Magnetic Hyperfine Mössbauer Spectra of Ferrocenyaldimines-FeCl3 Adducts

Ferrocenylaldimines (Fc-CH=N-R) were prepared by condensation of Schiff base of formylferrocene with polyacenylamines RNH₂; R = naphthyl, anthracenyl and pyrenyl groups. This step was followed by oxidation with FeCl₃ to give [Fc-CH=NR]-FeCl₃ adducts. The electronic state of iron in these adducts was investigated by means of ⁵⁷Fe Mössbauer spectra except for [Fc-CH=N-Pyr]-FeCl₃ showed that only a doublet was observed at ambient temperature. As the temperature was decreased below 200 K, additional magnetic hyperfine splitting was observed characteristic of ferric oxide.