Alternative Functionalization of Hydrogen-Bonded Diketopyrrolopyrrole Derivatives

Diketopyrrolopyrrole (DPP) derivatives with thiophene capping rings are widely used as semiconductors in organic electronics. Their optoelectronic properties can be adjusted by adding different electroactive groups or by extending the conjugation of the central core, as well as by regulating their self-assembly through noncovalent interactions. One effective strategy demonstrated to improve the performance and morphology of organic solar cells is incorporating hydrogen-bonding units into DPPs. While the functionalization of the DPP lactams and the coupling of aromatic units to the thiophene rings are the most common procedures to tune the properties of such derivatives, modifying the thiophene capping units with hydrogen-bonding groups is a challenging synthetic task. Despite this difficulty, incorporating amide-containing substituents into the thiophene rings of single core thiophene-capped DPP derivatives could yield exciting results, as the advantages of having hydrogen-bonded & pi;-conjugated systems based on these modified DPPs have not been explored thoroughly. This work reports on an efficient method for synthesizing such derivatives.