2003 年 51 巻 2 号 p. 365-367
Unimolecular metastable ion decompositions of acetyltrimethyl silane, CH3COSi(CH3)3 (MW: 116, (1)) generated by electron ionization, have been investigated by use of mass-analyzed ion kinetic energy (MIKE) spectrometry and D-labeling. In the metastable time window, the molecular ions 1+ • decompose exclusively into the ions at m/z 101, [M-CH3]+. A considerable extent of H/D exchange occurs prior to this [M-CH3]+ formation. However, the H/D exchange is hardly observed for the [M-CH3]+ formation in the ion source. The generated m/z 101 ions from 1+ • consist of two isomeric ions. A trimethylsilyl ion, (CH3)3Si+, at m/z 73 is generated by at least three different routes.