The thiophene derivative with ferricyanide end group and its polymers: synthesis and electrochromic performance

A novel thiophene derivative (Fe–Th) with ferricyanide end group is successfully synthesized. The polythiophene derivative (Fe–PTh) is additionally obtained in aqueous solution by polymerization of Fe–Th, and shows a nanoparticle structure with a diameter from 10 to 100 nm. A simple solid-state electrochromic device is fabricated using the Fe–PTh as electrochromic material, and displays a novel three-color electrochromism from blue, green, and red with the increased potential.