Massenspektren organischer Verbindungen. 2. Mitteilung. Cyclohexanone

Abstract

Abstract The mass spectra of cyclohexanone, the mono‐ and dimethylcyclohexanones, 2,4,6‐ and 3,4,5‐trimethylcyclohexanone and their 2,6‐deuterated analogs are presented. In addition 3,5‐d 4 ‐ and 4‐d 2 ‐cyclohexanone, 3,5‐d 4 ‐ and 4‐d 2 ‐2‐methyl‐cyclohexanone and 2‐(d 3 ‐methyl)‐cyclohexanone are synthesized and their mass spectra determined. High resolution techniques and labelling with 18 O are employed to differentiate between oxygen containing fragments and those consisting of C and H only in the spectra of all nondeuterated and some of the deuterated compounds. The fragmentation of these ketones under electron impact is discussed in detail in terms of breakdown mechanisms. Appearance potentials of the principal fragments of cyclohexanone are determined.