Solution and X-ray structure of triethylsilylmethyl-substituted tropylium cation

Abstract

Matrix presented. The β-silyl tropylium cation 9 has been successfully generated in the presence of the noncoordinating counterion tetrakis(pentafluorophenyl)-borate in benzene and toluene. The 13C and 29Si NMR spectra of 9 demonstrate that the β-silicon substituent interacts strongly with the aromatic π-system of the cation by hyperconjugation. The crystal structure of 9 shows structural effects consistent with this interaction.