Control of the symmetry of binuclear ferrocene derivative by using chiral substituent and its mixed-valence state

The mixed-valence 1′,1′′′-bis((R)-2-phenylbutyl)-, 1′,1′′′-bis((S)-2-phenylbutyl)- and 1′-((R)-2-phenylbutyl)-1′′′-((S)-2-phenylbutyl)-1,1′′-biferrocenium salts were investigated to reveal the importance of cation symmetry on the mixed-valence states. (R,R) and (S,S) samples never showed the perfect valence detrapping, while (R,S) sample showed the detrapped-valence state at room temperature.