The spin diffusion in the dynamic polarization by solid effect

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.

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Dynamic polarization of protons in radiation-damaged polyethylene by the solid effect

Physics Letters ◽

10.1016/0031-9163(66)90259-9 ◽

1966 ◽

Vol 23 (1) ◽

pp. 63-64 ◽

Cited By ~ 5

Author(s):

D.A. Hill ◽

B.A. Hasher ◽

C.F. Hwang

Keyword(s):

Dynamic Polarization ◽

Solid Effect

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Room-temperature hyperpolarization of polycrystalline samples with optically polarized triplet electrons: pentacene or nitrogen-vacancy center in diamond?

Magnetic Resonance ◽

10.5194/mr-2-33-2021 ◽

2021 ◽

Vol 2 (1) ◽

pp. 33-48

Author(s):

Koichiro Miyanishi ◽

Takuya F. Segawa ◽

Kazuyuki Takeda ◽

Izuru Ohki ◽

Shinobu Onoda ◽

...

Keyword(s):

Benzoic Acid ◽

Room Temperature ◽

Spin Diffusion ◽

Polarization Transfer ◽

Nitrogen Vacancy ◽

Nitrogen Vacancy Center ◽

Direct Polarization ◽

Solid Effect ◽

Acid Sample ◽

Vacancy Center

Abstract. We demonstrate room-temperature 13C hyperpolarization by dynamic nuclear polarization (DNP) using optically polarized triplet electron spins in two polycrystalline systems: pentacene-doped [carboxyl-13C] benzoic acid and microdiamonds containing nitrogen-vacancy (NV−) centers. For both samples, the integrated solid effect (ISE) is used to polarize the 13C spin system in magnetic fields of 350–400 mT. In the benzoic acid sample, the 13C spin polarization is enhanced by up to 0.12 % through direct electron-to-13C polarization transfer without performing dynamic 1H polarization followed by 1H−13C cross-polarization. In addition, the ISE has been successfully applied to polarize naturally abundant 13C spins in a microdiamond sample to 0.01 %. To characterize the buildup of the 13C polarization, we discuss the efficiencies of direct polarization transfer between the electron and 13C spins as well as that of 13C−13C spin diffusion, examining various parameters which are beneficial or detrimental for successful bulk dynamic 13C polarization.

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A contribution to the study of dynamic polarization by solid effect

Il Nuovo Cimento B ◽

10.1007/bf02710417 ◽

1970 ◽

Vol 68 (2) ◽

pp. 253-281 ◽

Cited By ~ 1

Author(s):

G. Baldacchini ◽

V. Montelatici

Keyword(s):

Dynamic Polarization ◽

Solid Effect

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Room temperature hyperpolarization of polycrystalline samples with optically polarized triplet electrons: Pentacene or Nitrogen-Vacancy center in diamond?

10.5194/mr-2020-36 ◽

2020 ◽

Author(s):

Koichiro Miyanishi ◽

Takuya F. Segawa ◽

Kazuyuki Takeda ◽

Izuru Ohki ◽

Shinobu Onoda ◽

...

Keyword(s):

Benzoic Acid ◽

Room Temperature ◽

Spin Diffusion ◽

Polarization Transfer ◽

Nitrogen Vacancy ◽

Nitrogen Vacancy Center ◽

Direct Polarization ◽

Solid Effect ◽

First Time ◽

Acid Sample

Abstract. We demonstrate room-temperature 13C hyperpolarization by dynamic nuclear polarization (DNP) using optically polarized triplet electron spins in two polycrystalline systems: pentacene-doped [carboxyl-13C] benzoic acid and microdiamonds containing NV- centers. For both samples, the integrated solid effect (ISE) is used to polarize the 13C spin system in magnetic fields of 350–400 mT. In the benzoic acid sample, the 13C spin polarization is enhanced up to 0.12 % through direct electron-to-13C polarization transfer without performing dynamic 1H polarization followed by 1H-13C cross polarization. In addition, ISE has been successfully applied for the first time to polarize naturally abundant 13C spins in a microdiamond sample to 0.01 %. To characterize the buildup of the 13C polarization, we discuss the efficiencies of direct polarization transfer between the electron and 13C spins as well as that of 13C–13C spin diffusion, examining various parameters which are beneficial or detrimental for successful bulk dynamic 13C polarization.

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