Picket-fence polythiophene and its diblock copolymers that afford microphase separations comprising a stacked and an isolated polythiophene ensemble.

All-polythiophene diblock copolymers, comprising one unsheathed block and one fenced block, were synthesized through catalyst-transfer polycondensation. The unsheathed block self-assembles through π-π stacking, thereby inducing microphase separation. Consequently, we have succeeded in creating a microphase separation comprising an ensemble of stacked and isolated polythiophenes. This achievement could be extended to various unexplored applications as a result of the integration of the contrasting functions of the two blocks.