POLYMERIC ORGANOSILICON SYSTEMS .11. SYNTHESIS AND SOME PROPERTIES OF POLY(DISILANYLENEBUTENYNE-1,4-DIYLS) AND POLY[(METHYLPHENYLSILYLENE)BUTENYNE-1,4-DIYL]

Three types of poly(disilanylenebutenyne-1,4-diyls) were synthesized by rhodium(I)-catalyzed head-to-head coupling of diethynyldisilanes. Poly[(methylphenylsilylene)butenyne-1,4-diyl] was also prepared by the rhodium(I)-catalyzed reaction of diethynylmethylphenylsilane. Copolymerization of 1,2-diethynyltetraphenyldisilane and 1,2-diethynyltetramethyldisilane in a ratio of 1:1 afforded an alternating polymer. Molecular weights of the polymers obtained were determined to be M(w) = 10 000-100 000 by GPC relative to polystyrene standards. The poly(disilanylenebutenyne-1,4-diyls) were found to be highly photoactive. Irradiation of these polymers with UV light caused scission of Si-Si bonds in the polymer backbone in solid state and also in solution. In contrast to these polymers, poly[(methylphenylsilylene)butenyne-1,4-diyl] was found to be photochemically stable. The polymers can be cast to thin solid films by spin-coating. When the thin solid films prepared from the poly(disilanylenebutenyne-1,4-diyls) were doped with SbF5 vapor, highly conducting films whose conductivities were measured by the four-probe method to be 10(-3)-10(0) S.cm-1 in air and 10(-4)-10(-3) S.cm-1 in vacuo were obtained.