Polymers, dimers and radical cations from electrochemical oxidation of interring-bridged thiophene and thiophene-phenylene tetramers.

The electrochemical oxidation of 2,5-thienylene- (T) and 1,4-phenylene- (P) based arylene tetramers T4, TP2T and PT2P, in which the torsion angles between couples of adjacent rings are blocked by a chemical bridge, has been performed in acetonitrile. The products have been characterised by cyclic voltammetry, MALDI mass spectrometry, FT-IR, UV-vis and ESR spectroscopies, and in-situ conductivity and identified as radical cations, dimers or polymers depending on the T-P sequence in the monomer.