Aldiminium Cations as Countercations to Discrete Main Group Fluoroanions.

The reactions of group 14 tetrafluorides (SiF 4 , GeF 4 , and SnF 4 ) and group 15 pentafluorides (PF 5 , AsF 5 , and SbF 5 ) with the CAAC-based trifluoride reagent [ Me CAACH][F(HF) 2 ] led to the isolation of salts containing discrete 5- or 6-coordinated fluoroanions. The syntheses of [ Me CAACH][SiF 5 ], [ Me CAACH][GeF 5 ], [ Me CAACH][(THF)SnF 5 ], and the structurally related [ Me CAACH][(dioxane)SnF 5 ], [ Me CAACH][PF 6 ], [ Me CAACH][AsF 6 ], and [ Me CAACH][SbF 6 ] are effective, selective and in high yield. All compounds were characterized by X-ray single-crystal structure analysis, NMR and Raman spectroscopy. It is worth noting that the synthesized [ Me CAACH][GeF 5 ] is a rare example of a structurally characterized compound with discrete [GeF 5 ] - anion, while [ Me CAACH][(THF)SnF 5 ] and [ Me CAACH][(dioxane)SnF 5 ] represent the first compounds with discrete octahedrally coordinated tin fluoride anions with incorporated solvent molecules. Finally, the aldiminium-based cation [ Me CAACH] + proved to be suitable for the stabilization of rare discrete main group fluoride anions.