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

In this work, three new acrylate substituted thiophene monomers, (3-thienyl ) methylacrylate, 6-(3-thienyl)methoxy-hexylacrylate and 11-(3-thienyl)meth oxy-undecylacrylate were synthesized and electropolymerized. Electrochemica l polymerisation by a potential step technique leads to the formation of an electroactive film on a Pt electrode in each case. The polymerization invo lves evidently only the thiophene ring, as no sign of polyacrylate formatio n could be detected. The oxidation of each polymer was studied by in situ e xternal reflectance FTIR spectroscopy, which showed several bands assigned to (bi)polaron type charge carriers in the region 1500-1000 cm(-1). The evo lution of the conductivity was studied in situ by the contact electric resi stance technique. The conductivity of poly(3-thienyl methacrylate) was foun d to be higher in aqueous solutions than in acetonitrile. The surface of po ly((3-thienyl) methacrylate) was found to have a granular structure observe d for many polythiophenes, as studied by atomic force microscopy (AFM). (C) 1999 Elsevier Science S.A. All rights reserved.