Dynamic nuclear polarization in highly fluorinated solutions
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Date
2010
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Publisher
Taylor & Francis
Abstract
The Overhauser effect type dynamic nuclear polarization experiments were performed to study solutions of the stable free radical alpha,gamma-Bisdiphenylene-beta-phenyl allyl complex with benzene (1:1) in some highly fluorinated aliphatic and aromatic solvents. In solutions examined in this study, it occurs mainly the Overhauser effect, which normally arises due to both dipolar and scalar interactions between the unpaired electrons of the free radical molecules and fluorine nuclei of solvent molecules. 1-Iodotridecafluorohexane, N-Methyl-bis-trifluoroacetamide, Octafluorotoluene and Hexafluorobenzene were used as the solvents. The experiments were performed at a low field double resonance NMR spectrometer, which operates at 1.53 mT. The NMR enhancements depend on competition between intermolecular magnetic interactions. It was studied to investigate variation of EPR spectra with four different temperatures. It was found as temperature increases, peak points of EPR spectra decreases.
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Keywords
Dynamic nuclear polarization, EPR spectra, Fluorine-electron double resonance, Free radical, Overhauser effect, Electron-double-resonance, Low magnetic-fields, Paramagnetic-resonance, Oximetry, Suspensions, Science, Chemistry, Benzene, Complexation, Electron resonance, Experiments, Fluorine, Free radicals, Nuclear magnetic resonance, Organic solvents, Quantum theory, Spectrometers, Spin polarization, Spin-lattice relaxation, Allyl complexes, Aromatic solvent, Double resonance, Dynamic nuclear polarization, EPR spectra, Hexafluorobenzene, Low field, Magnetic interactions, NMR spectrometer, Overhauser effect, Solvent molecules, Temperature increase, Trifluoroacetamides, Unpaired electrons, Electron spin resonance spectroscopy
Citation
Ovalıoğlu, H. vd. (2010). "Dynamic nuclear polarization in highly fluorinated solutions". Journal of Dispersion Science and Technology, 31(3), 332-337.