ELECTRON-TRANSFER IN MIXED-VALENCE 1',1'''-BIS(M-BROMOBENZYL)BIFERROCENIUM TRIIODIDE

The solid-state physical properties of the new mixed-valence 1',1'''-bis(m-bromobenzyl)biferrocenium triiodide are reported. Mossbauer spectra of a microcrystalline sample indicated the presence of both delocalized and localized species. In the case of a recrystallized sample, below 200 K there are two doublets in the Fe-57 Mossbauer spectra which, on increasing the temperature, become a single ''average-valence'' doublet at ca. 250 K. The effects of the nature of the motion of charge in counterion and cation-anion interactions on solid-state electron transfer were investigated by studying intramolecular electron transfer for a series of 1',l'''-bis(halobenzyl)biferrocenium salts in solution.