par Giraudet, Jérôme ;Dubois, Marc;Hamwi, André;Stone, William ;Pirotte, Pascal ;Masin, Francis
Référence Journal of Physical Chemistry (1952), 109, 1, page (175-181)
Publication Publié, 2005
Référence Journal of Physical Chemistry (1952), 109, 1, page (175-181)
Publication Publié, 2005
Article révisé par les pairs
Résumé : | 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). |