Mercury-sensitized photolysis of Me₂SiH₂ The disproportionation reactions of the Me₂SiH radical

Abstract

Mercury-sensitized photolysis of Me₂SiH₂ yields in the primary step an Me₂HSi radical and an H atom with a quantum yield of one. The Me₂HSi radicals undergo a combination reaction [k(2)] as well as two kinds of disproportionation reactions leading to dimethylsilylene [k(3)] and 1-methylsilaethene [k(4)]. The following branching ratios have been determined: k(3)/[k(2)+k(3)+k(4)]=0.64 ±0.10 and k(4)/[k(2)+k(3)+k(4)]⩾0.007. For Me₃Si radicals the branching ratio for disproportionation was also determined and a value of 0.063 was obtained.

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