Synthesis of imidazolium-based pentacoordinated organofluorosilicate and germanate salts.

The syntheses of a new triphenyldifluorogermanate and various pentacoordinated organofluorosilicates are presented. The fluorogermane and fluorosilane compounds were obtained from the corresponding chlorosilanes and chlorogermane by halogen substitution with KF. Subsequent reaction with the imidazolium-based fluoride reagent [IPrH][F] (1,3-bis(2,6-diisopropylphenyl)imidazolium fluoride) led to the formation of [IPrH][Ph 3 SiF 2 ] (1), [IPrH][Ph 2 SiF 3 ] (3), [IPrH][Et 2 SiF 3 ] (4), [IPrH][PhSiF 4 ] (5), [IPrH][EtSiF 4 ] (6) and [IPrH][Ph 3 GeF 2 ] (7). All the products obtained were characterised by NMR, Raman spectroscopy and X-ray diffraction. The results were supported by DFT calculations of the structurally optimised compounds.