Synthesis and Properties of Poly(1,1-diethynyl-1-silacyclopent-3-enes and -1-silacyclobutane)

摘要

Polycarbosilanes containing diacetylene and organosilacyclic groups, such as poly(1,1-diethynyl-1- silacyclopent-3-ene), poly(1,1-diethynyl-3-triethylsilyl-1-silacyclopent-3-ene), and poly(1,1-diethynyl-1- silacyclobutane), were synthesized by the Glaser oxidative coupling polymerization reactions of 1,1-diethynyl- 1-silacyclopent-3-ene, 1,1-diethynyl-3-triethylsilyl-1-silacyclopent-3-ene, and 1,1-diethynyl-1-silacyclobutane, respectively. These materials are almost insoluble in usual organic solvents such as CHCl3 and THF. The polymers were characterized by using several spectroscopic methods in solid state. FTIR spectra of all the polymeric materials show that the characteristic CìC stretching frequencies appear at 2146-2170 cm-1, in particular. The polymers in the solid state show that the strong maximum excitation peaks appear at 255-257 nm and the strong maximum fluorescence emission bands at 401-402 nm. About 71-87% of the initial polymer weights remain at 400 oC in nitrogen according to thermogravimetric analysis.