Organosilicon chemistry. Part VIII. 2-(Pentafluorophenyl)ethylsilyl compounds and related polymers

Abstract

Methyldichlorosilane reacts with hexafluorobenzene under photochemical conditions to give methyl(pentafluorophenyl)chlorofluorosilane, which is readily converted into the corresponding difluorosilane. Silanes (R₃SiH) add to pentafluorostyrene in the presence of hexachloroplatinic acid to give derivatives of 2-(pentafluorophenyl)ethylsilane, C₆F₅·CH₂·CH₂·SiR₃(R₃= Me₃, MeCl₂, or Cl₃). The chlorosilanes (R₃= MeCl₂ or Cl₃) are readily converted into oligomeric siloxanes, but high molecular weight polymers are not easily produced. The polymers with pendant 2-(pentafluorophenyl)ethyl groups are comparable in thermal stability with those which contain pendant 3,3,3-trifluoropropyl groups, and they are not affected by 5% aqueous hydrochloric acid or 5% aqueous sodium hydroxide under reflux.