Facile synthesis of naphthodithiophenediimide based small molecules and polymers via direct arylation coupling

Naphthodithiophenediimide (NDTI) as a new electron-accepting building block has been used to synthesize narrow bandgap small molecules and polymers for ambi-polar organic field-effect transistors and organic solar cells. Herein, we report the first application of direct arylation coupling to synthesize a series of NDTI-based small molecules and polymers. The regioselectivity was examined in the direct arylation coupling of NDTI with 2-bromo-9,9-dihexylfluorene. Two NDTI-based narrow bandgap polymers, one with benzothiadiazole and the other with 9,9-dioctylfluorene, were synthesized via direct arylation polymerization. The chemical structures and optoelectronic properties of these molecules and polymers were characterized.