STRUCTURE IN AMORPHOUS POLYSILANES DETERMINED BY DIFFUSE-X-RAY SCATTERING

Polyphenylsilane, (HSiC6H5)(n), was synthesised by catalytic coupling of phenylsilane using Cp(2)ZrCl(2)nBuLi as a catalyst. Chlorination of the resulting polymer with tetrachloromethane (CCl4) gave polychlorop henylsilane, (ClSiC6H5)(n), subsequent substitution of chloride by dim ethylamine yielded polydimethylaminophenylsilane, ((CH3)(2)NSiC6H5)(n) The X-ray pattern of the three polysilanes reveal their amorphous sta te. Due to the similarity of the X-ray pattern of the three polysilane s, diffraction peaks are observed at s similar to 0.6, 1.4 and 3.3 Ang strom(-1), similar conformation and packing of the polysilane chains a re concluded. The peaks at 0.6 Angstrom(-1) are identified as intercha in peaks. From a comparison of the reduced scattering functions of pol yphenylsilane and liquid benzene, we conclude that the arrangement of phenyl rings in polyphenylsilane is comparable to the statistical diso rder of benzene molecules in the liquid state. (C) 1998 Elsevier Scien ce Ltd. All rights reserved.