Purely Armchair or Partially Chiral: Noncontact Atomic Force Microscopy Characterization of Dibromo-Bianthryl-Based Graphene Nanoribbons Grown on Cu(111)

ACS Nano. 2016 Aug 23;10(8):8006-11. doi: 10.1021/acsnano.6b04025. Epub 2016 Jul 22.

Abstract

We report on the atomic structure of graphene nanoribbons (GNRs) formed via on-surface synthesis from 10,10'-dibromo-9,9'-bianthryl (DBBA) precursors on Cu(111). By means of ultrahigh vacuum noncontact atomic force microscopy with CO-functionalized tips we unveil the chiral nature of the so-formed GNRs, a structure that has been under considerable debate. Furthermore, we prove that-in this particular case-the coupling selectivity usually introduced by halogen substitution is overruled by the structural and catalytic properties of the substrate. Specifically, we show that identical chiral GNRs are obtained from 9,9'-bianthryl, the unsubstituted sister molecule of DBBA.

Keywords: armchair; bottom-up; chiral; functionalized tip; graphene nanoribbons; on-surface synthesis.

Publication types

  • Research Support, Non-U.S. Gov't