• 文献标题:   Stabilizing Edge Fluorination in Graphene Nanoribbons
  • 文献类型:   Article
  • 作  者:   PANIGHEL M, QUIROGA S, BRANDIMARTE P, MORENO C, GARCIALEKUE A, VILASVARELA M, REY D, SAUTHIER G, CEBALLOS G, PENA D, MUGARZA A
  • 作者关键词:   graphene nanoribbon, onsurface synthesi, edge functionalization, fluorination, scanning tunneling microscopy, density functional theory, selfassembly
  • 出版物名称:   ACS NANO
  • ISSN:   1936-0851 EI 1936-086X
  • 通讯作者地址:   Catalan Inst Nanosci Nanotechnol ICN2
  • 被引频次:   1
  • DOI:   10.1021/acsnano.0c01837
  • 出版年:   2020

▎ 摘  要

The on-surface synthesis of edge-functionalized graphene nanoribbons (GNRs) is challenged by the stability of the functional groups throughout the thermal reaction steps of the synthetic pathway. Edge fluorination is a particularly critical case in which the interaction with the catalytic substrate and intermediate products can induce the complete cleavage of the otherwise strong C-F bonds before the formation of the GNR. Here, we demonstrate how a rational design of the precursor can stabilize the functional group, enabling the synthesis of edge-fluorinated GNRs. The survival of the functionalization is demonstrated by tracking the structural and chemical transformations occurring at each reaction step with complementary X-ray photoelectron spectroscopy and scanning tunneling microscopy measurements. In contrast to previous attempts, we find that the C-F bond survives the cyclodehydrogenation of the intermediate polymers, leaving a thermal window where GNRs withhold more than 80% of the fluorine atoms. We attribute this enhanced stability of the C-F bond to the particular structure of our precursor, which prevents the cleavage of the C-F bond by avoiding interaction with the residual hydrogen originated in the cyclodehydrogenation. This structural protection of the linking bond could be implemented in the synthesis of other sp(2)-functionalized GNRs.