Synthesis of Poly(silylenemethylenes) through Reactions Carried Out on Preformed Polymers. 1. Replacement of the Chloro Group in Poly[(chloromethylsilylene)methylene]

A new series of poly(silylenemethylenes) of the type [Si(Me)(X)CH2] n , where X = OR (R = Et, CH2CF3, Ph, Ac), F, and R‘ (R‘ = n-butyl, allyl), were obtained starting from the preformed [Si(Me)(Cl)CH2] n polymer. The OR derivatives were obtained quantitatively from the [Si(Me)(Cl)CH2] n polymer by treatment with ROH/Et3N or NaOR. Reaction of the [Si(Me)(Cl)CH2] n polymer with the allyl Grignard reagent also gave 100% substitution, but the reaction with the n-butyl Grignard reagent was found to proceed only to the extent of ∼70%. The novel [Si(Me)(F)CH2] n polymer was obtained by the action of BF3·Et2O on the [Si(Me)(OEt)CH2] n polymer. The atactic structures of these polymers were characterized by NMR spectroscopy, and their molecular weights and thermal properties were examined by GPC, DSC, and TGA. The [Si(Me)(OR)CH2] n polymers were found to vary widely in terms of their hydrolytic sensitivity and glass transition temperatures.