N-Acyldithieno[3,2-b:2′,3′-d]pyrroles: Second Generation Dithieno[3,2-b:2′,3′-d]pyrrole Building Blocks with Stabilized Energy Levels

A new class of dithieno[3,2-b:2',3'-d]pyrroles (DTPs) incorporating N-acyl groups have been prepared from 3-bromothiophene via copper-catalyzed amidation. The utilization of various electron-withdrawing acyl groups has allowed stabilization of the HOMO and LUMO energy levels of these popular building blocks for conjugated materials. The synthesis and characterization of this new class of compounds is described, including electrochemical and photophysical data for all compounds and X-ray structural data for the octanoyl, benzoyl, and cyclohexanoyl functionalized compounds. Initial polymers generated via electropolymerization are also reported.