POLYMERIZATION OF 1-ARYL-2-TRIMETHYLSILYLACETYLENES BY TRANSITION-METAL CATALYSTS(II)

Polymerization of 1-aryl-2-trimethylsilylacetylene (aryl = thienyl, furly, and pyridyl) was carried out by transition metal catalysts. The polymer yield was generally low due to the steric hindrance. R4Sn (R=Me, n-Bu, Ph) exhibits some cocatalytic activities with respect to polymer yield and molecular weight. On the other hand, the polymerization was decelerated when organoaluminum compounds were used as cocatalysts. The polymer yield increased in the following order: phenyl $GR thienyl $GR furyl $GR pyridyl, according to the aryl substituents. The NMR (1H- and 13C-), IR, and UV-visible spectra indicated that the resulting polymers have a linear conjugated polyene structure each containing the aromatic substituent and trimethylsilyl group. From 1H-NMR integration, it was found that the resulting polymers are partially desilylated depending on the substituents of monomer and the polymerization conditions. The solubility behavior, stability and fluoride-ion induced desilylation reaction of the polymers were also studied.