| Autor: |
Chen H; Department of Chemistry, The University of Alabama, Box 870336, Tuscaloosa, Alabama 35487-0336, USA. mkbowman@ua.edu., Maryasov AG, Rogozhnikova OY, Trukhin DV, Tormyshev VM, Bowman MK |
| Jazyk: |
angličtina |
| Zdroj: |
Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2016 Sep 28; Vol. 18 (36), pp. 24954-65. Date of Electronic Publication: 2016 Aug 25. |
| DOI: |
10.1039/c6cp02649d |
| Abstrakt: |
Electron spin-lattice relaxation of two trityl radicals, d24-OX063 and Finland trityl, were studied under conditions relevant to their use in dissolution dynamic nuclear polarization (DNP). The dependence of relaxation kinetics on temperature up to 100 K and on concentration up to 60 mM was obtained at X- and W-bands (0.35 and 3.5 Tesla, respectively). The relaxation is quite similar at both bands and for both trityl radicals. At concentrations typical for DNP, relaxation is mediated by excitation transfer and spin-diffusion to fast-relaxing centers identified as triads of trityl radicals that spontaneously form in the frozen samples. These centers relax by an Orbach-Aminov mechanism and determine the relaxation, saturation and electron spin dynamics during DNP. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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