Figure 1

(a),(d) Schematic drawing illustrating the increase in ordered area with maturation time, assuming a nucleation and growth process. At early times, only a few and comparatively small regions of ordered supramolecular monolayers as shown in (b) (size: $43\times 43{\mathrm{nm}}^2$, $V_s=-0.6\mathrm{V}$, $I_t=1.9\mathrm{nA}$, 77 K) were found within a large disordered area. The closely packed arrangement of parallel zippers was oriented at $16\pm 1°$ with respect to the typical $22\times \sqrt{3}$ herringbone reconstruction of the gold surface [18]. After keeping the sample for several months under UHV at room temperature, larger ordered areas were observed as shown in (e) (size: $43\times 43{\mathrm{nm}}^2$, $V_s=+1.4\mathrm{V}$, $I_t=1\mathrm{nA}$, 77 K), combined with a change of the interlocking with the substrate from an angle of 16° to 12° between the zippers and the surface reconstruction. None of the organized domains showed anymore an angle of 16°. At this stage, we have systematically observed boundaries at the junction between two supramolecular domains oriented at $+12°$ and $-12°$ with respect to the underlying straight reconstruction of the gold surface. Our interpretation is schematized in (c) and (f) corresponding to a change of the number of commensurable points of contact between the molecules and the substrate.Reuse & Permissions

Figure 2

(a) STM image of submonolayer deposition ($20\times 20{\mathrm{nm}}^2$, $V_s=-1.7\mathrm{V}$, $I_t=2\mathrm{nA}$, 77 K) showing that the EHUT molecules form long zipper chains. Magnifications of parts of the zippers were selected to visualize the sliding possibilities of single (b) and double (c) EHUT molecules. The zipper chains follow the herringbone surface reconstruction (angle of 0°). The corresponding proposed adsorption model is depicted in (d).Reuse & Permissions

Figure 3

Topographic image ($100\times 100{\mathrm{nm}}^2$, $V_s=-1.7\mathrm{V}$, $I_t=2\mathrm{nA}$, 77 K) of a large supramolecular layer with an angle of 12° with the herringbone reconstruction (dark arrows) and the zippers (white arrow). The supramolecular layer crosses a monoatomic step (about $0.24\pm 0.02\mathrm{nm}$) of the underlying gold substrate. While the $22\times \sqrt{3}$ reconstruction of the Au(111) surface is shifted, the supramolecular layer remained undisturbed, keeping the orientation of the zippers from the upper to the lower terrace of the substrate.Reuse & Permissions

Figure 4

(a) Topographic image of a supramolecular layer after three months of maturation at RT under UHV conditions (a) $100\times 100{\mathrm{nm}}^2$, $V_s=-1.8\mathrm{V}$, $I_t=1\mathrm{nA}$, 77 K. (b) ($21\times 21\mathrm{nm}$) and (c) ($13\times 13\mathrm{nm}$) represent zooms of (a). (d) Schematic representation related to the reordering of EHUT molecules at domain boundaries.Reuse & Permissions