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

TL;DR

This study demonstrates how scanning tunneling microscopy combined with theoretical calculations can induce and control molecule anchoring on a gold surface, enabling precise positioning for molecular device fabrication.

Contribution

It introduces a method for tip-induced chemical bonding of Ni-phthalocyanine molecules on Au(111), advancing molecular manipulation techniques.

Findings

Tip-induced current causes dehydrogenation of ligand in molecule.

Anchoring significantly reduces molecular diffusivity.

Method applicable to other molecules with similar ligands.

Abstract

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 Niphthalocyanine 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.