Synthesis and Metathesis Polymerization of New Monomer 7-Trimethylsilyltricyclo[4.2.2.0^2,5]deca-3,9-diene

The reaction of 1,3,5,7-cyclooctatetraene with silicon-substituted ethylenes has been studied for the first time. It is shown that vinyltrimethylsilane is inactive in the reaction, and vinyltrichlorosilane forms 7-trichlorosilyltricyclo[4.2.2.0^2,5]deca-3,9-diene in up to 12% yield. A new silicon-substituted monomer 7‑trimethylsilyltricyclo[4.2.2.0^2,5]deca-3,9-diene containing 92% of the endo-isomer has been synthesized by methylation of the chloroadduct. The metathesis polymerization of the final monomer mediated by the Grubbs Ru catalysts of the first and second generations is studied. A new poly(7-trimethylsilyltricyclo[4.2.2.0^2,5]deca-3,9-diene) containing a bulky bicyclic fragment and predominantly trans-double bonds in the main chain (up to 94%) is obtained in 90–96% yields. The polymer is characterized by the highest glass transition point (187°C) in the series of monotrimethylsilyl-substituted polynorbornenes. The double bonds present in the monomer unit open up prospects for further modification.