Mass-spectral study of 9-[α(β,γ)-picolylidene]-1(4)-azafluorenes

A mass-spectral study was carried out on the behavior of the Z- and E-isomers of 9-picolylideneazafluorenes. A possible mechanism for the elimination of a hydrogen atom from the M+ ion of the Z- and E-isomers of 1(4)-azafluorene derivatives was examined. Mass spectrometry permitted a distinction between compounds isomeric relative to the position of the nitrogen atom in the azafluorene fragments and also the Z- and E-isomers of picolylidene derivatives of 1- and 4-azafluorenes possessing β-and γ-pyridyl substituents.