Abstract: Polysilanes containing four membered rings with Si-Nbonds in the backbone were synthesized by cocondensation of methyl (β- phenethyl) dichlorosilane (or diphenyldichlorosilane ) and N,N'-bis-(chlorodimethylsilyl)tetramethylcylclodisilazane with sodium metal in toluene. The polymers possess higher molecular weights, lower softening points, better solubilities in common solvents. By casting the solution of each of the polymers in toluene on a glass plate, an elastic transparent film with fairly mechanical strength can be obtained. The polymers with some electron acceptors, such as(这里有图片19900418-406-1.gif)etc., can form C. T. complexes which show strong UVabsorption bands at a relatively low energy.

Key words: Methyl (β- phenethyl) dichlorosilane, Diphenyldichlorosilane Four membered rings with Si-N bonds, Polysilane