Silver ion-assisted substitutive fluorination of chlorofullerenes

• Published in: Journal of fluorine chemistry Vol. 237; p. 109598
• Main Authors: Khavrel, Pavel A., Serov, Mikhail G., Petukhova, Galina G., Markov, Vitaliy Yu, Goryunkov, Alexey A.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-09-2020; Elsevier BV
• Subjects: Anions; Chlorine; Chlorine compounds; Density functional calculations; Fluorides; Fluorination; Fullerenes; Halogenated fullerenes; Isomers; NMR; NMR spectroscopy; Nuclear magnetic resonance; Reaction mechanisms; Silver; Halogenated fullerenes; Density functional calculations; NMR spectroscopy; Reaction mechanisms
• ISSN: 0022-1139; 1873-3328
• DOI: 10.1016/j.jfluchem.2020.109598

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•Silver monofluoride fluorinates chlorofullerenes yielding novel fullerene halides.•Cl/F exchange pathway preserves the initial addition pattern.•According to DFT studies Ag+-promoted Halex process occurs via cationic intermediates.
Treatment of the skew-pentagonal-pyramid (SPP) isomer of C60Cl6 with silver(I) fluoride affords displacement of chlorine addends to give mixed C60Cl6–nFn compounds with n = 1–5 and pure C60Fn fluorides with n = 2, 4, and 6. Likewise, treatment of Cs-C70Cl10 produces C70Fn fluorides with n = 2–10 and a series of mixed chloro-fluoro derivatives. Several of the newly synthesized substances, SPP-C60Cl5F, SPP-C60ClF5 (two isomers), SPP-C60F6, and non-symmetric C60F4 and C60F6, have been isolated, and spectroscopically characterized. Their structures have been established on the basis of the 19F NMR data supplemented with DFT calculations. Our experimental data and theoretical considerations suggest that the reaction likely proceeds via Ag+-mediated elimination of chloride anion from the fullerene cage followed by fluoride anion attachment to the site thus vacated.