Surface-induced optimal packing of two-dimensional molecular networks.
Fiche publication
Date publication
février 2015
Journal
Physical review letters
Auteurs
Membres identifiés du Cancéropôle Est :
Dr CHERIOUX Frédéric
Tous les auteurs :
Copie G, Cleri F, Makoudi Y, Krzeminski C, Berthe M, Cherioux F, Palmino F, Grandidier B
Lien Pubmed
Résumé
High-density packing in organic crystals is usually associated with an increase of the coordination between molecules. Such a concept is not necessarily extended to two-dimensional molecular networks self-assembled on a solid surface, for which we demonstrate the key role of the surface in inducing the optimal packing. By a combination of scanning tunneling microscopy experiments and multiscale computer simulations, we study the phase transition between two polymorphs. We find that, contrary to intuition, the structure with the lowest packing fraction corresponds to the highest molecular coordination number, due to the competition between surface and intermolecular forces. Having the lowest free energy, this structure spreads out as the most stable polymorph over a wide range of molecular concentrations.
Référence
Phys Rev Lett. 2015 Feb 13;114(6):066101