摘要
On-surface synthesis has emerged as a powerful strategy to fabricate unprecedented forms of atomically precise graphene nanoribbons(GNRs).However,the on-surface synthesis of zigzag GNRs(ZGNR)has met with only limited success.Herein,we report the synthesis and on-surface reactions of 2,7-dibromo-9,9′-bianthryl as the precursor towardπ-extended ZGNRs.Characterization by scanning tunneling microscopy and high-resolution noncontact atomic force microscopy clearly demonstrated the formation of anthracene-fused ZGNRs.Unique skeletal rearrangements were also observed,which could be explained by intramolecular Diels-Alder cycloaddition.Theoretical calculations of the electronic properties of the anthracene-fused ZGNRs revealed spin-polarized edge-states and a narrow bandgap of 0.20 eV.
基金
This work was supported by the Swiss National Science Foundation(Grant No.200020_212875)
the NCCR MAR-VEL funded by the Swiss National Science Foundation(Grant No.205602)
the Werner Siemens Foundation,the Max Planck Society,and the Okinawa Institute of Science and Technology Graduate University.K.M.acknowledges a fellowship from Gutenberg Research College,Johannes Gutenberg University Mainz.Computational support from the Swiss Supercomputing Center(CSCS)under project ID s1141 is gratefully acknowl-edged.We acknowledge PRACE for awarding access to the Fenix Infrastructure resources at CSCS,which are partially funded by the European Union’s Horizon 2020 research and innovation program through the ICEI project under grant agreement No.800858.Technical support from Lukas Rotach is gratefully acknowledged.
