O-Alkylated Nitroalkane Cations in the Gas Phase: Selective Preparation of C_3H_8NO_2~ + Isomers and Elucidation of their Unimolecular Chemistry

摘要

Extending studies of hydrogen atom adducts to nitromethane [1] and nitrobenzene [2], alkyl radical adducts to nitro compounds are being investigated in our laboratory. Previously, a methyl cation adduct to nitromethane was found in nitromethane-CI plasma [3,4]. A SIFT MS study showed that this adduct is formed by the reaction of nitromethane radical cation with another molecule of nitromethane, and based on its CAD mass spectra, a structure of O-methylated nitromethane, MeNO2Me+, was assigned to this cation [5]. In the course of studies focused on the mechanism of formation and unimolecular fragmentation of this cation, an alternative methods of its preparation applicable to a conventional CI ion source were sought that would allow for selective isotope labeling of methyl groups in MeNO2Me+, as well as for addition of larger alkyls.