Chemical transformations of functional polycarbosilanes

The functional polycarbosilane Si(X ₂)C₂H₄] _n , whereX ₂=Cl₂ (1), was chemically transformed into the corresponding polymers, whereX ₂=F₂ (3), (2-N, N-dimethylbenzylamino)(H) (5), (9-N,N-dimethyl-1-naphthylamino)(H) (6), (1-C₁₀H₇)(H) (7), Me₂ (8a), (Me₃SiNH)₂ (10), and (vinyl)(H) (11). The functional polycarbosilane, whereX ₂=H₂ (2), was converted into the polymers, whereX ₂=Me(H) (8b) and (OMe)₂ (9). Reaction of3 with KF in the presence of 18-crown-6 gave rise to the poycarbosilane4 containing both pentacoordinate and tetracoordinate silicons in the proportion of 1:15 as shown by quantitative¹⁹F and²⁹Si NMR. Conversion of a greater proportion of silicon atoms to the pentacoordinate state was not possible because of insolubility of the resulting ionomer in the reaction medium.