Tailoring receptors to semiconducting polymers: Preparation and optical characterization

New Thiophene based polymers: poly-6,6′-(2-thienyl)-2,2′-bipyridine (p-262-bT-bPy), and poly-6,6′-(3-thienyl)-2,2′-bipyridine (p-362-bT-bPy) were synthesized and characterized. The measured photoinduced absorption spectrum of p-262-bT-bPy consists of several broad bands peaked at 0.55 eV, 1.1 eV and 1.9 eV. Due to the shape of these bands and the presence of photoinduced phonons (IRAV), the mainly photoexcited species are assigned to polarons, bipolarons and a triplet exciton. An electroluminescent device where the active element is p-262-bT-bPy was prepared. In contrast to (p-262-bT-bPy), p-362-bT-bPy exhibit photophysical properties resembling nonfunctionalized polythiophene systems. Here, the bipyridine subunits are believed to act simply as cross links between the polythiophene chains.