scholarly journals Dynamic Nuclear Polarization with Polychlorotriphenylmethyl Radicals: Supramolecular Polarization-Transfer Effects

2010 ◽  
Vol 49 (19) ◽  
pp. 3360-3362 ◽  
Author(s):  
Cristina Gabellieri ◽  
Veronica Mugnaini ◽  
Juan Carlos Paniagua ◽  
Nans Roques ◽  
Malena Oliveros ◽  
...  
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Polarization Transfer ◽  
Transfer Effects

Dynamic Nuclear Polarization with Polychlorotriphenylmethyl Radicals: Supramolecular Polarization-Transfer Effects

2010 ◽  
Vol 122 (19) ◽  
pp. 3432-3434 ◽  
Author(s):  
Cristina Gabellieri ◽  
Veronica Mugnaini ◽  
Juan Carlos Paniagua ◽  
Nans Roques ◽  
Malena Oliveros ◽  
...  
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Polarization Transfer ◽  
Transfer Effects

scholarly journals Boosting Dissolution-Dynamic Nuclear Polarization by Multiple-Step Dipolar Order Mediated 1H->13C Cross-Polarization

2021 ◽  
Author(s):  
Stuart J. Elliott ◽  
Olivier Cala ◽  
Quentin Chappuis ◽  
Samuel Cousin ◽  
Morgan Ceillier ◽  
...  
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Pulse Sequence ◽  
Polarization Transfer ◽  
Cross Polarization ◽  
Spin Order ◽  
Sample Dissolution ◽  
Dipolar Order ◽  
Multiple Step ◽  
Dissolution Dynamic Nuclear Polarization

<p>Dissolution-dynamic nuclear polarization can be boosted by employing multiplecontact cross-polarization techniques to transfer polarization from 1H to 13C spins. The method is efficient and significantly reduces polarization build-up times, however, it involves high-power radiofrequency pulses in a superfluid helium environment which limit its implementation and applicability and prevent a significant scaling-up of the sample size.</p> <p>We propose to overcome this limitation by a stepwise transfer of polarization using a lowenergy and low-peak power radiofrequency pulse sequence where the 1H®13C polarization transfer is mediated by a dipolar spin order reservoir. An experimental demonstration is presented for [1-13C]sodium acetate. A solid-state 13C polarization of ~43.5% was achieved using this method with a build-up time constant of ~5.1 minutes, leading to a ~28.5% 13C polarization in the liquidstate after sample dissolution. The low-power multiple-step polarization transfer efficiency with respect to the most advanced and highest-power multiple-contact cross-polarization approach was found to be ~0.69.</p>

scholarly journals Boosting Dissolution-Dynamic Nuclear Polarization by Multiple-Step Dipolar Order Mediated 1H->13C Cross-Polarization

2021 ◽  
Author(s):  
Stuart J. Elliott ◽  
Olivier Cala ◽  
Quentin Chappuis ◽  
Samuel Cousin ◽  
Morgan Ceillier ◽  
...  
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Pulse Sequence ◽  
Polarization Transfer ◽  
Cross Polarization ◽  
Spin Order ◽  
Sample Dissolution ◽  
Dipolar Order ◽  
Multiple Step ◽  
Dissolution Dynamic Nuclear Polarization

<p>Dissolution-dynamic nuclear polarization can be boosted by employing multiplecontact cross-polarization techniques to transfer polarization from 1H to 13C spins. The method is efficient and significantly reduces polarization build-up times, however, it involves high-power radiofrequency pulses in a superfluid helium environment which limit its implementation and applicability and prevent a significant scaling-up of the sample size.</p> <p>We propose to overcome this limitation by a stepwise transfer of polarization using a lowenergy and low-peak power radiofrequency pulse sequence where the 1H®13C polarization transfer is mediated by a dipolar spin order reservoir. An experimental demonstration is presented for [1-13C]sodium acetate. A solid-state 13C polarization of ~43.5% was achieved using this method with a build-up time constant of ~5.1 minutes, leading to a ~28.5% 13C polarization in the liquidstate after sample dissolution. The low-power multiple-step polarization transfer efficiency with respect to the most advanced and highest-power multiple-contact cross-polarization approach was found to be ~0.69.</p>

scholarly journals Dipolar order mediated <sup>1</sup>H → <sup>13</sup>C cross-polarization for dissolution-dynamic nuclear polarization

2020 ◽  
Vol 1 (1) ◽  
pp. 89-96
Author(s):  
Stuart J. Elliott ◽  
Samuel F. Cousin ◽  
Quentin Chappuis ◽  
Olivier Cala ◽  
Morgan Ceillier ◽  
...  
Keyword(s):  
Small Molecules ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Polarization Transfer ◽  
Cross Polarization ◽  
Resonance Imaging ◽  
Dipolar Order ◽  
Imaging And Spectroscopy ◽  
Single Polarization ◽  
Dissolution Dynamic Nuclear Polarization

Abstract. Magnetic resonance imaging and spectroscopy often suffer from a low intrinsic sensitivity, which can in some cases be circumvented by the use of hyperpolarization techniques. Dissolution-dynamic nuclear polarization offers a way of hyperpolarizing 13C spins in small molecules, enhancing their sensitivity by up to 4 orders of magnitude. This is usually performed by direct 13C polarization, which is straightforward but often takes more than an hour. Alternatively, indirect 1H polarization followed by 1H→13C polarization transfer can be implemented, which is more efficient and faster but is technically very challenging and hardly implemented in practice. Here we propose to remove the main roadblocks of the 1H→13C polarization transfer process by using alternative schemes with the following: (i) less rf (radiofrequency) power; (ii) less overall rf energy; (iii) simple rf-pulse shapes; and (iv) no synchronized 1H and 13C rf irradiation. An experimental demonstration of such a simple 1H→13C polarization transfer technique is presented for the case of [1-13C]sodium acetate, and is compared with the most sophisticated cross-polarization schemes. A polarization transfer efficiency of ∼0.43 with respect to cross-polarization was realized, which resulted in a 13C polarization of ∼8.7 % after ∼10 min of microwave irradiation and a single polarization transfer step.

scholarly journals Dipolar Order Mediated <sup>1</sup>H→<sup>13</sup>C Cross-Polarization for Dissolution-Dynamic Nuclear Polarization

2020 ◽  
Author(s):  
Stuart J. Elliott ◽  
Samuel F. Cousin ◽  
Quentin Chappuis ◽  
Olivier Cala ◽  
Morgan Ceillier ◽  
...  
Keyword(s):  
Small Molecules ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Polarization Transfer ◽  
Cross Polarization ◽  
Rf Power ◽  
Dipolar Order ◽  
Imaging And Spectroscopy ◽  
Single Polarization ◽  
Dissolution Dynamic Nuclear Polarization

Abstract. Magnetic resonance imaging and spectroscopy often suffer from a low intrinsic sensitivity, which can in some cases be circumvented by the use of hyperpolarization techniques. Dissolution-dynamic nuclear polarization offers a way of hyperpolarizing 13C spins in small molecules, enhancing their sensitivity by up to four orders of magnitude. This is usually performed by direct 13C polarization, which is straightforward but often takes more than an hour. Alternatively, indirect 1H polarization followed by 1H→13C polarization transfer can be implemented, which is more efficient and faster but is technically very challenging and hardly implemented in practice. Here we propose to remove the main roadblocks of the 1H→13C polarization transfer process by using alternative schemes with: (i) less rf-power; (ii) less overall rf-energy; (iii) simple rf-pulse shapes; and (iv) no synchronized 1H and 13C rf-irradiation. An experimental demonstration of such a simple 1H→13C polarization transfer technique is presented for the case of [1-13C]sodium acetate, and is compared with the most sophisticated cross-polarization schemes. A polarization transfer efficiency of ~ 0.43 with respect to cross-polarization was realized, which resulted in a 13C polarization of ~ 8.7 % after ~ 10 minutes of microwave irradiation and a single polarization transfer step.

scholarly journals PRESTO polarization transfer to quadrupolar nuclei: implications for dynamic nuclear polarization

2015 ◽  
Vol 17 (35) ◽  
pp. 22616-22622 ◽  
Author(s):  
Frédéric A. Perras ◽  
Takeshi Kobayashi ◽  
Marek Pruski
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Polarization Transfer ◽  
Quadrupolar Nuclei

We show both experimentally and numerically that in experiments involving transfer of magnetization from 1H to the quadrupolar nuclei under MAS, the PRESTO technique consistently outperforms the traditionally used CP method, affording more quantitative intensities, improved lineshapes, better sensitivity, and easier optimization.

High frequency (140 GHz) dynamic nuclear polarization: Polarization transfer to a solute in frozen aqueous solution

1995 ◽  
Vol 102 (24) ◽  
pp. 9494-9497 ◽  
Author(s):  
G. J. Gerfen ◽  
L. R. Becerra ◽  
D. A. Hall ◽  
R. G. Griffin ◽  
R. J. Temkin ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Dynamic Nuclear Polarization ◽  
High Frequency ◽  
Nuclear Polarization ◽  
Polarization Transfer

scholarly journals Targetable Tetrazine-Based Dynamic Nuclear Polarization Agents for Biological Systems

2019 ◽  
Author(s):  
Byung Joon Lim ◽  
Bryce E. Ackermann ◽  
Galia T. Debelouchina
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Mammalian Cells ◽  
Nuclear Polarization ◽  
Biological Systems ◽  
Polarization Transfer ◽  
Unnatural Amino Acid ◽  
Great Promise ◽  
Cellular Environment ◽  
Transfer Mechanisms ◽  
Complex Polarization

AbstractDynamic nuclear polarization (DNP) has shown great promise as a tool to enhance the nuclear magnetic resonance (NMR) signals of proteins in the cellular environment. As the sensitivity increases, the ability to select and efficiently polarize a specific macromolecule over the cellular background has become desirable. Here, we address this need and present a tetrazine-based DNP polarization agent that can be targeted selectively to proteins containing the unnatural amino acid (UAA) norbornene-lysine. The UAA can be introduced efficiently by genetic means in the cellular milieu. Our approach is bio-orthogonal and easily adaptable to any protein of interest. We illustrate the scope of our methodology and investigate the DNP polarization transfer mechanisms in several biological systems. Our results present the first molecular view of the complex polarization transfer pathways in targeted DNP and ultimately pave the way to selective DNP-enhanced NMR spectroscopy in both bacterial and mammalian cells.

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