Electrochemical Properties of a New Star‐Shaped Pyrrole Monomer and its Electrochromic Applications

Summary: A new monomer, 2,4,6‐tris(4‐(1 H ‐pyrrol‐1‐yl)phenoxy)‐1,3,5‐triazine (Tria‐Py) was synthesized via the reaction of 4‐(1 H ‐pyrrol‐1‐yl)phenol with 2,4,6‐trichloro‐1,3,5‐triazine. It was electrochemically polymerized in a dichloromethane/acetonitrile solvent mixture. The polymer P(Tria‐Py) was characterized via CV, FTIR, SEM and UV ‐vis spectroscopy. Spectroelectrochemical analysis revealed electronic transitions at 346, 508 and 665 nm, revealing π to π * transitions, and polaron and bipolaron band formations respectively. We also made a dual–type, complementary‐colored electrochromic device using P(Tria‐Py)/poly(3,4‐ethylenedioxythiophene) (PEDOT) in a sandwich configuration. The device switches between dark blue and red colors with a switching time of 2.2 s and an optical contrast (% Δ T ) of 25%.Synthesis route for the Tria‐Py monomer.