Chemical ionization mass spectra of chlorine-substituted aryl-propio- and -butyro-nitriles: Occurrence of an unusual radical-induced cyclization process

The chemical ionization (CI) induced reactions in certain chlorine-containing aryl-substituted alkyl nitriles have been studied using different reagent gases including ND₃ and CD₄ and with the help of collisional activation spectra. A few fragmentations can be explained only on the basis of protonation of or electrophilic attachment to neutral products formed in the CI source. A detailed investigation of the unusual dehalogenation and dehydrohalogenation reactions occurring in some of these molecules has shown that radical-induced cyclization processes give rise to these ions.