Synthesis, electropolymerization and electrochemical characterization of some new acrylate substituted thiophene derivatives

Abstract

In this work, three new acrylate substituted thiophene monomers, (3-thienyl) methylacrylate, 6-(3-thienyl)methoxy-hexylacrylate and 11-(3-thienyl)methoxy-undecylacrylate were synthesized and electropolymerized. Electrochemical polymerisation by a potential step technique leads to the formation of an electroactive film on a Pt electrode in each case. The polymerization involves evidently only the thiophene ring, as no sign of polyacrylate formation could be detected. The oxidation of each polymer was studied by in situ external reflectance FTIR spectroscopy, which showed several bands assigned to (bi)polaron type charge carriers in the region 1500–1000 cm−1. The evolution of the conductivity was studied in situ by the contact electric resistance technique. The conductivity of poly(3-thienyl methacrylate) was found to be higher in aqueous solutions than in acetonitrile. The surface of poly((3-thienyl) methacrylate) was found to have a granular structure observed for many polythiophenes, as studied by atomic force microscopy (AFM).