FN ISI Export Format VR 1.0 PT J TI Unveiling Adatoms in On-Surface Reactions AF Moreno-López, Juan Carlos Pérez Paz, Alejandro Gottardi, Stefano Solianyk, Leonid Li, Jun Monjas Gómez, Leticia Hirsch, Anna K. H. Mowbray, Duncan John Stöhr, Meike AU Moreno-López, JC Pérez Paz, A Gottardi, S Solianyk, L Li, J Monjas Gómez, L Hirsch, AKH Mowbray, DJ Stöhr, M SO The Journal of Physical Chemistry C VL 125 BP 9847 EP 9854 PY 2021 AB Scanning probe microscopy has become an essential tool to not only study pristine surfaces but also on-surface reactions and molecular self-assembly. Nonetheless, due to inherent limitations, some atoms or (parts of) molecules are either not imaged or cannot be unambiguously identified. Herein, we discuss the arrangement of two different nonplanar molecular assemblies of para-hexaphenyl-dicarbonitrile (Ph6(CN)2) on Au(111) based on a combined theoretical and experimental approach. For deposition of Ph6(CN)2 on Au(111) kept at room temperature, a rhombic nanoporous network stabilized by a combination of hydrogen bonding and antiparallel dipolar coupling is formed. Annealing at 575 K resulted in an irreversible thermal transformation into a hexagonal nanoporous network stabilized by native gold adatoms. However, the Au adatoms could neither be unequivocally identified by scanning tunneling microscopy nor by noncontact atomic force microscopy. By combining van’t Hoff plots derived from our scanning probe images with our density functional theory calculations, we were able to confirm the presence of the elusive Au adatoms in the hexagonal molecular network. ER