Electron‐impact studies—LIV: The formation of [C13H9]+ in the mass spectra of benzyl phenyl ketoxime and 2,3‐diphenyl‐2‐H‐azirine

The formation of m/e 165 in the spectrum of benzyl phenyl ketoxime involves the intermediacy of a rearranged 2,3‐diphenyl‐2‐H‐azirine radical ion. 2H and 13C labelling of the ketoxime together with 2H labelling of the azirine has allowed certain proposals to be made concerning the complex processes producing m/e 165 in both spectra. The mode of formation of m/e 167 in the spectrum of benzyl phenyl ketoxime has also been studied.