Mass spectrometric study of 4-azafluorenes

The dissociative ionization of 4-azafluorene and its methyl and phenyl derivatives was investigated. The relative intensity of the [M - CH3]+ ion peak depends on the position of the CH3 group in the 4-azafluorene ring. It was established that the loss of an RCN particle (R=H, CH3, and C6H5) for unsubstituted 4-azafluorene takes place from the M+ and [M - H]+ ion, exclusively from the [M - H]+ ion for the methyl-substituted compounds, and from the [M - H]+ and [H - 2H]+ fragments for the phenyl-substituted derivatives. Randomization of the deuterium ions in the 9,9′-d2-4-azafluorene molecular ion was observed. © 1978 Plenum Publishing Corporation.