Discrete GeF Anion Structurally Characterized with a Readily Synthesized Imidazolium Based Naked Fluoride Reagent.

The recently prepared novel naked fluoride reagent 1,3-bis(2,6-diisopropylphenyl)imidazolium fluoride ([(L)H][F]), treated with an excess of MF (M = Si, Ge), results in isolation of [(L)H][MF] products with the elusive trigonal bipyramidal MF anions. Specific steric characteristics of the [(L)H] cation readily support isolation of monomeric and discrete trigonal bipyramidal fluorido anions of silicon and germanium. Based on combination of experimental results and DFT calculations, we demonstrate that the role of bulky cation is not solely due to steric hindering but also due to electrostatic effects, which are important in the design of such uncommon species. The discrete GeF anion was characterized by X-ray single-crystal diffraction for the first time. We report the missing F NMR entries for the discrete GeF and GeF anions in acetonitrile. All the products were also characterized by Raman spectroscopy and elemental analysis and supported by quantum-mechanical calculations.