Electrosyntheses of anthracene clicked poly(thienylpyrrole)s and investigation of their electrochromic properties

Abstract

A new anthracene containing thienylpyrrole derivative (SNS-Anth) was synthesized through click reaction of 9-((prop-2-yn-1-yloxy)methyl)anthracene with 1-(2-azidoethyl)-2,5-di(thiophen-2-yl)-1H-pyrrole(SNS-N3). The chemical structure of SNS-Anth was confirmed by using 1H, 13C NMR, FT-IR, UV–Vis, Fluoresence and mass spectroscopy techniques. SNS-Anth was subjected to electrochemical polymerization and the resultant polymer (PSNS-Anth) displayed green to blue coloration in 1.40 s with a coloration efficiency of 78 cm2 C−1. The electrochemical copolymerization of SNS-Anth and 3,4-ethylenedioxythiophene (EDOT) was successfully achieved. The copolymer revealed distinct multichromic behavior where a wide pallet of esthetically pleasing colors (pinkish-red, orange, yellow, green and blue) was observed at various potentials. The objective evaluation of the colors of both PSNS-Anth and the copolymer at various potentials was performed through colorimetry studies on the basis of “Commission Internationale de l′Eclairage” (CIE) standards. The response time, optical contrast and coloration efficiency of the copolymer were calculated as 0.67 s, 28.88%, 193 cm2 C−1 (at 900 nm), respectively. Considering the explicit spectral difference between PSNS-Anth and the copolymer, enhancement of the color pallet, switching time, optical contrast safely confirms formation of a true copolymer.