NEW POLYCARBOSILANE MODELS .1. POLY[(METHYLCHLOROSILYLENE)METHYLENE], A NOVEL, FUNCTIONAL POLYCARBOSILANE

The aluminium trichloride catalyzed interchange of methyl and chlorine on silicon has been applied for the first time to the polycarbosilane series. Thus, poly left bracket (dimethylsilylene)methylene right bracket has been converted into a poly left bracket (methylsilylene)methylene right bracket the first functional polycarbosilane possessing an unambiguous linear skeleton. The considerable lowering of the average molecular weight, a consequence of the backbone cleavage, was accompanied by the formation of dimethylchlorosilyl groups as the chain terminals. These were characterized by **1H, **1**3C, and **2**9Si NMR.