Oxidative Coupling Polymerization of Diethynylsilane Derivatives and 1,2-Diethynyl-1,1,2,2-tetramethyldisilane

We have carried out the Glaser oxidative coupling polymerizations of diethynyldiphenylsilane, diethynylmethylphenylsilane,diethynylmethyloctylsilane, and 1,2-diethynyl-1,1,2,2-tetramethyldisilane to afford polycarbosilanes containing diethynyl and organosilane groups in the main chain, such as poly(diethynyldiphenylsilane), poly(diethynylmethylphenylsilane), poly(diethynylmethyloctylsilane), and poly(1,2-diethynyl-1,1,2,2-tetramethyldisilane), respectively. These obtained materials are almost insoluble in common organic solvents such as $CHCl_3$ and THF probably due to the presence of a rigid rod diacetylene group along the polymer main chain. Therefore, the polymers were characterized using several spectroscopic methods in solid state. FTIR spectra of all the polymeric materials show that the characteristic $C \equiv C$ stretching frequencies appear at 2147-2154 $cm ^{-1}$, in particular. The polymers in the solid state exhibit that the strong maximum excitation peaks appear at 260-283 nm and the strong maximum fluorescence emission bands at 367-412 nm, especially. Thermogravimetric analysis of the materials shows that about 55-68% of the initial polymer weights remain at 400 ${^{\circ}C}$ in nitrogen.