Fig. 4.

Direct imaging of reaction intermediates of TCMB coupling on Cu(111). a STM image of the intermediate I observed after TCMB deposited on Cu(111) at 4.7 K (I = 20 pA, V = –0.6 V). b, c STM images of intermediates II and III observed after elevated annealing process (I = 20 pA, V = –0.6 V). d–f The correponding nc-AFM images of a–c. g–i Simulated AFM images of the three typical reaction intermediates in d–f. j–l Top and side views of DFT-optimized models of the typical intermediates. Scale bars (a–i): 300 pm