Figure 2

STM images of self-assembled structures made of DHPA on Au(111).
(a) Chains meander on Au(111), growing mainly on the herringbone reconstruction pattern and extending over terraces; (b) the chains occasionally branch out and produce Y-junctions, indicated by the white arrows; (c) the chains growing inside the nano pit in areas where the herringbone reconstruction is still present. Scanning conditions: (a) Sample bias U = 1 V, tunneling current I = 50 pA, temperature T = 104 K, (b,c) U = 0.8 V, I = 50 pA, T = 104 K.