Strengthening of the C-F Bond in Fumaryl Fluoride with Superacids

Bayer, Marie C.; Kremser, Christoph; Jessen, Christoph; Nitzer, Alexander und Kornath, Andreas J. (2022): Strengthening of the C-F Bond in Fumaryl Fluoride with Superacids. In: Chemistry - A European Journal, Bd. 28, Nr. 15

Abstract

The reaction of fumaryl fluoride with the superacidic solutions XF/MF5 (X=H, D;M=As, Sb) results in the formation of the monoprotonated and diprotonated species, dependent on the stoichiometric ratio of the Lewis acid to fumaryl fluoride. The salts [C4H3F2O2](+)[MF6](-) (M=As, Sb) and [C4H2X2F2O2](2+)([MF6](-))(2) (X=H, D;M=As, Sb) are the first examples with a protonated acyl fluoride moiety. They were characterized by low-temperature vibrational spectroscopy. Low-temperature NMR spectroscopy and single-crystal X-ray structure analyses were carried out for [C4H3F2O2](+)[SbF6](-) as well as for [C4H4F2O2](2+)([MF6](-))(2) (M=As, Sb). The experimental results are discussed together with quantum chemical calculations of the cations [C4H4F2O2 . 2 HF](2+) and [C4H3F2O2 . HF](+) at the B3LYP/aug-cc-pVTZ level of theory. In addition, electrostatic potential (ESP) maps combined with natural population analysis (NPA) charges were calculated in order to investigate the electron distribution and the charge-related properties of the diprotonated species. The C-F bond lengths in the protonated dication are considerably reduced on account of the +R effect.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie > Department Chemie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 0947-6539
• Sprache: Englisch
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 491502892