Synthesis, electrochemical and electrochromic properties of novel pyridinium salts based on 2,6-di(4-pyridyl)-4-benzylpyridilium

Four electrochromic materials 2,6-di(4-pyridyl)-4-benzylpyridilium derivatives (DPBPDs) were synthesized and characterized. The electrochemical properties, electrochromic behavior, electro-optical properties and electrochromic mechanism were investigated by thermogravimetric analysis, cyclic voltammetry and UV–vis absorption spectra. Electrochromic devices based on DPBPDs were fabricated and their electrochromic performances were further studied. It was found the ECDs shows high outstanding optical contrast and reasonable transparency, with color changes from colorless to green during the potential ranges from 0 V (in the oxidized state) to ±2.4 V (in the reduced state). In addition, the prepared electrochromic materials had high coloration efficiency, fast switching time and nice redox stability.