Broadly absorbing bluish black-to-transmissive sky blue electrochromic polymer based on 3,4-dioxythiophene

A novel conjugated polymer PProDOT(MeEO)2 based on dioxythiophene with symmetric double ethoxymethyl pendant groups was successfully synthesized through electrochemical polymerization. The polymer film exhibits reversible electrochromism switching between broadly absorbing bluish black neutral state (− 0.1 V) and transmissive sky blue oxidized state (0.7 V). The symmetric double short-chain ethoxymethyl substitution pattern was utilized to realize the broadly absorbing bluish black neutral state of the polymer film. The electrochemical, spectroelectrochemical, and electrochromic switching properties of the polymer film were studied in detail.