Synthesis and polymerization of 3,3′-dialkyl-2,2′-bithiophenes

A series of 3,3′-dialkyl-2,2′-bithiophenes (DAT2s) has been synthesized by the nickel-catalyzed Kumada coupling of 2-bromo-3-alkylthiophene with 2-(3-alkylthienyl) magnesium bromide. These monomers were analyzed by NMR and UV–Vis spectroscopies. The monomers were oxidatively polymerized with iron(III) chloride to yield the respective π-conjugated poly(3,3′-dialkyl-2,2′-bithiophene)s. The new polymers were characterized with 1H NMR and UV–Vis spectroscopies. Conductivity was in the order of 10–102 S/cm, depending upon the length of the alkyl chain.