Soluble polysilane characterization

We have recently synthesized and characterized a variety of soluble, substituted polysilane homopolymers by the condensation of appropriately substituted methylsilyl dichlorides with sodium dispersion as shown below and in Table I... 

Soluble and well-characterized polygermane homopolymers. (R Ciel,. and their copolymers with polysilanes have been prepared by the alkali metal coupling of diorgano-stbstiluled dihalogermancs, via clectrochemicul methods, and by tnmsition-metal catalyzed routes, as with the synthesis of polysilanes. 

Interest in polysilanes was reawakened in 1975, when Yajima and Hayashi found that permethylpolysilane could be transformed into silicon carbide by heating at high temperatures. Soon afterward, papers on soluble, meltable polysilanes began to appear. The literature on polysilanes has grown rapidly since that time. The early focus on the synthesis and simple characterization of polysilanes has given way to detailed physical studies of the structure of these polymers, and of their electronic and photophysical properties. 

Together with the solid phenylated cyclosilanes isolated from these reactions, there were also obtained rather large quantities of viscous liquid materials which have not as yet been fully characterized. Partial separation of these oils was achieved by fractionation from acetone. Some less soluble portions appeared to be materials made up of only diphenylsilylene units. Cryoscopic determinations of various fractions indicated multiples of Si(C6H5)2 ranging from seven to nine, and chemical evidence seemed to indicate that the materials were cyclic polysilanes. ... 

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