Synthesis and electrochromic properties of benzonitriles with various chemical structures

In this study, the electrochromic behavior of benzonitrile compounds were investigated. For this, a series of benzonitrile compounds with different chemical structures were synthesized and their electrochemical properties were investigated by cyclic voltammetry. Electrochromic behavior of the benzonitrile derivatives were also investigated by constructing sandwich type electrochromic devices and recording the changes in the UV–vis spectra as a function of applied potential. The compounds exhibited excellent electrochromic properties such as a high optical contrast, low driving voltage, good switching stability, high coloration efficiency, and a fast response time. All five compounds had different colors (orange, yellow-green, reddish-brown, green, blue) and driving voltages that were highly dependent on their chemical structures. The results indicate that benzonitriles are good electrochromic materials and should be of interest for applications such as electrochromic smart windows, information displays, and optical storage devices.