Concise Syntheses, Polymers, and Properties of 3-Arylthieno[3,2-b]thiophenes

Abstract

Thieno[3,2-b]thiophenes (TT), having para-substituted phenyl groups at C-3, have been synthesized through a ring closure reaction, using P4S10, in moderate to high yields. Their absorbance studies displayed that the TT, having nitrophenyl group had the most red shift absorbance at 365 nm, which also showed the lowest optical band gap of 2.92 eV; the rest of the TTs had the absorbance between 300 and 302 nm. Cyclic voltammetry studies indicated that while all the TTs had the oxidation potentials above 1.0 V, the TT with dimethylaminophenyl group had the lowest oxidation potential of 1.33 V. The rest had the oxidation potentials between 1.6 and 1.99 V. The TTs were both electropolymerized and copolymerized with thiophene through Suzuki coupling reaction. Electropolymerized polymers indicated that while the polymer having strong electron donating dimethylaminophenyl group had the lowest oxidation potential of 0.97 V, the rest of the polymers displayed the potentials between 1.09 and 1.39 V. Their electronic ...