Spin relaxation effects in photochemically induced dynamic nuclear polarization spectroscopy of nuclei with strongly anisotropic hyperfine couplings.
We describe experimental results and theoretical models for nuclear and electron spin relaxation processes occurring during the evolution of 19F-labeled geminate radical pairs on a nanosecond time scale. In magnetic fields of over 10 T, electron-nucleus dipolar cross-relaxation and longitudinal Delt...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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American Chemical Society
2007
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| _version_ | 1797056113513857024 |
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| author | Kuprov, I Craggs, T Jackson, SE Hore, P |
| author_facet | Kuprov, I Craggs, T Jackson, SE Hore, P |
| author_sort | Kuprov, I |
| collection | OXFORD |
| description | We describe experimental results and theoretical models for nuclear and electron spin relaxation processes occurring during the evolution of 19F-labeled geminate radical pairs on a nanosecond time scale. In magnetic fields of over 10 T, electron-nucleus dipolar cross-relaxation and longitudinal DeltaHFC-Deltag (hyperfine coupling anisotropy--g-tensor anisotropy) cross-correlation are shown to be negligibly slow. The dominant relaxation process is transverse DeltaHFC-Deltag cross-correlation, which is shown to lead to an inversion in the geminate 19F chemically induced dynamic nuclear polarization (CIDNP) phase for sufficiently large rotational correlation times. This inversion has recently been observed experimentally and used as a probe of local mobility in partially denatured proteins (Khan, F.; et al. J. Am. Chem. Soc. 2006, 128, 10729-10737). The essential feature of the spin dynamics model employed here is the use of the complete spin state space and the complete relaxation superoperator. On the basis of the results reported, we recommend this approach for reliable treatment of magnetokinetic systems in which relaxation effects are important. |
| first_indexed | 2024-03-06T19:18:47Z |
| format | Journal article |
| id | oxford-uuid:19582ea3-54af-4545-a491-4b5ab1f34ae3 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:18:47Z |
| publishDate | 2007 |
| publisher | American Chemical Society |
| record_format | dspace |
| spelling | oxford-uuid:19582ea3-54af-4545-a491-4b5ab1f34ae32022-03-26T10:48:28ZSpin relaxation effects in photochemically induced dynamic nuclear polarization spectroscopy of nuclei with strongly anisotropic hyperfine couplings.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:19582ea3-54af-4545-a491-4b5ab1f34ae3Theoretical chemistryComputational chemistryPhysical and theoretical chemistryEnglishSymplectic Elements at OxfordAmerican Chemical Society2007Kuprov, ICraggs, TJackson, SEHore, PWe describe experimental results and theoretical models for nuclear and electron spin relaxation processes occurring during the evolution of 19F-labeled geminate radical pairs on a nanosecond time scale. In magnetic fields of over 10 T, electron-nucleus dipolar cross-relaxation and longitudinal DeltaHFC-Deltag (hyperfine coupling anisotropy--g-tensor anisotropy) cross-correlation are shown to be negligibly slow. The dominant relaxation process is transverse DeltaHFC-Deltag cross-correlation, which is shown to lead to an inversion in the geminate 19F chemically induced dynamic nuclear polarization (CIDNP) phase for sufficiently large rotational correlation times. This inversion has recently been observed experimentally and used as a probe of local mobility in partially denatured proteins (Khan, F.; et al. J. Am. Chem. Soc. 2006, 128, 10729-10737). The essential feature of the spin dynamics model employed here is the use of the complete spin state space and the complete relaxation superoperator. On the basis of the results reported, we recommend this approach for reliable treatment of magnetokinetic systems in which relaxation effects are important. |
| spellingShingle | Theoretical chemistry Computational chemistry Physical and theoretical chemistry Kuprov, I Craggs, T Jackson, SE Hore, P Spin relaxation effects in photochemically induced dynamic nuclear polarization spectroscopy of nuclei with strongly anisotropic hyperfine couplings. |
| title | Spin relaxation effects in photochemically induced dynamic nuclear polarization spectroscopy of nuclei with strongly anisotropic hyperfine couplings. |
| title_full | Spin relaxation effects in photochemically induced dynamic nuclear polarization spectroscopy of nuclei with strongly anisotropic hyperfine couplings. |
| title_fullStr | Spin relaxation effects in photochemically induced dynamic nuclear polarization spectroscopy of nuclei with strongly anisotropic hyperfine couplings. |
| title_full_unstemmed | Spin relaxation effects in photochemically induced dynamic nuclear polarization spectroscopy of nuclei with strongly anisotropic hyperfine couplings. |
| title_short | Spin relaxation effects in photochemically induced dynamic nuclear polarization spectroscopy of nuclei with strongly anisotropic hyperfine couplings. |
| title_sort | spin relaxation effects in photochemically induced dynamic nuclear polarization spectroscopy of nuclei with strongly anisotropic hyperfine couplings |
| topic | Theoretical chemistry Computational chemistry Physical and theoretical chemistry |
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