The first stable dibenzosilafulvene, 9-{[8-(dimethylaminomethyl)-l-naphthyllphenylsil-1-ylium}fluoren-9-ide (Ta), was obtained in one step from 9-fluorenyllithium and chloro[8-(dimethylarninomethyl)-l-naphthyllphenylsilane as a stable solvate with THF. The structure of the zwitterionic compound 7a was established by IH, 13C, and 29Si NMR in solution and in the solid state. The reactions of compound 7a with crotonaldehyde, ethanol, and triethylethylidenephosphorane are described. 1"he data on the synthesis of alkoxy-and alkylthiochloro-9-fluorenylsilanes and their phosphortium salts are given.