The experiments were carried out in three different UHV systems, with a base pressure of low 10 -10 mbar. Ag(111) and Au(111) single crystals (Mateck GmbH) were cleaned through repeated cycles of argon sputtering and annealing at 450°C before the evaporation of the molecules. The photoactive 2,7-diiodo-1,3,6,8-tetramethylbis(difluoroboron)-1,2-bis((1Hpyrrol-2-yl)methylene)hydrazine (from now on I-BOPHY-I) was synthesized in IMDEA-Energía following a previously described synthetic method and extra purified by sublimation . After that, molecules were thermally sublimed onto metallic support using a quartz crucible held at 175°C and evaporation rate of 1 Å/min, as determined by a quartz crystal microbalance (Inficon). The BOPHYbased metal-organic nanostructures were prepared by thermal activation onto Ag and Au(111) surfaces. Two different methods have been employed for the growth of the oligomers: i) precursor evaporation onto a hot surface and ii) precursor evaporation at room temperature (RT) and stepwise annealing. Similar results have been obtained in both cases. STM images were acquired in constant-current mode using a flow-cryostat low temperature scanning tunneling microscope LT-STM (STREAM SPM, Scienta Omicron) operated at 78K (LN2) or 8K (LHe) under UHV conditions. WSxM software was used as a tool for data analysis .