1
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Stasiuk A, Peng P, Heller G, Cappellaro P. Frame change technique for phase transient cancellation. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 362:107688. [PMID: 38678738 DOI: 10.1016/j.jmr.2024.107688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 04/12/2024] [Accepted: 04/14/2024] [Indexed: 05/01/2024]
Abstract
The precise control of complex quantum mechanical systems can unlock applications ranging from quantum simulation to quantum computation. Controlling strongly interacting many-body systems often relies on Floquet Hamiltonian engineering that is achieved by fast switching between Hamiltonian primitives via external control. For example, in our solid-state NMR system, we perform quantum simulation by modulating the natural Hamiltonian with control pulses. As the Floquet heating errors scale with the interpulse delay, δt, it is favorable to keep δt as short as possible, forcing our control pulses to be short duration and high power. Additionally, high-power pulses help to minimize undesirable evolution from occurring during the duration of the pulse. However, such pulses introduce an appreciable phase-transient control error, a form of unitary error. In this work, we detail our ability to diagnose the error, calibrate its magnitude, and correct it for π/2-pulses of arbitrary phase. We demonstrate the improvements gained by correcting for the phase transient error, using a method which we call the "frame-change technique", in a variety of experimental settings of interest. Given that the correction mechanism adds no real control overhead, we recommend that any resonance probe be checked for these phase transient control errors, and correct them using the frame-change technique.
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Affiliation(s)
- Andrew Stasiuk
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA; Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA.
| | - Pai Peng
- Department of Electrical and Computer Engineering, Princeton University, Princeton, 08544, NJ, USA
| | - Garrett Heller
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Paola Cappellaro
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA; Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA; Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
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2
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Nimerovsky E, Soutar CP. A modification of γ-encoded RN symmetry pulses for increasing the scaling factor and more accurate measurements of the strong heteronuclear dipolar couplings. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 319:106827. [PMID: 32950918 DOI: 10.1016/j.jmr.2020.106827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 06/11/2023]
Abstract
Symmetry based γ-encoded RNnν elements are broadly used in magic-angle spinning solid-state NMR experiments to achieve selective recoupling of the heteronuclear dipolar interactions. The recoupled dipolar couplings in such experiments are scaled by a factor, Ksc, which theoretically depends on the chosen symmetry numbers N, n, and ν. However, the maximum theoretical value of Ksc for γ-encoded RNnν pulses is limited to ~0.25, resulting in long RNnν experiment times. Also, the dependence of Ksc on the experimental parameters can result in systematic errors in the experimental determination of the dipolar couplings, especially at low and moderate MAS rates. In this manuscript, we investigate the use of MODifiEd RNnν symmetry (MODERNnν(ϕM)) pulses that increase the dipolar scaling factor by at least 1.45 fold compared to γ-encoded RNnν. The second advantage of MODERNnν(ϕM) pulses with respect to traditional RNnν pulses is the reduced influence of experimental parameters on Ksc, which allows for more accurate measurement of short-range distances. The robustness of MODERNnν(ϕM) is compared with γ-encoded R1423 symmetry pulses. The enhanced performance is demonstrated on two uniformly-13C-enriched samples, N-acetyl valine and the microcrystalline protein GB1, at a 31.111 kHz MAS rate.
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Affiliation(s)
- Evgeny Nimerovsky
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Corinne P Soutar
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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3
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Sørensen JJ, Nyemann JS, Motzoi F, Sherson J, Vosegaard T. Optimization of pulses with low bandwidth for improved excitation of multiple-quantum coherences in NMR of quadrupolar nuclei. J Chem Phys 2020; 152:054104. [DOI: 10.1063/1.5141384] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jens Jakob Sørensen
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Jacob Søgaard Nyemann
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
- Interdisciplinary Nanoscience Center and Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark
| | - Felix Motzoi
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
- Forschungszentrum Jülich, Institute of Quantum Control (PGI-8), D-52425 Jülich, Germany
| | - Jacob Sherson
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Thomas Vosegaard
- Interdisciplinary Nanoscience Center and Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark
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4
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Amouzandeh G, Ramaswamy V, Freytag N, Edison AS, Hornak LA, Brey WW. Time and Frequency Domain Response of HTS Resonators for Use as NMR Transmit Coils. IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY : A PUBLICATION OF THE IEEE SUPERCONDUCTIVITY COMMITTEE 2019; 29:1102705. [PMID: 31857782 PMCID: PMC6921929 DOI: 10.1109/tasc.2019.2902522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Replacing normal metal NMR coils with thin-film high-temperature superconductor (HTS) resonators can significantly improve the sensitivity of analytical NMR. To study the use of these resonators for excitation as well as detection, we investigated the radio frequency properties of the HTS NMR coils in both frequency and time domain at a variety of transmit power levels. Experiments were conducted on a double-sided, counter wound spiral resonator designed to detect NMR signals from 13C nuclei at 14.1 T. Power-dependent nonlinearity was observed in the transmission coefficient and quality factor. The ability of the HTS resonators to accurately generate short pulses was studied in the time domain over the range power levels. The results of this study show that some form of Q switching is needed to get good transmit performance from HTS coils for 13C. For that purpose, the effect of adding a shorted transmission line stub to improve the pulse shapes and reduce phase transients was studied.
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Affiliation(s)
- Ghoncheh Amouzandeh
- National High Magnetic Laboratory and the Department of Physics, Florida State University, Tallahassee, FL 32310 USA
| | | | | | | | | | - William W Brey
- National High Magnetic Laboratory, Florida State University, Tallahassee, FL 32310 USA
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5
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Mangstl M, Wied JK, Weber J, Pritzel C, Trettin R, Schmedt auf der Günne J. Synthesis and characterization of methylammonium phosphates as crystalline approximants for anhydrous, low melting phosphate glasses. RSC Adv 2019; 9:1822-1830. [PMID: 35516152 PMCID: PMC9059716 DOI: 10.1039/c8ra07736c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 12/27/2018] [Indexed: 01/26/2023] Open
Abstract
Low-melting methylammonium phosphate glasses are synthesized from crystalline starting agents. To this end crystalline tris(methylammonium) cyclotriphosphate [CH3NH3]3P3O9, was synthesized by a novel and simple synthesis route from P4O10 and N-methylformamide. It, undergoes an irreversible phase transition to methylammonium catena-polyphosphate [CH3NH3]PO3. The crystal structure of the catena-polyphosphate was solved and refined from X-ray powder diffraction data by the Rietveld method using constraints obtained by solid-state 31P and 1H NMR spectroscopy. This compound crystallizes in a triclinic space group with a = 13.2236(9), b = 7.8924(6), c = 4.6553(2) Å, α = 91.068(4), β = 87.840(5) and γ = 106.550(3)°. Quantum chemical calculations confirm that the obtained structure lies at an energetic minimum. Finally the reaction of tris(methylammonium) cyclotriphosphate and P4O10 into methylammonium phosphate glass is presented. The synthesized, water-free phosphate glass shows a very low glass transition temperature Tg of 33 °C, which was verified by dynamic scanning calorimetry and NMR. The chain-like crystal structure of the high-temperature methylammoniumphosphate [CH3NH3]PO3 serves as an approximation for the short-range order of the glass. The novel glass shows the lowest glass transition temperature known for binary phosphate glass systems without acidic protons.![]()
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Affiliation(s)
- Martin Mangstl
- Inorganic Materials Chemistry
- Universität Siegen
- 57076 Siegen
- Germany
| | - Jan Konrad Wied
- Inorganic Materials Chemistry
- Universität Siegen
- 57076 Siegen
- Germany
| | - Johannes Weber
- Inorganic Materials Chemistry
- Universität Siegen
- 57076 Siegen
- Germany
| | - Christian Pritzel
- Institute for Building and Materials Chemistry
- Universität Siegen
- 57076 Siegen
- Germany
| | - Reinhard Trettin
- Institute for Building and Materials Chemistry
- Universität Siegen
- 57076 Siegen
- Germany
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6
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Hellwagner J, Wili N, Ibáñez LF, Wittmann JJ, Meier BH, Ernst M. Transient effects in π-pulse sequences in MAS solid-state NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 287:65-73. [PMID: 29289819 DOI: 10.1016/j.jmr.2017.12.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 12/12/2017] [Accepted: 12/19/2017] [Indexed: 06/07/2023]
Abstract
Dipolar recoupling techniques that use isolated rotor-synchronized π pulses are commonly used in solid-state NMR spectroscopy to gain insight into the structure of biological molecules. These sequences excel through their simplicity, stability towards radio-frequency (rf) inhomogeneity, and low rf requirements. For a theoretical understanding of such sequences, we present a Floquet treatment based on an interaction-frame transformation including the chemical-shift offset dependence. This approach is applied to the homonuclear dipolar-recoupling sequence Radio-Frequency Driven Recoupling (RFDR) and the heteronuclear recoupling sequence Rotational Echo Double Resonance (REDOR). Based on the Floquet approach, we show the influence of effective fields caused by pulse transients and discuss the advantages of pulse-transient compensation. We demonstrate experimentally that the transfer efficiency for homonuclear recoupling can be doubled in some cases in model compounds as well as in simple peptides if pulse-transient compensation is applied to the π pulses. Additionally, we discuss the influence of various phase cycles on the recoupling efficiency in order to reduce the magnitude of effective fields. Based on the findings from RFDR, we are able to explain why the REDOR sequence does not suffer in the recoupling efficiency despite the presence of effective fields.
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Affiliation(s)
- Johannes Hellwagner
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Nino Wili
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | | | - Johannes J Wittmann
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Beat H Meier
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland.
| | - Matthias Ernst
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland.
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7
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Neuberger S, Culver SP, Eckert H, Zeier WG, Schmedt auf der Günne J. Refinement of the crystal structure of Li4P2S6 using NMR crystallography. Dalton Trans 2018; 47:11691-11695. [DOI: 10.1039/c8dt02619j] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a new structural model for Li4P2S6 derived from 31P MAS NMR and XRD data, symmetry relations and quantum-chemical calculations.
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Affiliation(s)
- Sven Neuberger
- Inorganic Materials Chemistry
- University of Siegen
- 57076 Siegen
- Germany
| | - Sean P. Culver
- Institute of Physical Chemistry
- Justus-Liebig-University Giessen
- D-35392 Giessen
- Germany
| | - Hellmut Eckert
- Institute of Physics in São Carlos
- University of São Paulo
- Sao Carlos
- Brazil
- Institute of Physical Chemistry
| | - Wolfgang G. Zeier
- Institute of Physical Chemistry
- Justus-Liebig-University Giessen
- D-35392 Giessen
- Germany
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8
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Mangstl M, Celinski VR, Pritzel C, Trettin R, Schmedt auf der Günne J. Irreversible Phase Transition of Bistetramethylammonium Hydrogencyclotriphosphate. Z Anorg Allg Chem 2017. [DOI: 10.1002/zaac.201700246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Martin Mangstl
- Inorganic Materials Chemistry University of Siegen Adolf‐Reichwein‐Straße 2 57076 Siegen Germany
| | - Vinicius R. Celinski
- Inorganic Materials Chemistry University of Siegen Adolf‐Reichwein‐Straße 2 57076 Siegen Germany
| | - Christian Pritzel
- Institute for Building and Materials Chemistry University of Siegen Paul‐Bonatz‐Straße 9–11 57076 Siegen Germany
| | - Reinhard Trettin
- Institute for Building and Materials Chemistry University of Siegen Paul‐Bonatz‐Straße 9–11 57076 Siegen Germany
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9
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Koos MRM, Feyrer H, Luy B. Broadband RF-amplitude-dependent flip angle pulses with linear phase slope. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:797-803. [PMID: 28321918 DOI: 10.1002/mrc.4593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/08/2017] [Accepted: 03/11/2017] [Indexed: 06/06/2023]
Abstract
Pulse sequences in NMR spectroscopy sometimes require the application of pulses with effective flip angles different from 90° and 180°. Previously (Magn. Reson. Chem. 2015, 53, 886-893), offset-compensated broadband excitation pulses with RF-amplitude-dependent effective flip angles (RADFA) were introduced that are applicable in such cases. However, especially RF-amplitude-restricted RADFA pulses turned out to perform not as good as desired in terms of achievable bandwidths. Here, a class of RF-amplitude-restricted RADFA pulses with linear phase slope is introduced that allows excitation over much larger bandwidths with better performance. In this theoretical work, the basic principle of the pulse class is explained, their physical limits explored, and their properties, also compared with other pulse classes, discussed in detail. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Martin R M Koos
- Institut für Biologische Grenzflächen 4 - Magnetische Resonanz, Karlsruher Institut für Technologie (KIT), Postfach 3640, 76021, Karlsruhe, Germany
| | - Hannes Feyrer
- Institut für Organische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
- Department of Medical Biochemistry and Biophysics (MBB), Karolinska Institutet, Scheeles Väg 2, 171 77, Stockholm, Sweden
| | - Burkhard Luy
- Institut für Biologische Grenzflächen 4 - Magnetische Resonanz, Karlsruher Institut für Technologie (KIT), Postfach 3640, 76021, Karlsruhe, Germany
- Institut für Organische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
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10
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Hellwagner J, Sharma K, Tan KO, Wittmann JJ, Meier BH, Madhu PK, Ernst M. Optimizing symmetry-based recoupling sequences in solid-state NMR by pulse-transient compensation and asynchronous implementation. J Chem Phys 2017; 146:244202. [PMID: 28668064 DOI: 10.1063/1.4989542] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Pulse imperfections like pulse transients and radio-frequency field maladjustment or inhomogeneity are the main sources of performance degradation and limited reproducibility in solid-state nuclear magnetic resonance experiments. We quantitatively analyze the influence of such imperfections on the performance of symmetry-based pulse sequences and describe how they can be compensated. Based on a triple-mode Floquet analysis, we develop a theoretical description of symmetry-based dipolar recoupling sequences, in particular, R26411, calculating first- and second-order effective Hamiltonians using real pulse shapes. We discuss the various origins of effective fields, namely, pulse transients, deviation from the ideal flip angle, and fictitious fields, and develop strategies to counteract them for the restoration of full transfer efficiency. We compare experimental applications of transient-compensated pulses and an asynchronous implementation of the sequence to a supercycle, SR26, which is known to be efficient in compensating higher-order error terms. We are able to show the superiority of R26 compared to the supercycle, SR26, given the ability to reduce experimental error on the pulse sequence by pulse-transient compensation and a complete theoretical understanding of the sequence.
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Affiliation(s)
- Johannes Hellwagner
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Kshama Sharma
- TIFR Centre for Interdisciplinary Sciences, 21 Brundavan Colony, Narsingi, Hyderabad 500075, India
| | - Kong Ooi Tan
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Johannes J Wittmann
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Beat H Meier
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - P K Madhu
- TIFR Centre for Interdisciplinary Sciences, 21 Brundavan Colony, Narsingi, Hyderabad 500075, India
| | - Matthias Ernst
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
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11
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Franssen WMJ, Rezus YLA, Kentgens APM. High radio-frequency field strength nutation NMR of quadrupolar nuclei. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 273:33-39. [PMID: 27741438 DOI: 10.1016/j.jmr.2016.09.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 09/07/2016] [Accepted: 09/25/2016] [Indexed: 06/06/2023]
Abstract
Owing to the introduction of microcoils, high RF field strength nutation NMR is a viable candidate for the study of quadrupolar nuclei with strong quadrupolar couplings, not accessible using contemporary NMR techniques. We show powder 23Na nutation spectra on sodium nitrite for RF field strengths of up to 1170kHz, that conform to theoretical predictions. For lanthanum fluoride powder, 139La nutation spectra taken at elevated RF field amplitudes show clear discrepancies when compared to the theory. These errors are shown to be mainly caused by pulse transients at the end of the pulse, which proved to be detrimental to the shape of the nutation spectra. Using a nutation pulse which ends in a sudden frequency jump, we show that these errors can be reduced, and nutation spectra that conform to theory can be readily acquired. This enables nutation NMR for the study of quadrupolar nuclei with a strong quadrupolar coupling, bridging the gap between NMR, which can only analyse nuclei with a weak to medium quadrupolar coupling, and NQR, were extensive searching for the right quadrupolar frequency is the limiting factor.
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Affiliation(s)
- W M J Franssen
- Radboud University, Institute for Molecules and Materials (IMM), Solid State NMR, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Y L A Rezus
- Radboud University, Institute for Molecules and Materials (IMM), Solid State NMR, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - A P M Kentgens
- Radboud University, Institute for Molecules and Materials (IMM), Solid State NMR, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
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12
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Celinski VR, Ditter M, Kraus F, Fujara F, Schmedt auf der Günne J. Trace Determination and Pressure Estimation of Fluorine F2Caused by Irradiation Damage in Minerals and Synthetic Fluorides. Chemistry 2016; 22:18388-18393. [DOI: 10.1002/chem.201603402] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Vinicius R. Celinski
- Department für Chemie und Biologie; Universität Siegen; Adolf-Reichwein-Straße 2 57080 Siegen Germany
| | - Michael Ditter
- Fachbereich Physik; Technische Universität Darmstadt; Hochschulstraße 6 64289 Darmstadt Germany
| | - Florian Kraus
- Fachbereich Chemie; Phillipps-Universität Marburg; Hans-Meerwein-Straße 4 35032 Marburg Germany
| | - Franz Fujara
- Fachbereich Physik; Technische Universität Darmstadt; Hochschulstraße 6 64289 Darmstadt Germany
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13
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Wittmann JJ, Mertens V, Takeda K, Meier BH, Ernst M. Quantification and compensation of the influence of pulse transients on symmetry-based recoupling sequences. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 263:7-18. [PMID: 26766289 DOI: 10.1016/j.jmr.2015.12.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 12/08/2015] [Accepted: 12/16/2015] [Indexed: 06/05/2023]
Abstract
Deviations of amplitude and phase of radio-frequency pulses from the desired values, can have a severe impact on the performance of multiple-pulse sequences in NMR spectroscopy. A particular problem are pulse transients that appear every time there is a discontinuity in amplitude or phase. Based on a Floquet description using pulses with arbitrarily shaped amplitudes and phases we present a systematic study of the influence of pulse transients on symmetry-based pulse sequences in solid-state NMR under magic-angle spinning. This treatment explains the dependence of the experimentally observed transfer efficiency on the details of experimental setups. In addition, three approaches are compared which have the aim to re-establish highly efficient recoupling. We demonstrate that the application of transient-compensated pulses as basic elements of symmetry-based sequences leads to a significantly improved robustness of the experiments with respect to variations in the experimental setup.
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Affiliation(s)
- Johannes J Wittmann
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Valerie Mertens
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Kazuyuki Takeda
- Division of Chemistry, Graduate School of Science, Kyoto University, 606-8502 Kyoto, Japan
| | - Beat H Meier
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland.
| | - Matthias Ernst
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland.
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14
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Wittmann JJ, Takeda K, Meier BH, Ernst M. Kompensation von Pulsimperfektionen in der Festkörper-NMR- Spektroskopie: ein Schlüssel zu verbesserter Reproduzierbarkeit und Effizienz. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201504782] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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15
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Wittmann JJ, Takeda K, Meier BH, Ernst M. Compensating Pulse Imperfections in Solid-State NMR Spectroscopy: A Key to Better Reproducibility and Performance. Angew Chem Int Ed Engl 2015; 54:12592-6. [DOI: 10.1002/anie.201504782] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/03/2015] [Indexed: 11/11/2022]
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16
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Marchuk A, Celinski VR, Schmedt auf der Günne J, Schnick W. MH4P6N12(M=Mg, Ca): New Imidonitridophosphates with an Unprecedented Layered Network Structure Type. Chemistry 2015; 21:5836-42. [DOI: 10.1002/chem.201406240] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Indexed: 11/07/2022]
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17
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Pucher FJ, Frhr. von Schirnding C, Hummel F, Celinski VR, Schmedt auf der Günne J, Gerke B, Pöttgen R, Schnick W. Sn
6
[P
12
N
24
] – A Sodalite‐Type Nitridophosphate. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201403040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Florian J. Pucher
- Department of Chemistry, Chair in Inorganic Solid‐State Chemistry, University of Munich (LMU), Butenandtstr. 5–13 (D), 81377 Munich, Germany, http://www.cup.uni‐muenchen.de/ac/schnick
| | - Constantin Frhr. von Schirnding
- Department of Chemistry, Chair in Inorganic Solid‐State Chemistry, University of Munich (LMU), Butenandtstr. 5–13 (D), 81377 Munich, Germany, http://www.cup.uni‐muenchen.de/ac/schnick
| | - Franziska Hummel
- Department of Chemistry, Chair in Inorganic Solid‐State Chemistry, University of Munich (LMU), Butenandtstr. 5–13 (D), 81377 Munich, Germany, http://www.cup.uni‐muenchen.de/ac/schnick
| | - Vinicius R. Celinski
- Department of Chemistry, Chair in Inorganic Solid‐State Chemistry, University of Munich (LMU), Butenandtstr. 5–13 (D), 81377 Munich, Germany, http://www.cup.uni‐muenchen.de/ac/schnick
- Current address: Department of Chemistry and Biology, University of Siegen, Adolf‐Reichwein‐Str. 2, 57076 Siegen, Germany
| | - Jörn Schmedt auf der Günne
- Department of Chemistry, Chair in Inorganic Solid‐State Chemistry, University of Munich (LMU), Butenandtstr. 5–13 (D), 81377 Munich, Germany, http://www.cup.uni‐muenchen.de/ac/schnick
- Current address: Department of Chemistry and Biology, University of Siegen, Adolf‐Reichwein‐Str. 2, 57076 Siegen, Germany
| | - Birgit Gerke
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, 48149 Münster, Germany
| | - Rainer Pöttgen
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, 48149 Münster, Germany
| | - Wolfgang Schnick
- Department of Chemistry, Chair in Inorganic Solid‐State Chemistry, University of Munich (LMU), Butenandtstr. 5–13 (D), 81377 Munich, Germany, http://www.cup.uni‐muenchen.de/ac/schnick
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Mangstl M, Celinski VR, Johansson S, Weber J, An F, Schmedt auf der Günne J. Low temperature synthesis of ionic phosphates in dimethyl sulfoxide. Dalton Trans 2014; 43:10033-9. [DOI: 10.1039/c4dt00544a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new synthesis route for phosphates in an organic solvent at low temperatures is presented.
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Affiliation(s)
- Martin Mangstl
- Inorganic Materials Chemistry
- University of Siegen
- D-57068 Siegen, Germany
| | | | | | - Johannes Weber
- Inorganic Materials Chemistry
- University of Siegen
- D-57068 Siegen, Germany
| | - Feng An
- Department of Chemistry
- University of Munich
- D-81377 Munich, Germany
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Celinski VR, Weber J, Schmedt Auf der Günne J. C-REDOR curves of extended spin systems. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2013; 49-50:12-22. [PMID: 23141477 DOI: 10.1016/j.ssnmr.2012.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Revised: 09/28/2012] [Accepted: 10/01/2012] [Indexed: 06/01/2023]
Abstract
The convergence of simulated C-REDOR curves of (infinitely) large spin systems is investigated with respect to the number of spins considered in the calculations. Taking a sufficiently large number of spins (>20,000 spins) into account enables the simulation of converged C-REDOR curves over the entire time period and not only the initial regime. The calculations are based on an existing approximation within first order average Hamiltonian theory (AHT), which assumes the absence of homonuclear dipole-dipole interactions. The C-REDOR experiment generates an average Hamiltonian close to the idealized AHT behavior even for multiple spin systems including multiple homonuclear dipole-dipole interactions which is shown from numerically exact calculations of the spin dynamics. Experimentally it is shown that calculations accurately predict the full, experimental C-REDOR curves of the multi-spin systems (31)P-(19)F in apatite, (31)P-(1)H in potassium trimetaphosphimate and (1)H-(31)P in potassium dihydrogen phosphate. We also present (13)C-(1)H and (15)N-(1)H data for the organic compounds glycine, l-alanine and l-histidine hydrochloride monohydrate which require consideration of molecular motion. Furthermore, we investigated the current limits of the method from systematic errors and we suggest a simple way to calculate errors for homogeneous and heterogeneous samples from experimental data.
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Takeda K. Microcoils and microsamples in solid-state NMR. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2012; 47-48:1-9. [PMID: 23083521 DOI: 10.1016/j.ssnmr.2012.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 09/13/2012] [Accepted: 09/14/2012] [Indexed: 06/01/2023]
Abstract
Recent reports on microcoils are reviewed. The first part of the review includes a discussion of how the geometries of the sample and coil affect the NMR signal intensity. In addition to derivation of the well-known result that the signal intensity increases as the coil size decreases, the prediction that dilution of a small sample with magnetically inert matter leads to better sensitivity if a tiny coil is not available is given. The second part of the review focuses on the issues specific to solid-state NMR. They include realization of magic-angle spinning (MAS) using a microcoil and harnessing of such strong pulses that are feasible only with a microcoil. Two strategies for microcoil MAS, the piggyback method and magic-angle coil spinning (MACS), are reviewed. In addition, MAS of flat, disk-shaped samples is discussed in the context of solid-state NMR of small-volume samples. Strong RF irradiation, which has been exploited in wide-line spectral excitation, multiple-quantum MAS (MQMAS), and dipolar decoupling experiments, has been accompanied by new challenges regarding the Bloch-Siegert effect, the minimum time resolution of the spectrometer, and the time scale of pulse transient effects. For a possible solution to the latter problem, recent reports on active compensation of pulse transients are described.
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Affiliation(s)
- Kazuyuki Takeda
- Division of Chemistry, Graduate School of Science, Kyoto University, 606-8502 Kyoto, Japan.
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