Poly(phenylmethylsilane) obtained by electrochemical reduction in a divided cell containing a polymeric membrane

The electrochemical synthesis of poly(phenylmethylsilane) was carried out i n a divided cell using a polymeric anion-exchange membrane. The solution co ntained phenylmethydichlorosilane (PhMeSiCl2), mixed solvent tetrahydrofura n + hexamethylphosphoramide, with tetrabutylammonium perchlorate as support electrolyte. The electrodes were stainless steel as the cathode, stainless steel as the sacrificial anode or platinum as the resistant anode. Poly(ph enylmethylsilane) was obtained in yields from 1.5 to 4.5 % from phenylmethy ldichlorosilane concentrations equal or higher than 1 M. The number-average molecular mass M, of poly(phenylmethylsilane) was in the range from 5600 t o 9500. A monomodal molecular weight distribution was obtained with a polyd ipersity index of 2. The spectra of H-1, C-13, Si-29 NMR and IR were determ ined. From the 29Si NMR analysis, the poly(phenylmethylsilane) showed a cle ar difference in the tacticity related to the chemical synthesis of the sam e polymer. The UV spectra showed a strong absorption in a 331 to 335 nm cha racteristic for the poly(phenylmethylsilane).