FUNCTIONAL POLYSILANES .4. DUPLICATION BY REDUCTION OF CHLOROSILANES BY LITHIUM FOR THE SYNTHESIS OF MEGA-BIS(TRIMETHYLSILYL)OLIGO(METHYLPHENYLSILANE)S - PARASITE SILYLATION REACTIONS OF PHENYL NUCLEI

The coupling of dichloromethylphenylsilane (1) with chlorotrimethylsil ane (2) by lithium is considered for the synthesis of low-molecular-we ight organosilane polymers 3 and for the preparation of heptamethylphe nyl-2-trisilane (3 a) and octamethyldiphenyl-2,3-tetrasilane (3 b). Si ze-exclusion chromatography, ultraviolet and infrared spectroscopies a nd nuclear magnetic resonance (H-1, C-13 and Si-29 NMR) analyses of th e crude product 3 were performed and compared with those of 3 a and 3 b. According to the spectroscopic characteristics of rimethylsilyl)-3, 4,5,6-cyclohex-1-enyl-2-trisilane (4), and the observed silylation of the trisilane 3 a when it is submitted to the action of a (CH3)(3)SiCl /Li/tetrahydrofuran system, the silylation of the phenyl ring during t he reductive condensation of the chlorosilanes is supported by NMR ide ntification of 4-like structures.