Electron impact studies. LXXIX. Negative-ion mass spectrometry of functional groups, 2-Aryl-1,3-oxathians and 1,3-Dioxans

Abstract

A general summary of the formation of negative ions is given. The negative-ion mass spectra of 2-aryl-1,3-oxathians contain pronounced molecular anions together with fragment ions produced by both simple and complex cleavage processes. Evidence is presented which suggests that the decomposing molecular anions have low internal energies. The spectra of nitroaryloxathians contain further examples of specific hydrogen scrambling in negative ions, and that of the o-nitro derivative exhibits a characteristic proximity effect. In contrast, the isomeric nitrophenyl-1,3-dioxans give similar spectra and show neither hydrogen scrambling nor proximity effects.