Synthesis, electrochemical and electrochromic properties of novel 2,4,6-Tri(pyridine-4-yl)pyridilium derivatives

Abstract

Four star-shaped like fused heterocyclic compounds multi-electrochromic materials 2,4,6-Tri(pyridine-4-yl)pyridilium derivatives (TPPDs) were successfully synthesized and characterized by NMR, Solid IR spectra, APCI-MS, and UV–vis spectroscopy. 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 these compounds were fabricated with an active area of 3cm×4cm and their electrochromic performances were further studied. It was found the ECDs presented a stable as well as multicolor electrochromic change from colorless to blue, then violet-blue and finally black-blue between 0V and +4.0V. In addition, the prepared electrochromic materials had high coloration efficiency, low switching time, and nice redox stability. This type of multi-electrochromic materials would thus be promising candidates for applications in electrochromic devices.