Synthetic method development and molecular weight control for homo- and co-polysilynes, silicon-based network-backbone polymers

Optimized methods for the syntheses of polyaryl, polyalkyl, and co-polysilynes, using sonochemically-emulsified NaK alloy reductions of trichlorosilanes, are reported. The methods give oxygen and solvent-impurity free polymers, by FTIR and 1H NMR, for poly(phenylsilyne) 1, poly(n-butylsilyne) 2, poly(ethylsilyne) 3, poly(n-propylsilyne) 4, and poly(cyclohexylsilyne) 5. Syntheses of the novel polysilynes poly(isobutylsilyne) 6, poly(amylsilyne) 7, and poly(phenyl-co-butylsilyne) 8 are also reported. The polymers were assessed for the photooxidation behavior that is characteristic of these inorganic network-backbone polymers. A method of molecular weight control for polysilynes, by combining monomers that bear substituents of differing steric size (n-butyltrichlorosilane and cyclohexyltrichlorosilane), is also reported.