Theoretical treatment of oligopyrrole dimerization

The C2-C2ʹ dimerization of oligopyrrole generated by electrochemical oxidation of the corresponding monomer has been modeled by transition state calculations. The modeling approach takes into account solvent effects and (i) shows that the coupling distance in the transition states decreases with oligomer length, (ii) demonstrates that dimerization rates in the gas phase or in an apolar solvant decrease with oligomer length but that in water they increase with oligomer length, (iii) suggests that in a less solvating medium the dimerization rate evolution with chain length could be reversed.