Regarding the apparently disordered area (green arrow), a non-homogeneous distribution of bright features (iodine atoms) can be observed. A separation between bright spots of around 2.6 nm (the double of the I-I distance in a I-BOPHY-I molecule) is observed, suggesting that they are the result of an intermolecular interaction between two partially dehalogenated molecules. Considering that a separation of ̴ 2.3 nm is expected for a covalent I-BOPHY-BOPHY-I structure, the value of ̴ 2.6 nm is attributed to a metal-organic dimer (I-BOPHY-M-BOPHY-I). To corroborate our assumption, we have simulated the STM images for metal-organic dimers, and an excellent agreement is achieved (see Figure ). These results are also in good accordance with our XPS results, as it will be shown below. Thus, these molecular structures would constitute the initial stages of the oligomer formation upon partial activation of the BOPHY molecules.