Tip-Induced Molecule Anchoring in Ni-Phthalocyanine on Au(111) Substrate

Pinning single molecules at desired positions can provide opportunities to fabricate bottom-up designed molecular machines. Using the combined approach of scanning tunneling microscopy and density functional theory, we report on tip-induced anchoring of Ni-phthalocyanine molecules on an Au(111) substrate. We demonstrate that the tip-induced current leads to the dehydrogenation of a benzene-like ligand in the molecule, which subsequently creates chemical bonds between the molecule and the substrate. It is also found that the diffusivity of Ni-phthalocyanine molecules is dramatically reduced when the molecules are anchored on the Au adatoms produced by bias pulsing. The tip-induced molecular anchoring would be readily applicable to other functional molecules that contain similar ligands.