Mixed π-conjugated oligomers of thiophene and 3,4-ethylenedioxythiophene (EDOT)

Conjugated oligomers based on various combinations of thiophene and 3,4-ethylenedioxythiophene (EDOT) moieties have been synthesised. Comparison of the optical and electrochemical properties shows that the introduction of a bis-EDOT core in the middle of the system produces a decrease of the HOMO–LUMO gap which is attributed to an enhancement of the planarity and rigidity of the π-conjugated system.