The First Organosilver(III) Fluoride, [PPh4 ][(CF3 )3 AgF]

Chemistry. 2020 Apr 6;26(20):4471-4475. doi: 10.1002/chem.201905771. Epub 2020 Feb 19.

Abstract

Organosilver(III) fluoride complexes have been assigned a key role in different fluorination processes. To the best of our knowledge, however, none of them seem to have been isolated or even detected thus far. Here we report on the successful synthesis of the trifluoromethyl derivative [PPh4 ][(CF3 )3 AgF], which has been isolated in high yield. The thermodynamic stability of the Ag-F bond is shown by calculation and demonstrated by multistage mass spectrometry (MSn ) under collision-induced dissociation (CID) conditions. Nevertheless, the substantial elongation found in the Ag-F bond (X-ray) is correlated with a marked nucleophilic character of the terminal F ligand. This Ag-F bond is, in fact, quite reactive: it suffers hydrolysis and is also solvolyzed by thiols.

Keywords: fluorides; high oxidation state; organosilver(III); thiols; trifluoromethylation.