Broken π-conjugated thiophene systems: 3. Synthesis and polymerization of 2,2-di(alkylthien-2-yl)propanes

A series of 2,2-di(alkylthien-2-yl)propanes has been synthesized by chloroalkylation of the thiophene ring in the presence of zinc chloride. The products were obtaines as mixtures of regio isomers which were not separated. These monomers were oxidatively polymerized with iron(III) chloride to yield the respective broken π-conjugated poly(2,2-di(alkylthien-2-yl)propane)s. The new polymers are broken π-conjugated due to the blocking of the bridge carbon with two methyl groups. Due to the limited conjugated segments, these polymers show conductivity on the order of 10−7 S/cm.