Effects of Microwave Gating on Nuclear Spin Echoes in Dynamic Nuclear Polarization

2021 ◽  
pp. 175-182
Author(s):  
David Guarin ◽  
Diego Carnevale ◽  
Mathieu Baudin ◽  
Philippe Pelupessy ◽  
Daniel Abergel ◽  
...  
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Spin ◽  
Nuclear Polarization ◽  
Spin Echoes

Chemically Induced Dynamic Nuclear Polarization During Irradiation of Phenol in the Presence of Amides

1975 ◽  
Vol 53 (16) ◽  
pp. 2459-2464
Author(s):  
Shiv P. Vaish ◽  
Holger E. Chen ◽  
Micha Tomkiewicz ◽  
Robert D. McAlpine ◽  
Michael Cocivera
Keyword(s):  
Carbonyl Group ◽  
Spin Polarization ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Spin ◽  
Nuclear Polarization ◽  
Radical Pair ◽  
Hydroxybenzoic Acid ◽  
Nuclear Spin Polarization ◽  
Ph Values ◽  
Chemically Induced

Irradiation of D2O solutions containing various phenols with aliphatic amides at pH values between 9 and 12 results in nuclear spin polarization which is observed as n.m.r. emission signals during irradiation. No polarization is observed for the phenols which include tyrosine, cresol, p-hydroxybenzoic acid, phenol, and others. For the amides which include acetamide, propionamide, N-methylacetamide, and N,N-dimethylacetamide, polarization was observed for only the protons on the carbon bonded to the carbonyl group. Because excited phenolate ions are known to eject electrons, it is proposed that the radical RĊ(O−)NR2 is formed by reaction of the amide with the hydrated electron. The polarization observed for the amides can be explained by reaction of RĊ(O−)NR2 with a benzosemiquinone radical via a radical pair.

scholarly journals Maximizing NMR signal per unit time by facilitating the e–e–n cross effect DNP rate

2018 ◽  
Vol 20 (43) ◽  
pp. 27646-27657 ◽  
Author(s):  
Alisa Leavesley ◽  
Sheetal Jain ◽  
Ilia Kamniker ◽  
Hui Zhang ◽  
Suchada Rajca ◽  
...  
Keyword(s):  
Spin Relaxation ◽  
Electron Spin ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Spin ◽  
Nuclear Polarization ◽  
Nuclear Spin Relaxation ◽  
Cross Effect ◽  
Spin Clusters

Dynamic nuclear polarization (DNP) efficiency is critically dependent on the properties of the radical, solvent, and solute, where electron spin clusters will shorten nuclear spin relaxation and enhance CE-DNP.

scholarly journals Dynamic Nuclear Polarization of Long-Lived Nuclear Spin States in Methyl Groups

2017 ◽  
Vol 8 (15) ◽  
pp. 3549-3555 ◽  
Author(s):  
Jean-Nicolas Dumez ◽  
Basile Vuichoud ◽  
Daniele Mammoli ◽  
Aurélien Bornet ◽  
Arthur C. Pinon ◽  
...  
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Spin ◽  
Nuclear Polarization ◽  
Methyl Groups ◽  
Spin States

scholarly journals Tracing Dynamic Nuclear Polarization Pathways Using Transition Metal - Nuclear Spin Rulers

2019 ◽  
Author(s):  
Sheetal Kumar Jain ◽  
Chung-Jui Yu ◽  
Blake Wilson ◽  
Tarnuma Tabassum ◽  
Danna E. Freedman ◽  
...  
Keyword(s):  
Transition Metal ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Spin ◽  
Pulse Shaping ◽  
Nuclear Polarization ◽  
Spin Diffusion ◽  
Protein Structures ◽  
Organic Radical ◽  
Waveform Generator ◽  
Low Sensitivity

<p><a></a>The ubiquitous technique of nuclear magnetic resonance (NMR) spectroscopy suffers from relatively low sensitivity due to the low polarization of nuclei. For decades, the technique of dynamic nuclear polarization (DNP) has been harnessed to increase the sensitivity of NMR, enabling detection of low abundance nuclei such as <sup>17</sup>O and elucidation of protein structures. Yet, the catalogue of DNP agents today is limited to organic radical species, accompanied by a handful of metal ions (Cr<sup>3+</sup>, Mn<sup>2+</sup>, and Gd<sup>3+</sup>). This study significantly expands the scope and catalogue of DNP with the first demonstration of amplification of nuclear spin polarization at a set distance from a transition metal center (V<sup>4+</sup>) that has g-values significantly varied from 2 and anisotropic EPR line that is more than 3GHz broad.We showed that <sup>1</sup>H NMR signal enhancements of up to 33 can be achieved at 6.9T field and 4K temperature using a home-built DNP instrumentation that allows microwave irradiation over a frequency range of more than 10 GHz with pulse shaping capabilities by arbitrary waveform generator. A series of systematically designed vanadyl complexes, with V<sup>4+</sup>-<sup>1</sup>H distances in range 4.0 Å to 13.6 Å, was used to trace the polarization pathway of DNP and determine the size of the spin-diffusion barrier.<br></p>

scholarly journals Enhancement of nuclear spin coherence times by driving dynamic nuclear polarization at defect centers in solids

2019 ◽  
Vol 99 (20) ◽  
Author(s):  
Girish Sharma ◽  
Torsten Gaebel ◽  
Ewa Rej ◽  
David J. Reilly ◽  
Sophia E. Economou ◽  
...  
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Spin ◽  
Nuclear Polarization ◽  
Spin Coherence ◽  
Driving Dynamic ◽  
Defect Centers

Dynamic nuclear polarization and Hanle effect in (In,Ga)As/GaAs quantum dots. Role of nuclear spin fluctuations

2013 ◽  
Author(s):  
I. Ya. Gerlovin ◽  
R. V. Cherbunin ◽  
I. V. Ignatiev ◽  
M. S. Kuznetsova ◽  
S. Yu. Verbin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Spin ◽  
Nuclear Polarization ◽  
Spin Fluctuations ◽  
Hanle Effect

scholarly journals Tracing Dynamic Nuclear Polarization Pathways Using Transition Metal - Nuclear Spin Rulers

2019 ◽  
Author(s):  
Sheetal Kumar Jain ◽  
Chung-Jui Yu ◽  
Blake Wilson ◽  
Tarnuma Tabassum ◽  
Danna E. Freedman ◽  
...  
Keyword(s):  
Transition Metal ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Spin ◽  
Pulse Shaping ◽  
Nuclear Polarization ◽  
Spin Diffusion ◽  
Protein Structures ◽  
Organic Radical ◽  
Waveform Generator ◽  
Low Sensitivity

<p><a></a>The ubiquitous technique of nuclear magnetic resonance (NMR) spectroscopy suffers from relatively low sensitivity due to the low polarization of nuclei. For decades, the technique of dynamic nuclear polarization (DNP) has been harnessed to increase the sensitivity of NMR, enabling detection of low abundance nuclei such as <sup>17</sup>O and elucidation of protein structures. Yet, the catalogue of DNP agents today is limited to organic radical species, accompanied by a handful of metal ions (Cr<sup>3+</sup>, Mn<sup>2+</sup>, and Gd<sup>3+</sup>). This study significantly expands the scope and catalogue of DNP with the first demonstration of amplification of nuclear spin polarization at a set distance from a transition metal center (V<sup>4+</sup>) that has g-values significantly varied from 2 and anisotropic EPR line that is more than 3GHz broad.We showed that <sup>1</sup>H NMR signal enhancements of up to 33 can be achieved at 6.9T field and 4K temperature using a home-built DNP instrumentation that allows microwave irradiation over a frequency range of more than 10 GHz with pulse shaping capabilities by arbitrary waveform generator. A series of systematically designed vanadyl complexes, with V<sup>4+</sup>-<sup>1</sup>H distances in range 4.0 Å to 13.6 Å, was used to trace the polarization pathway of DNP and determine the size of the spin-diffusion barrier.<br></p>

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