Rigid oligomers based on the combination of 3,6-dimethoxythieno[3,2-b]thiophene and 3,4-ethylenedioxythiophene

New oligomers based on the combination of the 3,6-dimethoxythieno[3,2-b]thiophene and 3,4-ethylenedioxythiophene (EDOT) moieties have been prepared and studied by UV–vis spectroscopy and cyclic voltammetry. The use of the intrinsically rigid thienothiophene units in addition to the S⋯O intramolecular interactions leads to planar conformation of the conjugated chains. While the radical cations of oligomers end capped by n-hexyl chains show a tendency to the dimerization, those substituted by n-hexylsulfanyl chains present a high stability.