Chemical versus van der Waals Interaction: The Role of the Heteroatom

TL;DR

This study uses first-principles calculations to explore how heteroatoms like nitrogen influence chemical and van der Waals interactions during the adsorption of pi-conjugated molecules on Cu(110), revealing orbital-dependent effects.

Contribution

It demonstrates the impact of heteroatoms on the alignment of molecular orbitals and the nature of vdW interactions in molecule-surface adsorption.

Findings

Heteroatoms affect molecular orbital alignment at the interface.

vdW interactions involve both pi-like and sigma-like orbitals.

Orbital delocalization influences adsorption characteristics.

Abstract

We performed first-principles calculations aimed to investigate the role of an heteroatom like N in the chemical and the long-range van der Waals (vdW) interactions for a flat adsorption of several pi-conjugated molecules on the Cu(110) surface. Our study reveals that the alignment of the molecular orbitals at adsorbate-substrate interface depends on the number of heteroatoms. As a direct consequence, the molecule-surface vdW interactions involve not only pi-like orbitals which are perpendicular to the molecular plane but also sigma-like orbitals delocalized in the molecular plane.