title: Tri-N-annulated hexarylene: an approach to well-defined graphene nanoribbons with large dipoles.
abstract: 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 pi-pi stacking interactions and dipole-dipole interactions may favor the formation of highly ordered supramolecular structures, resulting in enhanced charge carrier mobilities.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.forename: Simone
authors.initials: S
authors.lastname: Di Motta
authors.forename: Fabrizia
authors.initials: F
authors.lastname: Negri
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Wang