Figure 3: Hierarchical on-surface synthesis of 2D polymers with carbonyl-functionalized pores.

(a) Macrocycles and chains formed after the first reaction step at 420 K (deposition at 365 K). The remaining bromine atoms at the corners can be clearly identified in the STM images. (b,c) Covalently linked honeycomb network formed after the second reaction step at 540 K. (d,e) Corresponding DFT structures of the CTPA network on the Au(111) surface. STM parameters: (a) I=100 pA, V=−80 mV, inset: I=800 pA, V=−80 mV; (b) I=50 pA, V=−1 V; (c) I=400 pA, V=−50 mV.