Fig. 3: Theoretical modeling of a dimer on Au(111).
From: Polycyclic aromatic chains on metals and insulating layers by repetitive [3+2] cycloadditions
(a) Top and (b) side views of the DFT-relaxed geometry of a dimer (as shown in Fig. 2h). One of the carbon atoms adjacent to the N-atom of the phenanthridinium moiety has two hydrogen atoms, pointing upwards and downwards, respectively. Furthermore, one of the phenyl rings of the right monomer (marked with red arrows in a–c) is bending upwards due to steric repulsions between the monomer units. c The simulated AFM image of the dimer shows a bright (more repulsive) contrast for the protruding hydrogen atom and the upwards-bending phenyl ring, in agreement with the contrast observed in the experimental image (Fig. 2e).
