Phase Transition in 1′, 1′″-Dihexylbiferrocenium Triiodide Accompanied by a Change In Mixed-Valence State

Abstract

Two different crystals of 1′, 1′″-dihexylbiferrocenium triiodide were obtained from the different solution (hexane or dichloromethane). The salt prepared from hexane has a longer interlayer distance and gives trapped-valence state of Fe atoms, while the salt recrystallized from dichloromethane has a shorter interlayer distance and gives typical fusion-type valence detrapping of the mixed- valence state on the ⁵⁷Fe Mössbauer spectroscopy. By annealed at 323 K the latter changes into the former salt. The X-ray diffraction study of the latter supports the results of the ⁵⁷Fe Mössbauer spectroscopy.