Pub Date : 2021-04-01DOI: 10.1016/j.ssnmr.2020.101709
Takahiro Iijima , Shinobu Ohki , Masataka Tansho
Separated pure-quadrupole (PQ) and -shift (PS) spectra of 2H nuclear magnetic resonance (NMR) of paramagnetic solids are obtained and correlated by simple pulse sequences that can acquire the full magnetization under ideal conditions. Two-dimensional NMR signals obtained using an asymmetric π-pulse-inserted quadrupole-echo (APIQE) sequence yielded separated spectra through the skew operation of an affine transform (AT) before a Fourier transform. Modified APIQE sequences that acquire whole echo signals were fabricated, and separated PQ and PS spectra were obtained by applying a combination of AT, such as rotation and skew operations, to the signal data. These methods were demonstrated for diamagnetic Zn(CD3CO2)2⋅2H2O and paramagnetic Nd(CD3CO2)3⋅1.5H2O. Further, the dynamics of the D2O molecule and [Co(D2O)6]2+ ion in paramagnetic CoSiF6⋅6D2O was analyzed based on the temperature dependence of the separated spectra.
{"title":"Separated quadrupole and shift interactions of 2H NMR spectra in paramagnetic solids by asymmetric pulse sequences","authors":"Takahiro Iijima , Shinobu Ohki , Masataka Tansho","doi":"10.1016/j.ssnmr.2020.101709","DOIUrl":"10.1016/j.ssnmr.2020.101709","url":null,"abstract":"<div><p>Separated pure-quadrupole (PQ) and -shift (PS) spectra of <sup>2</sup><span>H nuclear magnetic resonance (NMR) of paramagnetic solids are obtained and correlated by simple pulse sequences that can acquire the full magnetization under ideal conditions. Two-dimensional NMR signals obtained using an asymmetric </span><em>π</em><span>-pulse-inserted quadrupole-echo (APIQE) sequence yielded separated spectra through the skew operation of an affine transform (AT) before a Fourier transform<span>. Modified APIQE sequences that acquire whole echo signals were fabricated, and separated PQ and PS spectra were obtained by applying a combination of AT, such as rotation and skew operations, to the signal data. These methods were demonstrated for diamagnetic Zn(CD</span></span><sub>3</sub>CO<sub>2</sub>)<sub>2</sub>⋅2H<sub>2</sub>O and paramagnetic Nd(CD<sub>3</sub>CO<sub>2</sub>)<sub>3</sub>⋅1.5H<sub>2</sub>O. Further, the dynamics of the D<sub>2</sub>O molecule and [Co(D<sub>2</sub>O)<sub>6</sub>]<sup>2+</sup><span> ion in paramagnetic CoSiF</span><sub>6</sub>⋅6D<sub>2</sub>O was analyzed based on the temperature dependence of the separated spectra.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101709","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38864017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-01DOI: 10.1016/j.ssnmr.2020.101711
Yi Ji , Lixin Liang , Xinhe Bao , Guangjin Hou
With the recent advances in NMR hardware and probe design technology, magic-angle spinning (MAS) rates over 100 kHz are accessible now, even on commercial solid NMR probes. Under such fast MAS conditions, excellent spectral resolution has been achieved by efficient suppression of anisotropic interactions, which also opens an avenue to the proton-detected NMR experiments in solids. Numerous methods have been developed to take full advantage of fast MAS during the last decades. Among them, dipolar recoupling techniques under fast MAS play vital roles in the determination of the molecular structure and dynamics, and are also key elements in multi-dimensional correlation NMR experiments. Herein, we review the dipolar recoupling techniques, especially those developed in the past two decades for fast-to-ultrafast MAS conditions. A major focus for our discussion is the ratio of RF field strength (in frequency) to MAS frequency, /, in different pulse sequences, which determines whether these dipolar recoupling techniques are suitable for NMR experiments under fast MAS conditions. Systematic comparisons are made among both heteronuclear and homonuclear dipolar recoupling schemes. In addition, the schemes developed specially for proton-detection NMR experiments under ultrafast MAS conditions are highlighted as well.
{"title":"Recent progress in dipolar recoupling techniques under fast MAS in solid-state NMR spectroscopy","authors":"Yi Ji , Lixin Liang , Xinhe Bao , Guangjin Hou","doi":"10.1016/j.ssnmr.2020.101711","DOIUrl":"10.1016/j.ssnmr.2020.101711","url":null,"abstract":"<div><p><span><span>With the recent advances in NMR hardware and probe design technology, magic-angle spinning (MAS) rates over 100 kHz are accessible now, even on commercial solid NMR probes. Under such fast MAS conditions, excellent spectral resolution has been achieved by efficient suppression of anisotropic interactions, which also opens an avenue to the proton-detected NMR experiments in solids. Numerous methods have been developed to take full advantage of fast MAS during the last decades. Among them, dipolar recoupling<span> techniques under fast MAS play vital roles in the determination of the molecular structure and dynamics, and are also key elements in multi-dimensional correlation NMR experiments. Herein, we review the dipolar recoupling techniques, especially those developed in the past two decades for fast-to-ultrafast MAS conditions. A major focus for our discussion is the ratio of RF field </span></span>strength (in frequency) to MAS frequency, </span><span><math><mrow><msub><mi>ν</mi><mn>1</mn></msub></mrow></math></span>/<span><math><mrow><msub><mi>ν</mi><mi>r</mi></msub></mrow></math></span>, in different pulse sequences, which determines whether these dipolar recoupling techniques are suitable for NMR experiments under fast MAS conditions. Systematic comparisons are made among both heteronuclear and homonuclear dipolar recoupling schemes. In addition, the schemes developed specially for proton-detection NMR experiments under ultrafast MAS conditions are highlighted as well.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101711","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38872026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-01DOI: 10.1016/j.ssnmr.2020.101710
Liliya Vugmeyster
Slow timescale dynamics in proteins are essential for a variety of biological functions spanning ligand binding, enzymatic catalysis, protein folding and misfolding regulations, as well as protein–protein and protein–nucleic acid interactions. In this review, we focus on the experimental and theoretical developments of 2H static NMR methods applicable for studies of microsecond to millisecond motional modes in proteins, particularly rotating frame relaxation dispersion (R1ρ), quadrupolar Carr–Purcell–Meiboom–Gill (QCPMG) relaxation dispersion, and quadrupolar chemical exchange saturation transfer NMR experiments (Q-CEST). With applications chosen from amyloid-β fibrils, we show the complementarity of these approaches for elucidating the complexities of conformational ensembles in disordered domains in the non-crystalline solid state, with the employment of selective deuterium labels. Combined with recent advances in relaxation dispersion backbone measurements for 15N/13C/1H nuclei, these techniques provide powerful tools for studies of biologically relevant timescale dynamics in disordered domains in the solid state.
{"title":"Recent developments in deuterium solid-state NMR for the detection of slow motions in proteins","authors":"Liliya Vugmeyster","doi":"10.1016/j.ssnmr.2020.101710","DOIUrl":"10.1016/j.ssnmr.2020.101710","url":null,"abstract":"<div><p><span><span>Slow timescale dynamics in proteins are essential for a variety of biological functions spanning ligand binding, enzymatic catalysis, </span>protein folding and misfolding regulations, as well as protein–protein and protein–nucleic acid interactions. In this review, we focus on the experimental and theoretical developments of </span><sup>2</sup>H static NMR methods applicable for studies of microsecond to millisecond motional modes in proteins, particularly rotating frame relaxation dispersion (<em>R</em><sub>1ρ</sub><span>), quadrupolar Carr–Purcell–Meiboom–Gill (QCPMG) relaxation dispersion, and quadrupolar chemical exchange saturation transfer<span> NMR experiments (Q-CEST). With applications chosen from amyloid-β fibrils, we show the complementarity of these approaches for elucidating the complexities of conformational ensembles in disordered domains in the non-crystalline solid state, with the employment of selective deuterium labels. Combined with recent advances in relaxation dispersion backbone measurements for </span></span><sup>15</sup>N/<sup>13</sup>C/<sup>1</sup>H nuclei, these techniques provide powerful tools for studies of biologically relevant timescale dynamics in disordered domains in the solid state.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101710","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38826956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-01DOI: 10.1016/j.ssnmr.2020.101712
Frédéric A. Perras, Alexander L. Paterson, Takeshi Kobayashi
γ-encoded recoupling sequences are known to produce strong amplitude modulations that lead to sharp doublets when Fourier transformed. These doublets depend very little on the recoupled tensor asymmetry and thus enable for the straightforward determination of dynamic order parameters. It can, however, be difficult to measure small anisotropies, or small order parameters, using such sequences; the resonances from the doublet may overlap with each other, or with the zero-frequency glitch. This limitation has prevented the widespread use of 1H chemical shift anisotropy (CSA) for the measurement of dynamics, particularly for CH protons which typically have CSAs of only a few ppm when immobile. Here, we introduce a simple modification to the traditional 1H CSA and proton-detected local field pulse sequences that enables the acquisition of a hypercomplex dataset and the removal of the uncorrelated magnetization that results in the zero-frequency glitch. These new sequences then yield a frequency shift in the indirect dimension, rather than a splitting, which is easily identifiable even in cases of weak interactions.
{"title":"Phase-sensitive γ-encoded recoupling of heteronuclear dipolar interactions and 1H chemical shift anisotropy","authors":"Frédéric A. Perras, Alexander L. Paterson, Takeshi Kobayashi","doi":"10.1016/j.ssnmr.2020.101712","DOIUrl":"10.1016/j.ssnmr.2020.101712","url":null,"abstract":"<div><p>γ-encoded recoupling sequences are known to produce strong amplitude modulations that lead to sharp doublets when Fourier transformed. These doublets depend very little on the recoupled tensor asymmetry and thus enable for the straightforward determination of dynamic order parameters. It can, however, be difficult to measure small anisotropies, or small order parameters, using such sequences; the resonances from the doublet may overlap with each other, or with the zero-frequency glitch. This limitation has prevented the widespread use of <sup>1</sup><span>H chemical shift anisotropy (CSA) for the measurement of dynamics, particularly for CH protons which typically have CSAs of only a few ppm when immobile. Here, we introduce a simple modification to the traditional </span><sup>1</sup>H CSA and proton-detected local field pulse sequences that enables the acquisition of a hypercomplex dataset and the removal of the uncorrelated magnetization that results in the zero-frequency glitch. These new sequences then yield a frequency shift in the indirect dimension, rather than a splitting, which is easily identifiable even in cases of weak interactions.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101712","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38826957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-01DOI: 10.1016/j.ssnmr.2020.101701
Joel Lapin, Emmanuel O. Awosanya, Richard J.A. Esteves, Alexander A. Nevzorov
The benefits of triple-resonance experiments for structure determination of macroscopically oriented membrane proteins by solid-state NMR are discussed. While double-resonance 1H/15N experiments are effective for structure elucidation of alpha-helical domains, extension of the method of oriented samples to more complex topologies and assessing side-chain conformations necessitates further development of triple-resonance (1H/13C/15N) NMR pulse sequences. Incorporating additional spectroscopic dimensions involving 13C spin-bearing nuclei, however, introduces essential complications arising from the wide frequency range of the 1H-13C dipolar couplings and 13C CSA (>20 kHz), and the presence of the 13C-13C homonuclear dipole-dipole interactions. The recently reported ROULETTE–CAHA pulse sequence, in combination with the selective z-filtering, can be used to evolve the structurally informative 1H-13C dipolar coupling arising from the aliphatic carbons while suppressing the signals from the carbonyl and methyl regions. Proton-mediated magnetization transfer under mismatched Hartman-Hahn conditions (MMHH) can be used to correlate 13C and 15N nuclei in such triple-resonance experiments for the subsequent 15N detection. The recently developed pulse sequences are illustrated for n-acetyl Leucine (NAL) single crystal and doubly labeled Pf1 coat protein reconstituted in magnetically aligned bicelles. An interesting observation is that in the case of 15N-labeled NAL measured at 13C natural abundance, the triple (1H/13C/15N) MMHH scheme predominantly gives rise to long-range intermolecular magnetization transfers from 13C to 15N spins; whereas direct Hartmann-Hahn 13C/15N transfer is entirely intramolecular. The presented developments advance NMR of oriented samples for structure determination of membrane proteins and liquid crystals.
{"title":"1H/13C/15N triple-resonance experiments for structure determinaton of membrane proteins by oriented-sample NMR","authors":"Joel Lapin, Emmanuel O. Awosanya, Richard J.A. Esteves, Alexander A. Nevzorov","doi":"10.1016/j.ssnmr.2020.101701","DOIUrl":"10.1016/j.ssnmr.2020.101701","url":null,"abstract":"<div><p>The benefits of triple-resonance experiments for structure determination of macroscopically oriented membrane proteins by solid-state NMR are discussed. While double-resonance <sup>1</sup>H/<sup>15</sup><span>N experiments are effective for structure elucidation of alpha-helical domains, extension of the method of oriented samples to more complex topologies and assessing side-chain conformations necessitates further development of triple-resonance (</span><sup>1</sup>H/<sup>13</sup>C/<sup>15</sup>N) NMR pulse sequences. Incorporating additional spectroscopic dimensions involving <sup>13</sup>C spin-bearing nuclei, however, introduces essential complications arising from the wide frequency range of the <sup>1</sup>H-<sup>13</sup><span>C dipolar couplings and </span><sup>13</sup><span>C CSA (>20 kHz), and the presence of the </span><sup>13</sup>C-<sup>13</sup>C homonuclear dipole-dipole interactions. The recently reported ROULETTE–CAHA pulse sequence, in combination with the selective z-filtering, can be used to evolve the structurally informative <sup>1</sup>H-<sup>13</sup><span>C dipolar coupling arising from the aliphatic carbons while suppressing the signals from the carbonyl and methyl regions. Proton-mediated magnetization transfer under mismatched Hartman-Hahn conditions (MMHH) can be used to correlate </span><sup>13</sup>C and <sup>15</sup>N nuclei in such triple-resonance experiments for the subsequent <sup>15</sup><span>N detection. The recently developed pulse sequences are illustrated for n-acetyl Leucine<span> (NAL) single crystal and doubly labeled Pf1 coat protein reconstituted in magnetically aligned bicelles. An interesting observation is that in the case of </span></span><sup>15</sup>N-labeled NAL measured at <sup>13</sup>C natural abundance, the triple (<sup>1</sup>H/<sup>13</sup>C/<sup>15</sup>N) MMHH scheme predominantly gives rise to long-range intermolecular magnetization transfers from <sup>13</sup>C to <sup>15</sup>N spins; whereas direct Hartmann-Hahn <sup>13</sup>C/<sup>15</sup>N transfer is entirely intramolecular. The presented developments advance NMR of oriented samples for structure determination of membrane proteins and liquid crystals.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101701","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38661792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1039/9781839164965-00151
Ryan E. Mewis
{"title":"Hyperpolarisation techniques","authors":"Ryan E. Mewis","doi":"10.1039/9781839164965-00151","DOIUrl":"https://doi.org/10.1039/9781839164965-00151","url":null,"abstract":"","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86793160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.1016/j.ssnmr.2020.101698
Qian Wang, Ulla Gro Nielsen
Environmental science is an interdisciplinary field, which integrates chemical, physical, and biological sciences to study environmental problems and human impact on the environment. This article highlights the use of solid-state NMR spectroscopy (SSNMR) in studies of environmental processes and remediation with examples from both laboratory studies and samples collected in the field. The contemporary topics presented include soil chemistry, environmental remediation (e.g., heavy metals and radionuclides removal, carbon dioxide mineralization), and phosphorus recovery. SSNMR is a powerful technique, which provides atomic-level information about speciation in complex environmental samples as well as the interactions between pollutants and minerals/organic matter on different environmental interfaces. The challenges in the application of SSNMR in environmental science (e.g., measurement of paramagnetic nuclei and low-gamma nuclei) are also discussed, and perspectives are provided for the future research efforts.
{"title":"Applications of solid-state NMR spectroscopy in environmental science","authors":"Qian Wang, Ulla Gro Nielsen","doi":"10.1016/j.ssnmr.2020.101698","DOIUrl":"10.1016/j.ssnmr.2020.101698","url":null,"abstract":"<div><p><span><span>Environmental science is an interdisciplinary field, which integrates chemical, physical, and biological sciences to study environmental problems and human impact on the environment. This article highlights the use of solid-state NMR spectroscopy (SSNMR) in studies of environmental processes and remediation with examples from both laboratory studies and samples collected in the field. The contemporary topics presented include soil </span>chemistry, environmental remediation (e.g., heavy metals and </span>radionuclides removal, carbon dioxide mineralization), and phosphorus recovery. SSNMR is a powerful technique, which provides atomic-level information about speciation in complex environmental samples as well as the interactions between pollutants and minerals/organic matter on different environmental interfaces. The challenges in the application of SSNMR in environmental science (e.g., measurement of paramagnetic nuclei and low-gamma nuclei) are also discussed, and perspectives are provided for the future research efforts.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101698","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38558086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.1016/j.ssnmr.2020.101700
A. Samila , I. Safronov , O. Hotra
The paper describes development of the detailed structure and circuit diagrams of the continuous wave NQR temperature sensor with increased conversion linearity. It is experimentally established that at amplitude modulation of 40% and change of input voltage in the range of 20–1000 mV, the circuit of a symmetric marginal oscillator with a linear active demodulator provides better linearity of transfer characteristic than the circuits of asymmetric marginal oscillators with JFET or diode detectors. As a thermometric substance of the proposed NQR sensor, copper oxide Cu2O was used, which is characterized by a strong temperature dependence of the resonance frequency of 63Cu NQR. In contrast to 35Cl NQR in KClO3, for cuprous oxide the temperature dependence of 63Сu NQR frequency in the frequency range 26.621–25.658 MHz is linear in the temperature range 100–390 K. It is experimentally confirmed that the use of a low mass sample (less than 200 mg) as a thermometric substance of the proposed NQR sensor is quite sufficient for successfully observation of the resonance line at the SNR equal to 9.1 dB.
{"title":"Structural and functional synthesis of the continuous wave NQR temperature sensor with increased conversion linearity","authors":"A. Samila , I. Safronov , O. Hotra","doi":"10.1016/j.ssnmr.2020.101700","DOIUrl":"10.1016/j.ssnmr.2020.101700","url":null,"abstract":"<div><p><span><span><span>The paper describes development of the detailed structure and circuit diagrams of the continuous wave NQR </span>temperature sensor with increased conversion linearity. It is experimentally established that at amplitude modulation of 40% and change of input voltage in the range of 20–1000 mV, the circuit of a symmetric marginal </span>oscillator<span> with a linear active demodulator provides better linearity of transfer characteristic than the circuits of asymmetric marginal oscillators with JFET<span> or diode detectors. As a thermometric substance of the proposed NQR sensor, copper oxide Cu</span></span></span><sub>2</sub>O was used, which is characterized by a strong temperature dependence of the resonance frequency of <sup>63</sup>Cu NQR. In contrast to <sup>35</sup>Cl NQR in KClO<sub>3</sub><span>, for cuprous oxide the temperature dependence of </span><sup>63</sup><span>Сu NQR frequency in the frequency range 26.621–25.658 MHz is linear in the temperature range 100–390 K. It is experimentally confirmed that the use of a low mass sample (less than 200 mg) as a thermometric substance of the proposed NQR sensor is quite sufficient for successfully observation of the resonance line at the SNR equal to 9.1 dB.</span></p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101700","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38620538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.1016/j.ssnmr.2020.101697
Michael W. Malone , Michelle A. Espy , Sun He , Michael T. Janicke , Robert F. Williams
We report the 1H dispersion curve between 0 and 5 MHz for the synthetic opioid fentanyl citrate (C28H36N2O8). The structures in the curve can be used to estimate the 14N nuclear quadrupole resonance (NQR) frequencies of the material. Density functional theory predictions of the NQR parameters of several fentanyl citrate compounds are also reported. The predictions for the aniline nitrogen are consistent with structures in the observed data. To help interpret the fentanyl citrate results the dispersion curve for the explosive ammonium nitrate is also presented.
{"title":"The 1H T1 dispersion curve of fentanyl citrate to identify NQR parameters","authors":"Michael W. Malone , Michelle A. Espy , Sun He , Michael T. Janicke , Robert F. Williams","doi":"10.1016/j.ssnmr.2020.101697","DOIUrl":"10.1016/j.ssnmr.2020.101697","url":null,"abstract":"<div><p>We report the <sup>1</sup>H <span><math><mrow><msub><mi>T</mi><mn>1</mn></msub></mrow></math></span> dispersion curve between 0 and 5 MHz for the synthetic opioid fentanyl citrate (C<sub>28</sub>H<sub>36</sub>N<sub>2</sub>O<sub>8</sub>). The structures in the curve can be used to estimate the <sup>14</sup><span>N nuclear quadrupole resonance (NQR) frequencies of the material. Density functional theory predictions of the NQR parameters of several fentanyl citrate compounds are also reported. The predictions for the aniline nitrogen are consistent with structures in the observed </span><span><math><mrow><msub><mi>T</mi><mn>1</mn></msub></mrow></math></span> data. To help interpret the fentanyl citrate results the <span><math><mrow><msub><mi>T</mi><mn>1</mn></msub></mrow></math></span><span> dispersion curve for the explosive ammonium nitrate is also presented.</span></p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101697","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38504569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.1016/j.ssnmr.2020.101699
Maxime Yon, Franck Fayon, Dominique Massiot, Vincent Sarou-Kanian
We present an algorithm suitable for automatically correcting rolling baseline coming from time-domain truncation induced by the dead time in pulse-acquire one-dimensional MAS NMR spectra. It relies on an iterative estimation of the baseline restricted in the time-domain by the dead time duration combined with a histogram filter allowing adaptive selection of the baseline points. This method does not make any assumption regarding the NMR resonances line shapes or widths and does not modify the acquired free induction decay points. This makes it suitable for accurate deconvolution and quantification of single-pulse MAS NMR spectra. The baseline correction accuracy is evaluated on synthetic solid-state spectra of 19F, 71Ga, and 23Na by comparing the fitted baseline to the theoretical one. The versatility of the algorithm is also exemplified on three additional solid-state spectra of 23Na and 71Ga. The algorithm is made available to the community through a user-friendly standalone Matlab® application.
{"title":"Iterative baseline correction algorithm for dead time truncated one-dimensional solid-state MAS NMR spectra","authors":"Maxime Yon, Franck Fayon, Dominique Massiot, Vincent Sarou-Kanian","doi":"10.1016/j.ssnmr.2020.101699","DOIUrl":"10.1016/j.ssnmr.2020.101699","url":null,"abstract":"<div><p><span><span>We present an algorithm suitable for automatically correcting rolling baseline coming from time-domain truncation induced by the dead time in pulse-acquire one-dimensional MAS </span>NMR spectra<span>. It relies on an iterative estimation of the baseline restricted in the time-domain by the dead time duration combined with a histogram filter allowing adaptive selection of the baseline points. This method does not make any assumption regarding the NMR resonances line shapes or widths and does not modify the acquired free induction decay points. This makes it suitable for accurate deconvolution and quantification of single-pulse MAS NMR spectra. The baseline correction accuracy is evaluated on synthetic solid-state spectra of </span></span><sup>19</sup>F, <sup>71</sup>Ga, and <sup>23</sup>Na by comparing the fitted baseline to the theoretical one. The versatility of the algorithm is also exemplified on three additional solid-state spectra of <sup>23</sup>Na and <sup>71</sup>Ga. The algorithm is made available to the community through a user-friendly standalone Matlab® application.</p></div>","PeriodicalId":21937,"journal":{"name":"Solid state nuclear magnetic resonance","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ssnmr.2020.101699","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38601561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}