS/ENS-Lyon/UCB-Lyon 1) , Université de Lyon , Centre de RMN à Très Hauts Champs , 69100 Villeurbanne , France
| | - Baptiste Scotto
- King Abdullah University of Science and Technology (KAUST) , KAUST Catalysis Center (KCC) , Thuwal , 23955-6900 , Saudi Arabia .
| | - Manoja K Samantaray
- King Abdullah University of Science and Technology (KAUST) , KAUST Catalysis Center (KCC) , Thuwal , 23955-6900 , Saudi Arabia .
| | - Edy Abou-Hamad
- King Abdullah University of Science and Technology (KAUST) , Core Labs , Thuwal , 23955-6900 , Saudi Arabia
| | - Andrei Gurinov
- King Abdullah University of Science and Technology (KAUST) , Core Labs , Thuwal , 23955-6900 , Saudi Arabia
| | - Walid Almaksoud
- King Abdullah University of Science and Technology (KAUST) , KAUST Catalysis Center (KCC) , Thuwal , 23955-6900 , Saudi Arabia .
| | - Zhen Cao
- King Abdullah University of Science and Technology (KAUST) , KAUST Catalysis Center (KCC) , Thuwal , 23955-6900 , Saudi Arabia .
| | - Anne Lesage
- Institut de Sciences Analytiques (CNRS/ENS-Lyon/UCB-Lyon 1) , Université de Lyon , Centre de RMN à Très Hauts Champs , 69100 Villeurbanne , France
| | - Luigi Cavallo
- King Abdullah University of Science and Technology (KAUST) , KAUST Catalysis Center (KCC) , Thuwal , 23955-6900 , Saudi Arabia .
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques , Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland .
| | - Jean-Marie Basset
- King Abdullah University of Science and Technology (KAUST) , KAUST Catalysis Center (KCC) , Thuwal , 23955-6900 , Saudi Arabia .
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28
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Werghi B, Pump E, Tretiakov M, Abou-Hamad E, Gurinov A, Doggali P, Anjum DH, Cavallo L, Bendjeriou-Sedjerari A, Basset JM. Exploiting the interactions between the ruthenium Hoveyda-Grubbs catalyst and Al-modified mesoporous silica: the case of SBA15 vs. KCC-1. Chem Sci 2018; 9:3531-3537. [PMID: 29780484 PMCID: PMC5934738 DOI: 10.1039/c7sc05200f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/05/2018] [Indexed: 11/21/2022] Open
Abstract
2nd generation Hoveyda–Grubbs catalyst immobilized onto well-ordered 2D hexagonal (SBA15) and 3D fibrous (KCC-1) mesostructured silica displaying tetra-coordinated Al–H via Surface Organometallic Chemistry (SOMC).
Immobilization of the 2nd generation Hoveyda–Grubbs catalyst HG-II onto well-ordered 2D hexagonal (SBA15) and 3D fibrous (KCC-1) mesostructured silica, which contained tetra-coordinated Al, has been investigated through the Surface Organometallic Chemistry (SOMC) methodology. The main interest of this study lies in the peculiarity of the silica supports, which display a well-defined tetrahedral aluminum hydride site displaying a strong Lewis acid character, [(
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Si–O–Si
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Si–O–)2Al–H]. The resulting supported Hoveyda–Grubbs catalysts have been fully characterized by advanced solid state characterization techniques (FT-IR, 1H and 13C solid state NMR, DNP-SENS, EF-TEM…). Together with DFT calculations, the immobilization of HG-II does not occur through the formation of a covalent bond between the complex and the Al-modified mesoporous silica as expected, but through an Al···Cl–[Ru]-coordination. It is not surprising that in functionalized olefin metathesis of diethyldiallyl malonate, DEDAM (liquid phase), leaching of the catalyst is observed which is not the case in non-functionalized olefin metathesis of propene (gas phase). Besides, the results obtained in propene metathesis with HG-II immobilized either on SBA15 (dpore = 6 nm) or KCC-1 (dpore = 4 or 8 nm) highlight the importance of the accessibility of the catalytic site. Therefore, we demonstrate that KCC-1 is a promising and suitable 3D mesoporous support to overcome the diffusion of reactants into the porous network of heterogeneous catalysts.
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Affiliation(s)
- Baraa Werghi
- KAUST Catalysis Center (KCC) , King Abdullah University of Science and Technology , Thuwal , 23955-6900 , Saudi Arabia . ;
| | - Eva Pump
- KAUST Catalysis Center (KCC) , King Abdullah University of Science and Technology , Thuwal , 23955-6900 , Saudi Arabia . ;
| | - Mykyta Tretiakov
- KAUST Catalysis Center (KCC) , King Abdullah University of Science and Technology , Thuwal , 23955-6900 , Saudi Arabia . ;
| | - Edy Abou-Hamad
- King Abdullah University of Science and Technology (KAUST) , Core Labs , Thuwal , 23955-6900 , Saudi Arabia
| | - Andrei Gurinov
- King Abdullah University of Science and Technology (KAUST) , Core Labs , Thuwal , 23955-6900 , Saudi Arabia
| | - Pradeep Doggali
- KAUST Catalysis Center (KCC) , King Abdullah University of Science and Technology , Thuwal , 23955-6900 , Saudi Arabia . ;
| | - Dalaver H Anjum
- King Abdullah University of Science and Technology (KAUST) , Core Labs , Thuwal , 23955-6900 , Saudi Arabia
| | - Luigi Cavallo
- KAUST Catalysis Center (KCC) , King Abdullah University of Science and Technology , Thuwal , 23955-6900 , Saudi Arabia . ;
| | - Anissa Bendjeriou-Sedjerari
- KAUST Catalysis Center (KCC) , King Abdullah University of Science and Technology , Thuwal , 23955-6900 , Saudi Arabia . ;
| | - Jean-Marie Basset
- KAUST Catalysis Center (KCC) , King Abdullah University of Science and Technology , Thuwal , 23955-6900 , Saudi Arabia . ;
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29
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Kumari B, John D, Hoffmann P, Spende A, Toimil-Molares ME, Trautmann C, Hess C, Ruff P, Schulze M, Stark R, Buntkowsky G, Andrieu-Brunsen A, Gutmann T. Surface Enhanced DNP Assisted Solid-State NMR of Functionalized SiO2 Coated Polycarbonate Membranes. Z PHYS CHEM 2018. [DOI: 10.1515/zpch-2017-1032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Abstract
Surface enhanced solid-state NMR by dynamic nuclear polarization (DNP SENS) enables the characterization of the inner-pore surface functionalization of porous etched ion-track membranes exhibiting low specific surface areas compared to typical SBA- or MCM-type mesoporous silica materials. The membranes were conformally coated with a 5 nm thin SiO2 layer by atomic layer deposition. This layer was subsequently modified by aminopropyl silane linkers that allow further functionalization via the terminal amine group. The results evidence that in principle DNP SENS is a capable tool to analyze more complex porous systems, e.g. bioinspired functional etched ion-track membranes down to the molecular level. These results are relevant also for single nanopore systems, for which a direct analysis of the channel surface functionalization is not feasible by classical characterization methods. The applicability of DNP SENS to complex porous systems requires the optimization of the sample preparation and measurement parameters.
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Affiliation(s)
- Bharti Kumari
- Eduard-Zintl Institute for Inorganic and Physical Chemistry , Technische Universität Darmstadt , Alarich-Weiss-Str. 8 , D-64287 Darmstadt , Germany
| | - Daniel John
- Ernst-Berl Institute for Chemical Engineering and Macromolecular Science , Technische Universität Darmstadt , Alarich-Weiss-Str. 4 , D-64287 Darmstadt , Germany
| | - Paul Hoffmann
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1 , D-64291 Darmstadt , Germany
- Materialwissenschaft, Technische Universität Darmstadt , Alarich-Weiss-Str. 2 , D-64287 Darmstadt , Germany
| | - Anne Spende
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1 , D-64291 Darmstadt , Germany
- Materialwissenschaft, Technische Universität Darmstadt , Alarich-Weiss-Str. 2 , D-64287 Darmstadt , Germany
| | | | - Christina Trautmann
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1 , D-64291 Darmstadt , Germany
- Materialwissenschaft, Technische Universität Darmstadt , Alarich-Weiss-Str. 2 , D-64287 Darmstadt , Germany
| | - Christian Hess
- Eduard-Zintl Institute for Inorganic and Physical Chemistry , Technische Universität Darmstadt , Alarich-Weiss-Str. 8 , D-64287 Darmstadt , Germany
| | - Philip Ruff
- Eduard-Zintl Institute for Inorganic and Physical Chemistry , Technische Universität Darmstadt , Alarich-Weiss-Str. 8 , D-64287 Darmstadt , Germany
| | - Marcus Schulze
- Physics of Surfaces, Institute of Materials Science and Center of Smart Interfaces , Technische Universität Darmstadt , Alarich-Weiss-Str. 16 , D-64287 Darmstadt , Germany
| | - Robert Stark
- Physics of Surfaces, Institute of Materials Science and Center of Smart Interfaces , Technische Universität Darmstadt , Alarich-Weiss-Str. 16 , D-64287 Darmstadt , Germany
| | - Gerd Buntkowsky
- Eduard-Zintl Institute for Inorganic and Physical Chemistry , Technische Universität Darmstadt , Alarich-Weiss-Str. 8 , D-64287 Darmstadt , Germany
| | - Annette Andrieu-Brunsen
- Ernst-Berl Institute for Chemical Engineering and Macromolecular Science , Technische Universität Darmstadt , Alarich-Weiss-Str. 4 , D-64287 Darmstadt , Germany
| | - Torsten Gutmann
- Eduard-Zintl Institute for Inorganic and Physical Chemistry , Technische Universität Darmstadt , Alarich-Weiss-Str. 8 , D-64287 Darmstadt , Germany
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30
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Liao WC, Ghaffari B, Gordon CP, Xu J, Copéret C. Dynamic Nuclear Polarization Surface Enhanced NMR spectroscopy (DNP SENS): Principles, protocols, and practice. Curr Opin Colloid Interface Sci 2018. [DOI: 10.1016/j.cocis.2018.02.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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31
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Perras FA, Boteju KC, Slowing II, Sadow AD, Pruski M. Direct 17O dynamic nuclear polarization of single-site heterogeneous catalysts. Chem Commun (Camb) 2018; 54:3472-3475. [DOI: 10.1039/c8cc00293b] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Direct DNP is shown to effectively enhance 17O signals from non-protonated binding sites for surface-supported catalysts.
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Affiliation(s)
| | | | | | | | - Marek Pruski
- US DOE
- Ames Laboratory
- Ames
- USA
- Department of Chemistry
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32
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Samantaray MK, Pump E, Bendjeriou-Sedjerari A, D’Elia V, Pelletier JDA, Guidotti M, Psaro R, Basset JM. Surface organometallic chemistry in heterogeneous catalysis. Chem Soc Rev 2018; 47:8403-8437. [DOI: 10.1039/c8cs00356d] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Surface organometallic chemistry has been reviewed with a special focus on environmentally relevant transformations (C–H activation, CO2conversion, oxidation).
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Affiliation(s)
- Manoja K. Samantaray
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC)
- Thuwal
- Saudi Arabia
| | - Eva Pump
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC)
- Thuwal
- Saudi Arabia
| | | | - Valerio D’Elia
- Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology
- WangChan
- Thailand
| | - Jérémie D. A. Pelletier
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC)
- Thuwal
- Saudi Arabia
| | - Matteo Guidotti
- CNR – Institute of Molecular Sciences and Technologies
- 20133 Milano
- Italy
| | - Rinaldo Psaro
- CNR – Institute of Molecular Sciences and Technologies
- 20133 Milano
- Italy
| | - Jean-Marie Basset
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC)
- Thuwal
- Saudi Arabia
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33
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Pump E, Cao Z, Samantaray MK, Bendjeriou-Sedjerari A, Cavallo L, Basset JM. Exploiting Confinement Effects to Tune Selectivity in Cyclooctane Metathesis. ACS Catal 2017. [DOI: 10.1021/acscatal.7b01249] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eva Pump
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC), Thuwal, 23955-6900, Saudi Arabia
| | - Zhen Cao
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC), Thuwal, 23955-6900, Saudi Arabia
| | - Manoja K. Samantaray
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC), Thuwal, 23955-6900, Saudi Arabia
| | - Anissa Bendjeriou-Sedjerari
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC), Thuwal, 23955-6900, Saudi Arabia
| | - Luigi Cavallo
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC), Thuwal, 23955-6900, Saudi Arabia
| | - Jean-Marie Basset
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC), Thuwal, 23955-6900, Saudi Arabia
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34
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Ni QZ, Yang F, Can TV, Sergeyev IV, D’Addio SM, Jawla SK, Li Y, Lipert MP, Xu W, Williamson RT, Leone A, Griffin RG, Su Y. In Situ Characterization of Pharmaceutical Formulations by Dynamic Nuclear Polarization Enhanced MAS NMR. J Phys Chem B 2017; 121:8132-8141. [PMID: 28762740 PMCID: PMC5592962 DOI: 10.1021/acs.jpcb.7b07213] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A principal advantage of magic angle spinning (MAS) NMR spectroscopy lies in its ability to determine molecular structure in a noninvasive and quantitative manner. Accordingly, MAS should be widely applicable to studies of the structure of active pharmaceutical ingredients (API) and formulations. However, the low sensitivity encountered in spectroscopy of natural abundance APIs present at low concentration has limited the success of MAS experiments. Dynamic nuclear polarization (DNP) enhances NMR sensitivity and can be used to circumvent this problem provided that suitable paramagnetic polarizing agent can be incorporated into the system without altering the integrity of solid dosages. Here, we demonstrate that DNP polarizing agents can be added in situ during the preparation of amorphous solid dispersions (ASDs) via spray drying and hot-melt extrusion so that ASDs can be examined during drug development. Specifically, the dependence of DNP enhancement on sample composition, radical concentration, relaxation properties of the API and excipients, types of polarizing agents and proton density, has been thoroughly investigated. Optimal enhancement values are obtained from ASDs containing 1% w/w radical concentration. Both polarizing agents TOTAPOL and AMUPol provided reasonable enhancements. Partial deuteration of the excipient produced 3× higher enhancement values. With these parameters, an ASD containing posaconazole and vinyl acetate yields a 32-fold enhancement which presumably results in a reduction of NMR measurement time by ∼1000. This boost in signal intensity enables the full assignment of the natural abundance pharmaceutical formulation through multidimensional correlation experiments.
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Affiliation(s)
- Qing Zhe Ni
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Fengyuan Yang
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Thach V. Can
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Ivan V. Sergeyev
- Bruker BioSpin Corporation, Billerica, Massachusetts 01821, United States
| | - Suzanne M. D’Addio
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Sudheer K. Jawla
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Yongjun Li
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Maya P. Lipert
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Wei Xu
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - R. Thomas Williamson
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Anthony Leone
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Robert G. Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Yongchao Su
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
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35
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Chaudhari S, Wisser D, Pinon AC, Berruyer P, Gajan D, Tordo P, Ouari O, Reiter C, Engelke F, Copéret C, Lelli M, Lesage A, Emsley L. Dynamic Nuclear Polarization Efficiency Increased by Very Fast Magic Angle Spinning. J Am Chem Soc 2017; 139:10609-10612. [PMID: 28692804 PMCID: PMC5719465 DOI: 10.1021/jacs.7b05194] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Indexed: 12/03/2022]
Abstract
Dynamic nuclear polarization (DNP) has recently emerged as a tool to enhance the sensitivity of solid-state NMR experiments. However, so far high enhancements (>100) are limited to relatively low magnetic fields, and DNP at fields higher than 9.4 T significantly drops in efficiency. Here we report solid-state Overhauser effect DNP enhancements of over 100 at 18.8 T. This is achieved through the unexpected discovery that enhancements increase rapidly with increasing magic angle spinning (MAS) rates. The measurements are made using 1,3-bisdiphenylene-2-phenylallyl dissolved in o-terphenyl at 40 kHz MAS. We introduce a source-sink diffusion model for polarization transfer which is capable of explaining the experimental observations. The advantage of this approach is demonstrated on mesoporous alumina with the acquisition of well-resolved DNP surface-enhanced 27Al cross-polarization spectra.
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Affiliation(s)
- Sachin
R. Chaudhari
- Institut
de Sciences Analytiques, Centre de RMN à Très Hauts
Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Dorothea Wisser
- Institut
de Sciences Analytiques, Centre de RMN à Très Hauts
Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Arthur C. Pinon
- Institut
des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Pierrick Berruyer
- Institut
de Sciences Analytiques, Centre de RMN à Très Hauts
Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - David Gajan
- Institut
de Sciences Analytiques, Centre de RMN à Très Hauts
Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Paul Tordo
- Aix-Marseille
Université, CNRS, ICR UMR 7273, 13397 Marseille, France
| | - Olivier Ouari
- Aix-Marseille
Université, CNRS, ICR UMR 7273, 13397 Marseille, France
| | | | | | - Christophe Copéret
- Department
of Chemistry and Applied Biosciences, ETH
Zürich, CH-8093 Zürich, Switzerland
| | - Moreno Lelli
- Center for
Magnetic Resonance, Department of Chemistry, University of Florence, 50019 Sesto Fiorentino (Firenze), Italy
| | - Anne Lesage
- Institut
de Sciences Analytiques, Centre de RMN à Très Hauts
Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1), 69100 Villeurbanne, France
| | - Lyndon Emsley
- Institut
des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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36
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Mohandas JC, Abou-Hamad E, Callens E, Samantaray MK, Gajan D, Gurinov A, Ma T, Ould-Chikh S, Hoffman AS, Gates BC, Basset JM. From single-site tantalum complexes to nanoparticles of Ta x N y and TaO x N y supported on silica: elucidation of synthesis chemistry by dynamic nuclear polarization surface enhanced NMR spectroscopy and X-ray absorption spectroscopy. Chem Sci 2017; 8:5650-5661. [PMID: 28989603 PMCID: PMC5621011 DOI: 10.1039/c7sc01365e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/08/2017] [Indexed: 11/30/2022] Open
Abstract
Air-stable catalysts consisting of tantalum nitride nanoparticles represented as a mixture of Ta x N y and TaO x N y with diameters in the range of 0.5 to 3 nm supported on highly dehydroxylated silica were synthesized from TaMe5 (Me = methyl) and dimeric Ta2(OMe)10 with guidance by the principles of surface organometallic chemistry (SOMC). Characterization of the supported precursors and the supported nanoparticles formed from them was carried out by IR, NMR, UV-Vis, extended X-ray absorption fine structure, and X-ray photoelectron spectroscopies complemented with XRD and high-resolution TEM, with dynamic nuclear polarization surface enhanced NMR spectroscopy being especially helpful by providing enhanced intensities of the signals of 1H, 13C, 29Si, and 15N at their natural abundances. The characterization data provide details of the synthesis chemistry, including evidence of (a) O2 insertion into Ta-CH3 species on the support and (b) a binuclear to mononuclear transformation of species formed from Ta2(OMe)10 on the support. A catalytic test reaction, cyclooctene epoxidation, was used to probe the supported nanoparticles, with 30% H2O2 serving as the oxidant. The catalysts gave selectivities up to 98% for the epoxide at conversions as high as 99% with a 3.4 wt% loading of Ta present as Ta x N y /TaO x N y .
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Affiliation(s)
- Janet C Mohandas
- King Abdullah University of Science & Technology , KAUST Catalysis Center (KCC) , 23955-6900 Thuwal , Saudi Arabia .
| | - Edy Abou-Hamad
- King Abdullah University of Science & Technology , KAUST Catalysis Center (KCC) , 23955-6900 Thuwal , Saudi Arabia .
| | - Emmanuel Callens
- King Abdullah University of Science & Technology , KAUST Catalysis Center (KCC) , 23955-6900 Thuwal , Saudi Arabia .
| | - Manoja K Samantaray
- King Abdullah University of Science & Technology , KAUST Catalysis Center (KCC) , 23955-6900 Thuwal , Saudi Arabia .
| | - David Gajan
- Institut de Sciences Analytiques (CNRS/ENS-Lyon/UCB-Lyon 1) , Université de Lyon , Centre de RMN à Très Hauts Champs , 69100 , Villeurbanne , France
| | - Andrei Gurinov
- King Abdullah University of Science & Technology , KAUST Catalysis Center (KCC) , 23955-6900 Thuwal , Saudi Arabia .
| | - Tao Ma
- Department of Chemical Engineering , University of California , Davis , California 95616 , USA .
| | - Samy Ould-Chikh
- King Abdullah University of Science & Technology , KAUST Catalysis Center (KCC) , 23955-6900 Thuwal , Saudi Arabia .
| | - Adam S Hoffman
- Department of Chemical Engineering , University of California , Davis , California 95616 , USA .
| | - Bruce C Gates
- Department of Chemical Engineering , University of California , Davis , California 95616 , USA .
| | - Jean-Marie Basset
- King Abdullah University of Science & Technology , KAUST Catalysis Center (KCC) , 23955-6900 Thuwal , Saudi Arabia .
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37
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Viger-Gravel J, Berruyer P, Gajan D, Basset JM, Lesage A, Tordo P, Ouari O, Emsley L. Frozen Acrylamide Gels as Dynamic Nuclear Polarization Matrices. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201703758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Jasmine Viger-Gravel
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); 1015 Lausanne Switzerland
| | - Pierrick Berruyer
- Université de Lyon; Institut des Sciences Analytiques (UMR 5280 CNRS/UCBL/ENS Lyon), Centre de RMN à Très Hauts Champs; 69100 Villeurbanne France
| | - David Gajan
- Université de Lyon; Institut des Sciences Analytiques (UMR 5280 CNRS/UCBL/ENS Lyon), Centre de RMN à Très Hauts Champs; 69100 Villeurbanne France
| | - Jean-Marie Basset
- King Abdullah University of Science and Technology (KAUST); KAUST Catalysis Center (KCC); Thuwal 23955-6900 Saudi Arabia
| | - Anne Lesage
- Université de Lyon; Institut des Sciences Analytiques (UMR 5280 CNRS/UCBL/ENS Lyon), Centre de RMN à Très Hauts Champs; 69100 Villeurbanne France
| | - Paul Tordo
- Aix Marseille Uni, CNRS, ICR UMR 7273; 13397 Marseille France
| | - Olivier Ouari
- Aix Marseille Uni, CNRS, ICR UMR 7273; 13397 Marseille France
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); 1015 Lausanne Switzerland
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38
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Copéret C, Liao WC, Gordon CP, Ong TC. Active Sites in Supported Single-Site Catalysts: An NMR Perspective. J Am Chem Soc 2017; 139:10588-10596. [DOI: 10.1021/jacs.6b12981] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Christophe Copéret
- Department of Chemistry and
Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, CH-8093 Zürich, Switzerland
| | - Wei-Chih Liao
- Department of Chemistry and
Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, CH-8093 Zürich, Switzerland
| | - Christopher P. Gordon
- Department of Chemistry and
Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, CH-8093 Zürich, Switzerland
| | - Ta-Chung Ong
- Department of Chemistry and
Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, CH-8093 Zürich, Switzerland
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39
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Perras FA, Sadow A, Pruski M. In Silico Design of DNP Polarizing Agents: Can Current Dinitroxides Be Improved? Chemphyschem 2017; 18:2279-2287. [DOI: 10.1002/cphc.201700299] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/07/2017] [Indexed: 12/18/2022]
Affiliation(s)
| | - Aaron Sadow
- US DOE Ames Laboratory Ames IA 50011 USA
- Department of Chemistry Iowa State University Ames IA 50011 USA
| | - Marek Pruski
- US DOE Ames Laboratory Ames IA 50011 USA
- Department of Chemistry Iowa State University Ames IA 50011 USA
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40
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Frozen Acrylamide Gels as Dynamic Nuclear Polarization Matrices. Angew Chem Int Ed Engl 2017; 56:8726-8730. [DOI: 10.1002/anie.201703758] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Indexed: 01/08/2023]
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41
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Silverio DL, van Kalkeren HA, Ong TC, Baudin M, Yulikov M, Veyre L, Berruyer P, Chaudhari S, Gajan D, Baudouin D, Cavaillès M, Vuichoud B, Bornet A, Jeschke G, Bodenhausen G, Lesage A, Emsley L, Jannin S, Thieuleux C, Copéret C. Tailored Polarizing Hybrid Solids with Nitroxide Radicals Localized in Mesostructured Silica Walls. Helv Chim Acta 2017. [DOI: 10.1002/hlca.201700101] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Daniel L. Silverio
- Department of Chemistry and Applied Biosciences; ETH Zürich; Vladimir-Prelog-Weg 1-5 CH-8093 Zürich
| | - Henri A. van Kalkeren
- Université de Lyon; Institut de Chimie de Lyon; LC2P2; UMR 5265 CNRS-CPE-Lyon-UCBL; CPE Lyon; 43 Bvd du 11 Novembre 1918 FR-69100 Villeurbanne
| | - Ta-Chung Ong
- Department of Chemistry and Applied Biosciences; ETH Zürich; Vladimir-Prelog-Weg 1-5 CH-8093 Zürich
| | - Mathieu Baudin
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
- Laboratoire des Biomolécules (LBM); Département de Chimie, Ecole Normale Supérieure; UPMC Université Paris 06; CNRS; PSL Research University; 24 rue Lhomond FR-75005 Paris
- Laboratoire des Biomolécules (LBM); Sorbonne Universités; UPMC Université Paris 06; Ecole Normale Supérieure; CNRS; FR-75005 Paris
| | - Maxim Yulikov
- Department of Chemistry and Applied Biosciences; ETH Zürich; Vladimir-Prelog-Weg 1-5 CH-8093 Zürich
| | - Laurent Veyre
- Université de Lyon; Institut de Chimie de Lyon; LC2P2; UMR 5265 CNRS-CPE-Lyon-UCBL; CPE Lyon; 43 Bvd du 11 Novembre 1918 FR-69100 Villeurbanne
| | - Pierrick Berruyer
- Institut des Sciences Analytiques; CRMN CNRS-ENS Lyon-UCBL; Université de Lyon; FR-69100 Villeurbanne
| | - Sachin Chaudhari
- Institut des Sciences Analytiques; CRMN CNRS-ENS Lyon-UCBL; Université de Lyon; FR-69100 Villeurbanne
| | - David Gajan
- Institut des Sciences Analytiques; CRMN CNRS-ENS Lyon-UCBL; Université de Lyon; FR-69100 Villeurbanne
| | - David Baudouin
- Université de Lyon; Institut de Chimie de Lyon; LC2P2; UMR 5265 CNRS-CPE-Lyon-UCBL; CPE Lyon; 43 Bvd du 11 Novembre 1918 FR-69100 Villeurbanne
| | - Matthieu Cavaillès
- Université de Lyon; Institut de Chimie de Lyon; LC2P2; UMR 5265 CNRS-CPE-Lyon-UCBL; CPE Lyon; 43 Bvd du 11 Novembre 1918 FR-69100 Villeurbanne
| | - Basile Vuichoud
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
| | - Aurélien Bornet
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
| | - Gunnar Jeschke
- Department of Chemistry and Applied Biosciences; ETH Zürich; Vladimir-Prelog-Weg 1-5 CH-8093 Zürich
| | - Geoffrey Bodenhausen
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
- Laboratoire des Biomolécules (LBM); Département de Chimie, Ecole Normale Supérieure; UPMC Université Paris 06; CNRS; PSL Research University; 24 rue Lhomond FR-75005 Paris
- Laboratoire des Biomolécules (LBM); Sorbonne Universités; UPMC Université Paris 06; Ecole Normale Supérieure; CNRS; FR-75005 Paris
| | - Anne Lesage
- Institut des Sciences Analytiques; CRMN CNRS-ENS Lyon-UCBL; Université de Lyon; FR-69100 Villeurbanne
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
| | - Sami Jannin
- Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne (EPFL); CH-1015 Lausanne
- Institut des Sciences Analytiques; CRMN CNRS-ENS Lyon-UCBL; Université de Lyon; FR-69100 Villeurbanne
| | - Chloé Thieuleux
- Université de Lyon; Institut de Chimie de Lyon; LC2P2; UMR 5265 CNRS-CPE-Lyon-UCBL; CPE Lyon; 43 Bvd du 11 Novembre 1918 FR-69100 Villeurbanne
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences; ETH Zürich; Vladimir-Prelog-Weg 1-5 CH-8093 Zürich
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