Broken π-conjugated thiophene systems

A series of 1,3-di(3,3′-dialkyl-2,2′-bithien-5-yl) propanes has been synthesized by the lithiation of 3,3′-dialkyl-2,2′-bithiophenes, followed by substitution with 1,3-dibromopropane. These monomers were analyzed by NMR and UV–Vis spectroscopy. The monomers were oxidatively polymerized with iron(III) chloride to yield the respective broken π-conjugated poly(1,3-di(3,3′-dialkyl-2,2′-bithien-5-yl) propane)s. The new polymers were characterized with ¹ H NMR and UV–Vis spectroscopy. Due to π-stacking of the thiophene segments, these polymers show conductivity on the order of 10 ⁻⁶ S/cm upon doping.