σ–π Conjugated Organosilicon Hybrid Polymers from Copolymerization of a Tetrasiladiene and 1,4-Diethynylbenzene

摘要

A catalyst- and by-product-free protocol for the synthesis of s–p conjugated organosilicon polymers is reported. The regiospecific [2+2] cycloaddition of C≡C triple bonds to Si=Si double bonds allowed the preparation of air-stable ethynyl-terminated extended monomers from 1,4-bis(ethynyl)benzene and the para-phenylene bridged tetrasiladiene, Tip2Si=SiTip-pC_6H_4-SiTip=SiTip_2 (Tip=2,4,6-iPr_3C_6H_2). The polymer obtained from the extended monomer and further tetrasiladiene exhibits pronounced s–p conjugation, as was evident from the red-shift in the absorption spectrum compared to model systems. We show that the thermal stability of the employed bis(alkyne) comonomer is translated into this polymer.