Electrochemical, spectral and theoretical studies of two new methyl-thieno[3,2-b]benzothiophenes and their polymers electrosynthesized in organic and micellar media

Electrosynthesis of poly(2-methyl-thieno[3,2-b]benzothiophene) [poly(2-MeTBT)] and poly(3-methyl-thieno[3,2-b]benzothiophene) [poly(3-MeTBT)], was performed by anodic oxidation of 2-MeTBT and 3-MeTBT on Pt electrode in 0.1 M LiClO4 acetonitrile solution and in a partially aqueous micellar medium (water/methanol, 9/91, v/v) containing 0.39 M perchloric acid and 0.1 M SDS (sodium dodecylsulfate). The electrochemical characteristics and FT-IR spectra of 2-MeTBT and 3-MeTBT, as well as their optical properties were studied. The corresponding polymers were investigated by cyclic voltammetry, MALDI-TOF, FT-IR, electronic absorption and fluorescence spectroscopy. A theoretical approach based on molecular orbital (MO) calculations and using a radical-cation electropolymerisation mechanism, was proposed for the oligomer structural characterization.