γ-Induced generation of dimethylsilylene from dodecamethylcyclohexasilane

Abstract

γ-Irradiation of dodecamethylcyclohexasilane (I) generates dimethylsilylene in 65% yield when benzene is used as a solvent. Kinetic studies using anthracene as quencher are consistent with a mechanism proposed for the generation of dimethylsilylene. Benzene is first excited by γ-rays and energy is transferred to (I). Excited (I) decomposes to give dimethylsilylene presumably in a way similar to (I) excited by u.v. light. The ratio of the rate constant for self-deactivation of benzene to that for energy transfer from benzene to (I), k₂/k₃, is 5.1 × 10^–2 mol I^–1 at room temperature. Energy transfer to (I) is hindered by added anthracene. The ratio of the rate constant for energy transfer to anthracene to that for energy transfer to (I), k₆/k_3′ is ca. 6 at room temperature. A similar energy transfer is possible in the case of u.v. irradiation.