Effect of nuclear spin relaxation on intensity pattern of multiplet spectra in chemically induced dynamic nuclear polarization

1972 ◽  
Vol 94 (3) ◽  
pp. 1002-1004 ◽  
Author(s):  
K. Mueller ◽  
G. L. Closs
Keyword(s):  
Spin Relaxation ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Spin ◽  
Nuclear Polarization ◽  
Nuclear Spin Relaxation ◽  
Intensity Pattern ◽  
Chemically Induced

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.

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.

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