New p-n diblock and triblock oligomers: effective tuning of HOMO/LUMO energy levels

A new series of oligomers consisting of thiophene as p-type unit and oxadiazole as n-type unit were synthesized, and their photophysical and electrochemical properties were evaluated. Cyclic voltammography studies demonstrated that the electronic properties of the p-n diblock oligomers could be modulated by changing the number of thiophene and oxadiazole rings. The molecular regiochemical effect to the electrochemical and optical properties was also investigated.

Changing the number of thiophene and oxadiazole units can modulate redox behavior and emission wavelength of the diblock oligomers. Furthermore, the electronic properties can also be significantly modulated by changing the molecular regiochemistry.