Synthesis and structural characterization of trans-tactic siloxylene-vinylene-p-phenylene polymers via ADMET copolymerization and silylative coupling (SC) polycondensation

The first trans-tactic stereo-regular vinylene-siloxylene-p-phenylene copolymer 1 with perfect vinylsiloxane linkage was obtained via acyclic diene metathesis copolymerization of divinyltetraethoxydisiloxane with 1,4-divinylbenzene (DVB) in the presence of Grubbs catalyst. The similar trans-tactic copolymers 2 and 3 but with no consecutive vinylsiloxane linkage was also prepared by silylative coupling copolycondensation of DVB with divinyltetra(methyl,ethoxy)disiloxane catalyzed by [Ru(H)(Cl)(CO)(PCy3)2].