Unstable intermediates. Part LXXXI. Electron spin resonance spectra of γ-irradiated methyl silanes: methyl silyl radicals

Abstract

The major radical products on exposure of various methyl silanes to ⁶⁰Co γ-rays are the corresponding silyl radicals formed by rupture of Si–H bonds. The ²⁹Si hyperfine tensors show that these radicals are pyramidal, with 3p to 3s ratios of ca. 5·7. It is shown that the mean R–Si–R angles are almost unaffected on replacement of hydrogen by methyl. Radiolysis of Me₃SiCl at 77 K probably also gave Me₃Si radicals, together with methyl radicals and a species thought to be Me₂SiCl. The results are compared with those for other σ-radicals of this type.