SUPPORTING INFORMATION
Room temperature metalation of 2H-TPP monolayer on Fe and Ni surfaces by picking-up substrate metal atoms 1,*
2
Andrea Goldoni , Carlo A. Pignedoli , Giovanni Di Santo1, Carla Castellarin-Cudia1, Elena Magnano3, Federica Bondino3, Alberto Verdini3, Daniele Passerone2 1
ST-INSTM laboratory, Sincrotrone Trieste S.C.p.A., s.s. 14 km 163.5 in Area Science Park, 34149 Trieste, Italy
2
Empa Swiss Federal Laboratiories for Materials Science and Technology, Nanotech@surfaces laboratory, Ueberlandstrasse
129, 8600 DüBendorf, Switzerland 3
TASC laboratory, CNR-IOM, s.s. 14 km 163.5 in Area Science Park, 34149 Trieste, Italy
In this paragraph we provide new information on the ultra-high-vacuum metalation of 2H-TPP on Ag(111) by evaporation of Rh and Mn atoms and then we discuss another molecular configuration on Ni(111) that apparently may be more stable than the one calculated in the manuscript, but presents discrepancy with our and other experiments. Figure S1 and S2 show the evolution of the N 1s core level photoemission spectrum of one monolayer of 2H-TPP on Ag(111) as Rh and Mn atoms, respectively, were evaporated on the substrate surface until an almost complete metalation is obtained. The spectra were taken in several experiments using different photon energies. Anyway it is clear the tendency of the N 1s peaks to reduce to just one peak, indicating the metalation of the macrocycle. For the Rh metalation the spectra were annealed to 570 K after Rh deposition in the multilayer, while in the case of Mn the metalation takes place at room temperature.
Fig. S1: Evolution of the N 1s core level spectra for monolayer (top) and multilayer (bottom) of 2H-TPP/Ag(111) during Rh evaporation. The red spectra are the pristine 2H-TPP while the black spectra are the almost completely metalated Rh-TPP
Fig. S2: Evolution of the N 1s core level spectra for a monolayer of 2H-TPP/Ag(111) during Mn evaporation. The red spectrum is the pristine 2H-TPP while the black spectrum is the almost completely metalated Mn-TPP
Now we discuss a new set of possible calculated configurations starting from a geometry were iminic N atoms point towards the surface, that is the opposite of the configuration obtained in the manuscript. We were able to find a new state, considerably more stable (5.8 eV) compared to the geometries already discussed. Remarkably, in this state the phenyl rings are flat as well as the distorted pyrrolic groups, whereas two strong chemical bonds are formed between the upright iminic groups and a Ni surface atom, without any metalation of the molecule. However, the geometry that we find is not compatible with the experimental findings, neither something of this kind, with flat phenyl rings and upright iminic groups has been ever observed experimentally.
Fig. S3: Calculated stable configuration of 2H-TPP/Ni(111) obtained starting with the iminic N atoms pointing toward the substrate.
So the question is what is hindering reaching such an extreme state as the one depicted in the figure in the case of Ni(111) adsorption. Since our XPS data indicate a single N peak, we can speculate that the metalation of the molecule occurs before the transformation of the “rotated phenyls and flat macrocycle” state to the “upright iminic/flat pyrrolic and flat phenyls” state. Once the Ni atom is incorporated, the four nitrogen atoms are bound to the central Ni atom as shown in the manuscript, and leaving that state would require the breaking of chemical bonds - with subsequent very high energetic barriers. Further investigation is required, both on the theoretical side (to isolate the kinetic bottlenecks hindering reaching our most stable state) and on the experimental side (to create appropriate conditions for reaching this state without metalation).
