Building Block for the Synthesis of Pyrrole Derivatives

π-Conjugated polymer chains consisting of heteroaromatic rings, such as thiophene or pyrrole, have been extensively studied due to their potential application as sensors or electrochromic materials. Shim et al. have reported the synthesis of a pyrrole monomer bearing two adjacent thiophene rings, which was prepared from 1,4-di(2-thienyl)-1,4-butanedione. The polymer film, grown in situ on an electrode by electrochemical polymerization, exhibits a good electrochromic property with a striking color change and a response time, changing from yellow at 0.0 V to blue at 1.0 V in 0.95 second.