Conducting Thiophene-Annulated Azepine Polymers

We report the synthesis of annulated azepines, conjugated seven-membered ring systems with nitrogen, designed to undergo an electrochemically controlled bent-to-planar transformation driven by aromatization. A Pd-catalyzed double amination strategy enabled us to synthesize annulated azepines, which are thermally and electrochemically stable even in highly oxidized states. Several methods of chemical and electrochemical polymerization yielded azepine-based materials that were demonstrated to retain their redox properties in the solid state under ambient conditions. Because of their redox stability and conductivity, these polymers could find utility in actuating materials research.