Electrochemical Properties of Polyimides and Related Imide Compounds

Polyimides can undergo reversible electrochemical reduction/oxidation reactions. The electroactive centers have been identified as involving the aromatic‐carbonyl π‐system of the imide functional groups. The aromatic structure and substitution on the imide moiety affects the redox potentials. The reduced (radical‐anion and dianion) forms are stable and have strong absorbances in the visible spectral region. The degree of electronic transmission through the imide nitrogen for one‐ and two‐electron reductions has been investigated using a Hammett (σ) correlation. Delocalization of excess electron density in reduced imides has been studied using FTIR and UV‐Vis spectroscopy.