Electrochemical and optical properties of poly(4-(4-(1H-pyrrol-1-yl)phenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole

A novel dithieno[3,2-b:2',3'-d]pyrrole (DTP) derivative, namely, 4-(4-(1H-pyrrol-1-yl)phenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole (DTP-Ph-Pyr) was synthesized, and its corresponding polymer (P(DTP-Ph-Pyr)) was successfully obtained via electrochemical polymerization. Electrochemical and optical properties of this novel polymer were discussed in detail. It was found that the polymer film also exhibited a reversible electrochromic behavior (orange color in the neutral state and blue color in the oxidized state) with a high optical contrast (52.5% at 950 nm) and coloration efficiency (123 cm²/C at 950 nm). Moreover, the electrochemical and optical properties of the polymer were compared with both its electrochromic P(DTP) analogues and its sister polymer structure, poly(1-(4-(1H-pyrrol-1-yl)phenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole) (P(SNS-Ph-Pyr)), possessing same subunit.