Structure and thermochemistry of β-silicon carbenium ions in the gas phase

Abstract

Both protonation of trimethylvinylsilane and addition of Me₃Si⁺ to ethylene in the gas phase produce the cation Me₃Si(CH₂CH₂)⁺, with 39 kcal mol^–1 stabilization energy relative to ethyl cation; however, chloride abstraction from Me₃SiCHClCH₃ yields a mixture of ions resulting from competing methyl and hydrogen shifts in the nascent silylcarbenium ion.