Electrochemical Studies of Ferrocene and Ferrocenium Ion in Aluminum Chloride-N-1-Butylpyridinium Chloride Ionic Liquid

摘要

Electrochemical studies of the ferrocene/ferrocenium ion system have been carried out in AlCl3-N-1-butylpyridinium chloride ionic liquid at 40 C as a function of melt composition. The ferrocene/ferrocenium electron-transfer process is reversible, and the formal potential of the ferrocene/ferrocenium cation couple varies only slightly with wide changes of solvent acidity. Ferrocene and ferrocenium ion are both stable in neutral butylpyridium tetrachloroaluminate. In basic (excess BuPyCl) melts ferrocene is stable, while the ferrocenium cation is decomposed by Cl(-) to Fe(Cp)2 and FeCl4. In acidic (excess AlCl3) melts ferrocene is oxidized to ferrocenium ion by traces of oxygen and reacts with products of the reaction of water with the solvent. The ferrocenium cation is stable in the acid melts.