We report the presence of \sigma-aromaticity in a surface deposited cluster, Pd4 on TiO2 (110). In the gas phase, Pd4 adopts a tetrahedral structure. However, surface binding promotes a flat, \sigma-aromatic cluster. This is the first time aromaticity is found in surface deposited clusters. Systems of this type emerge as a promising class of catalyst, and so realization of aromaticity in them may help to rationalize their reactivity and catalytic properties, as a function of cluster size and composition.
@article{arxiv.1112.4032,
title = {Aromaticity in a Surface Deposited Cluster: Pd$_4$ on TiO$_2$ (110)},
author = {Jin Zhang and Anastassia N. Alexandrova},
journal= {arXiv preprint arXiv:1112.4032},
year = {2012}
}