Preparation of 4,4 '-bis(triphenylamine) viologen and properties of solid-state electrochromic devices

A new electrochromic compound 4,4 '-bis(triphenylamine) viologen was synthesized and its structure was characterized by NMR, IR and MS. Cyclic voltammograms testified that the presence of a couple of redox peaks could show significant electrochromic properties. A uniform electrochromic film was obtained by dissolving the compound in the chloroform and then coating it on ITO glass. A solid electrochromic device(ECD) was pro-duced by using this electrochromic film and electrolyte film. The study of the ECD performance showed that the color of the device has reversible changes from colorless to blue under the change of voltage from-0.8 to 0.8 V. Additionally, the colored state of the ECD can maintain more than five hours without encapsulation, which shows its excellent stability for applications.