An oligothiophene cation radical that forms π‐stacks: A model for polaron aggregation in conducting polymers

A new class of functional units for preparing charge transfer salts, based on π‐stacks of a conducting oligomer in analogy to the well‐known stacks of TTF units, is reported and provides a connection between CT salts and conducting polymers. The synthesis of the new water‐soluble thiophene oligomer is presented and it is suggested that π‐stacks may be present in some oxidized polythiophenes and similar polymers.