# When Aromaticity Falls Short in Molecule–Surface Interactions

## TL;DR

This paper shows that aromatic stabilization on surfaces is not always the main reason for molecular interactions, as hybridization and dative bonding can play a bigger role.

## Contribution

The study introduces a new mechanism where molecular π-systems form dative bonds with surfaces, challenging the traditional view of aromatic stabilization.

## Key findings

- Aromatic stabilization on surfaces can be outweighed by hybridization effects.
- Molecular π-systems can form dative bonds with surfaces, altering the expected aromatic interactions.
- Photoemission and theory reveal incomplete understanding of aromatic stabilization in surface interactions.

## Abstract

Aromaticity is one
of the most important concepts in
organic chemistry.
There are cases in which a molecule undergoes changes to increase
its aromaticity. This higher aromaticity comes with an energetic gain
and is commonly referred to as aromatic stabilization. Previously,
it has been reported that some molecules undergo such a stabilization
when adsorbing on a surface, which has been identified as the reason
for charge transfer into the molecular π-system. Utilizing photoemission
orbital tomography and density functional theory, we investigate changes
in the molecular π-system upon adsorption and elucidate the
influence on the aromaticity. We demonstrate how the energetic gain
from an aromatic stabilization on surfaces can be outweighed by hybridization.
Uncovering a mechanism in which the molecular π-system forms
dative bonds with the surface, our study reveals that the concept
of aromatic stabilization on surfaces has been incomplete so far.