The mass spectra of the negative and positive ions of the methyl esters of the fluorine-substituted benzoic acids

1. A study has been made of dissociative electron capture by the molecules of the methyl esters of substituted benzoic acids with fluorine-containing alkyl substituents. Mass spectra of the positive ions of these compounds have been obtained. 2. The principal decomposition paths for the positive and negative molecular ions of these compounds have been established. Conjugation of the perfluoroalkyl and carbomethoxy groups through the benzene ring has a marked effect on dissociative electron capture. 3. The mass spectra of the negative ions are more sensitive to alteration of the molecular structure than are the mass spectra of the positive ions.