Solid-State NMR (19F and 13C) Study of Graphite Monofluoride (CF)n: 19F Spin−Lattice Magnetic Relaxation and 19F/13C Distance Determination by Hartmann−Hahn Cross Polarization
| Autor: | William E. E. Stone, André Hamwi, Jérôme Giraudet, Pascal Pirotte, Francis Masin, Marc Dubois |
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| Rok vydání: | 2004 |
| Předmět: |
Carbon-13 NMR satellite
Chemistry Monofluoride Relaxation (NMR) Analytical chemistry Surfaces Coatings and Films Bond length chemistry.chemical_compound Solid-state nuclear magnetic resonance Materials Chemistry Magic angle spinning Transverse relaxation-optimized spectroscopy Physical and Theoretical Chemistry Magnetic dipole–dipole interaction |
| Zdroj: | The Journal of Physical Chemistry B. 109:175-181 |
| ISSN: | 1520-5207 1520-6106 |
| Popis: | Graphite monofluoride (CF)(n) was studied by solid-state NMR. (19)F spin-lattice relaxation time T(1) and second moment measurements of the (19)F line are presented. A "chair" conformation structure is found to be compatible with the experimental data. Relaxation is shown to be mainly due to paramagnetic oxygen. The presence of a molecular motion with an activation energy of 1.685 kJ.mol(-1) (202.7 K) is also evidenced. (19)F magic angle spinning (MAS) NMR and (13)C MAS NMR with (19)F to (13)C cross-polarization allows the determination of CF and CF(2) groups. Reintroduction of dipolar coupling by cross-polarization is used for C-F bond length determination (0.138 +/- 0.001 nm). |
| Databáze: | OpenAIRE |
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