High DNP efficiency of TEMPONE radicals in liquid toluene at low concentrationsElectronic supplementary information (ESI) available: The DNP setup, evaluation of enhancements, comparison of leakage factors in toluene and water, power and concentration dependence of the TEMPONE CW-EPR line in toluene, EPR and ELDOR recovery curves at 0.1 and 3 mM TEMPONE concentrations, an estimate of exchange coupling from the EPR line width. See DOI: 10.1039/c4cp00854e
We show that at low concentrations (≤5 mM) TEMPONE radicals in liquid toluene exhibit higher DNP efficiency than in water. In spite of reduced coupling factors, the improved DNP performance in toluene results from favourable saturation and leakage factors, as determined by pulse electron-electron do...
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| Main Authors | , , , |
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| Format | Journal Article |
| Language | English |
| Published |
16.04.2014
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| Online Access | Get full text |
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| Summary: | We show that at low concentrations (≤5 mM) TEMPONE radicals in liquid toluene exhibit higher DNP efficiency than in water. In spite of reduced coupling factors, the improved DNP performance in toluene results from favourable saturation and leakage factors, as determined by pulse electron-electron double resonance (ELDOR) and NMR relaxation, respectively. The extracted coupling factors at 0.35 Tesla support theoretical predictions of the Overhauser mechanism.
Dynamic nuclear polarization in liquid toluene with TEMPONE radicals leads to high NMR signal enhancements at low polarizer concentrations. |
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| Bibliography: | Electronic supplementary information (ESI) available: The DNP setup, evaluation of enhancements, comparison of leakage factors in toluene and water, power and concentration dependence of the TEMPONE CW-EPR line in toluene, EPR and ELDOR recovery curves at 0.1 and 3 mM TEMPONE concentrations, an estimate of exchange coupling from the EPR line width. See DOI 10.1039/c4cp00854e |
| ISSN: | 1463-9076 1463-9084 |
| DOI: | 10.1039/c4cp00854e |