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/k3′ is ca. 6 at room temperature. A similar energy transfer is possible in the case of u.v. irradiation.