Efficient, “one‐pot” synthesis of silylene–acetylene and disilylene–acetylene preceramic polymers from trichloroethylene

An extremely efficient process has been developed for the synthesis of linear silylene‐acetylene and disilylene‐acetylene polymers. Trichloroethylene is quantitatively converted by n‐butyllithium to dilithioacetylene. Quenching with dialkyl‐or diaryldichlorosilanes affords high yields of the polymers, {article}{empty}{document}-- [ SiR₂ --- C ≡ C-- ]ₙ , and -- [ SiMe₂ SiMe₂ - C ≡ C-- ]ₙ{document} if ClMe2SiSiMe2Cl is employed. Molecular weights are much higher with this route than when acetylene is used as the dilithio‐ or dimagnesium acetylide precursor. Some of these polymers can be pulled into continuous fibers, and all can be cast into coherent films and thermally converted into silicon carbide.