Structures and charge–discharge properties of spin-carrying ferrocene derivatives

Ferrocene derivatives carrying TEMPO radical exhibited unique battery properties based on redox-active ferrocene and TEMPO units together with inherent magnetic properties. Several ferrocene derivatives (1–6) carrying nitroxide radical were prepared as dual redox compounds. They have distorted molecular structures and exhibit oxidation potentials based on both ferrocene and nitroxide groups except 4. The multi-step charge–discharge processes are discriminated for mono-substituted derivatives with the first discharge capacity up to 400Ahkg−1 for imino-derivative 3, while relatively characterless profiles are observed for bis-substituted derivatives 4 and 6 with capacity over 300Ahkg−1.