Fig. 2: Chemical structure characterization of products via trimerization of precursors with alkynes terminals.

a Possible on-surface reactions for the main products. b Overview STM image after annealing precursor on Au(111) at 433 K and 473 K sequentially. c, d Zoom-in STM and AFM images of two main products on Au(111) with CO tip. Setpoint: V = 300 mV, I = 30 pA; Δ z = 0.02 nm.