Figure 6.

Measuring single-molecule motion on surfaces using STM. (a) Diffusion of aromatic acene on Cu{111} and Arrhenius plot of diffusion rate vsT. (b) STM images of single acene molecules bound to one and two CO₂ molecules, and Arrhenius plot showing reduced diffusion rate of acenes with CO₂ bound. (c) Automated analysis of diffusion of benzene on Au{111} based on image cross-correlation. Motion events are binned based on the number of nearest-neighbor benzenes to calculate association energies based on substrate-mediated interactions. Adapted from refs (104) and (109)−(111).