Mass spectra of ferrocenophanes. Cyclic peroxide derivatives

The electron impact mass spectra of two 6-membered cyclic peroxides of ferrocenophane depend sensitively on the temperature of the sample heater of the direct inlet system. It is confirmed that their spectra contain some fragment ion peaks arising from thermal decomposition or rearrangement products, but that the ion at m/e (M–28) is due to elimination of ethylene from the molecular ions of the peroxides by a retro Diels-Alder type reaction.