Evaluating ferrocene ions and all-ferrocene salts for electrochemical applications

This report presents four “all-ferrocene” salts comprised of ferrocene anions and cations and evaluates their solubility and electrochemical properties. The four salts are formed via metathesis reactions employing the (ferrocenemethyl)trimethylammonium cation and mono and bis sulfonate or carboxylate ferrocene anions. We observed that the potentials of the ferrocene components was not only dependent on the substituent, but also on the solvent medium. In particular, the sulfonate and carboxylate ferrocene anions exhibited significant shifts in redox potential between water, propylene carbonate (PC), and DMF. Most notably, in (ferrocenemethyl)trimethylammonium 1,1′-bis(sulfonato)ferrocene, the potentials of the cation and anion reverse, with the anion having a lower potential in aqueous solution and a more positive potential in organic media.Graphical abstractFerrocene materials are being heavily investigated as possible redox flow battery (RFB) components. Herein, we present a series of four new “all-ferrocene” salts and evaluate their electrochemical behavior. The choice of solvent and the combination of ions in the salt greatly affects the observed redox potentials.
Source: Journal of Organometallic Chemistry - Category: Chemistry Source Type: research