Metallo-Supramolecular Polymers Made of Cobalt and 3,4-Propylenedioxythiophene-Bisterpyridine Complexes for Electrochromic Applications

In this study, a series of organometallic hybrid polymers were synthesized through the complexation of cobalt metal ions with bisterpyridine derivatives bearing substituted 3,4-propylenedioxythiophene. The prepared polymers exhibited specific color changes from orange to dark green based on the metal-to-ligand charge transfer transitions. Cyclic voltammograms of the polymers showed a reversible redox wave according to the redox reaction of the cobalt metal ions. In addition, the electrochromic devices containing the polymer film cast on an indium-tin-oxide electrode exhibited good electrochromic properties, with reversible and stable spectral transitions of the cobalt-bisterpyridine complexes.