To analyze the influence of the substrate, Au(111) or Ag(111), on the length of the oligomers after annealing at 370 K, we have performed a statistical analysis over more than 370 oligomers (Figure ). From the histograms, it can be appreciated that the oligomers on Ag(111) are, on average, two times longer than on Au(111) for a similar coverage. This result can be attributed to several factors, such as the higher availability of surface adatoms on Ag(111) , which may promote the generation of longer chains; the presence of the herringbone reconstruction on the Au(111) surface, which could limit the oligomer length; and the surrounding iodine network around the oligomer islands on Au(111), which could hinder the molecular diffusion and the formation of longer oligomers.