Electron impact studies. LXXVIII. Rearrangement ions and proximity effects in the 'doubly charged ion' mass spectra of benzoic acid derivatives

Abstract

The technique of Beynon1,2 has been used to determine the ?doubly charged ion? mass spectra of a series of benzoic acid derivatives. A general feature of all spectra is the presence of pronounced M-CO species. The losses of carbon monoxide from the doubly charged molecular ions of m- amino- and m-hydroxy-benzoic acids originate mainly from the carboxyl groups, whereas the predominant loss from benzoic acid involves the aryl ring system. The spectra of anthranilates and salicylates contain peaks produced by characteristic proximity effects.