Dynamic nuclear polarization assisted spin diffusion for the solid effect case

2011 ◽  
Vol 134 (7) ◽  
pp. 074509 ◽  
Author(s):  
Yonatan Hovav ◽  
Akiva Feintuch ◽  
Shimon Vega
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Spin Diffusion ◽  
Solid Effect

scholarly journals Dynamic nuclear polarization and ESR hole burning in As doped silicon

2020 ◽  
Vol 22 (18) ◽  
pp. 10227-10237 ◽  
Author(s):  
J. Järvinen ◽  
D. Zvezdov ◽  
J. Ahokas ◽  
S. Sheludiakov ◽  
L. Lehtonen ◽  
...  
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Spin Diffusion ◽  
Hole Burning ◽  
Doped Silicon ◽  
Solid Effect ◽  
Decoupling Effect

Electron decoupling effect on Overhauser DNP, solid effect DNP and spin diffusion are measured with EPR in As doped silicon.

scholarly journals Solid effect dynamic nuclear polarization and polarization pathways

2012 ◽  
Vol 136 (1) ◽  
pp. 015101 ◽  
Author(s):  
Albert A. Smith ◽  
Björn Corzilius ◽  
Alexander B. Barnes ◽  
Thorsten Maly ◽  
Robert G. Griffin
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Solid Effect

Enhanced dynamic nuclear polarization by the integrated solid effect

1988 ◽  
Vol 134 (2) ◽  
pp. 134-136 ◽  
Author(s):  
A. Henstra ◽  
P. Dirksen ◽  
W.Th. Wenckebach
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Solid Effect

scholarly journals Three-spin solid effect and the spin diffusion barrier in amorphous solids

2019 ◽  
Vol 5 (7) ◽  
pp. eaax2743 ◽  
Author(s):  
Kong Ooi Tan ◽  
Michael Mardini ◽  
Chen Yang ◽  
Jan Henrik Ardenkjær-Larsen ◽  
Robert G. Griffin
Keyword(s):  
Diffusion Barrier ◽  
Nuclear Polarization ◽  
Spin Diffusion ◽  
Amorphous Solids ◽  
Second Step ◽  
Intimate Contact ◽  
Glycerol Water ◽  
Water Matrix ◽  
Solid Effect ◽  
Trityl Radical

Dynamic nuclear polarization (DNP) has evolved as the method of choice to enhance NMR signal intensities and to address a variety of otherwise inaccessible chemical, biological and physical questions. Despite its success, there is no detailed understanding of how the large electron polarization is transferred to the surrounding nuclei or where these nuclei are located relative to the polarizing agent. To address these questions we perform an analysis of the three-spin solid effect, and show that it is exquisitely sensitive to the electron-nuclear distances. We exploit this feature and determine that the size of the spin diffusion barrier surrounding the trityl radical in a glassy glycerol–water matrix is <6 Å, and that the protons involved in the initial transfer step are on the trityl molecule. 1H ENDOR experiments indicate that polarization is then transferred in a second step to glycerol molecules in intimate contact with the trityl.

Inhomogeneous dynamic nuclear polarization of protons in a lamella-forming diblock copolymer investigated by a small-angle neutron scattering method

2011 ◽  
Vol 44 (3) ◽  
pp. 503-513 ◽  
Author(s):  
Yohei Noda ◽  
Takayuki Kumada ◽  
Takeji Hashimoto ◽  
Satoshi Koizumi
Keyword(s):  
Neutron Scattering ◽  
Diblock Copolymer ◽  
Dynamic Nuclear Polarization ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Nuclear Polarization ◽  
Spin Diffusion ◽  
Second Order ◽  
Third Order ◽  
Proton Polarization

By combining two methods of selective doping of paramagnetic species into a microdomain and small-angle neutron scattering (SANS), thespatially inhomogeneous proton polarizationcreated by dynamic nuclear polarization (DNP) has been precisely evaluated. A lamella-forming diblock copolymer composed of polystyrene (PS) and polyisoprene (PI) block chains (PS-b-PI) was employed, the SANS profile of which clearly shows scattering peaks up to the third order due to interlamellar interference. As a source of electron spin for DNP, 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) was doped into one or other of the microdomains; samples with PS or PI microdomains selectively doped with TEMPO are designated PS.-b-PI and PS-b-PI., respectively. The SANS intensity at the first- and third-order peaks is well reproduced by assuming that the proton polarization is homogeneous throughout the sample, but that at the second-order peak cannot be explained by this assumption. This anomaly regarding the second-order peak was successfully explained by a model postulating that proton polarization in a doped microdomain decreases with increasing distance from the interface with a neighbouring doped microdomain. The decrease in proton polarization at the centre of a doped microdomain was estimated to be 0.07 (2) for PS-b-PI.and 0.05 (1) for PS.-b-PI, relative to constant proton polarization in a doped microdomain. The inhomogeneous proton polarization results from two competing dynamic processes,i.e.spin diffusion from doped to undoped microdomains, and spin lattice relaxation occurring on the pathway of proton spin diffusion.

Static 1H dynamic nuclear polarization with the biradical TOTAPOL: a transition between the solid effect and the cross effect

2014 ◽  
Vol 16 (14) ◽  
pp. 6687-6699 ◽  
Author(s):  
Daphna Shimon ◽  
Akiva Feintuch ◽  
Daniella Goldfarb ◽  
Shimon Vega
Keyword(s):  
High Temperatures ◽  
Dynamic Nuclear Polarization ◽  
Low Temperatures ◽  
Nuclear Polarization ◽  
Cross Effect ◽  
Solid Effect ◽  
The Cross

Static 1H-DNP with TOTAPOL: the solid effect (SE) dominant at low temperatures; the cross effect (CE) dominant at high temperatures; and DNP-buildup: Tbu(SE) < Tbu(CE).

Bis-Gadolinium Complexes for Solid Effect and Cross Effect Dynamic Nuclear Polarization

2017 ◽  
Vol 129 (15) ◽  
pp. 4359-4363
Author(s):  
Monu Kaushik ◽  
Mian Qi ◽  
Adelheid Godt ◽  
Björn Corzilius
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Cross Effect ◽  
Gadolinium Complexes ◽  
Solid 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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