Solid-state 19F and 13C NMR of room temperature fluorinated graphite and samples thermally treated under fluorine: Low-field and high-resolution studies

• Published in: Journal of solid state chemistry Vol. 178; no. 4; pp. 1262 - 1268
• Main Authors: Giraudet, J., Dubois, M., Guérin, K., Pinheiro, J.P., Hamwi, A., Stone, W.E.E., Pirotte, P., Masin, F.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.04.2005; Elsevier
• Subjects: Chemical and knight shifts; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Fluorine; Graphite fluoride; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Nuclear magnetic resonance (NMR); Nuclear magnetic resonance and relaxation; Physics; Fluorine; Graphite fluoride; Nuclear magnetic resonance (NMR); Temperature dependence; Inorganic compounds; Scattering; Cross polarization; Binary compounds; Graphite Fluorides; Nuclear magnetic resonance; Nuclear magnetic resonance (NMR): Fluorine; Experimental study; Heat treatments; Covalent bonds
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2005.01.024

Room temperature graphite fluorides consisting of raw material and samples post-treated in pure fluorine atmosphere in the temperature range 100–500 °C have been studied by solid-state NMR. Several NMR approaches have been used, both high and low-field 19F, 19F MAS and 13C MAS with 19F to 13C cross polarization. The modifications, in the graphitic lattice, of the catalytic iodine fluorides products have been examined. A transformation of the C–F bond character from semi-ionic to covalent has been found to occur at a post-treatment temperature close to 400 °C. It is shown that covalency increases with temperature. 19F spectra (18.9 MHz) of CF– T samples, T is the temperature of post-treatment (TPT). All spectra are shown with constant S / N ratio.