Synthesis and characterization of novel regioregular polythiophenes

Three novel regioregular polythiophenes with side chain substituents resulting in increased oxidation potentials relative to poly(3-dodecylthiophene) have been synthesized using the McCullough polymerization protocol. All polymers have >95% head-to-tail couplings as evidenced from ¹H-NMR and are furthermore characterized by SEC, solution and solid-state UV-vis spectroscopy, and cyclic voltammetry. By varying the nature of the side chains the redox properties could be altered: the first oxidation potentials vary between 0.75 V and 1.25 V and the first reduction potentials between -1.40 V and -1.85 V. The optical properties of the polymers in solution and as thin solid films were much less affected by the different substituents.