Tri-N-annulated hexarylene: An approach to well-defined graphene nanoribbons with large dipoles

We report a highly efficient synthetic methodology toward tri-N-annulated hexarylenes from easily available N-annulated perylenes, which Is favored by the oxidative ring fusion driven by DDQ/Sc(OTf)₃. To assist the characterization of the new compounds, quantum-chemical calculations of structural and spectroscopic properties have been carried out for three oligomers of N-annulated rylenes, It Is shown that tri-N-annulated hexarylene dyes display remarkably large dipole moments likely associated with the formation of H aggregates, as suggested by the marked concentration dependence of the measured UV-vis spectra. It is suggested that the combination of π-π stacking Interactions and dipole-dipole interactions may favor the formation of highly ordered supramolecular structures, resulting In enhanced charge carrier mobilities.