Supramolecular interaction of chiral molecules at the surface

Two-dimensional supramolecular chemistry on surfaces is strongly governed by directional non covalent forces. The chirality of the system plays an important role, especially in the two-dimensional case due to the confinement in the plane; a strong influence on the self-assembly pattern formation is provided by the absence of certain symmetry elements. For small flexible chiral organic molecules with two heteroatoms a very large self-assembly chiral domain governed by supramolecular interactions mediated by surface potential can be obtained on symmetric metallic surfaces. In the case of the adsorption of D-alaninol (2-amino-1-propanol) on Cu(100) surface, molecule-surface interaction may occur through both the amino and the hydroxyl groups or just involving one of them. Adsorbed alaninol molecules have been structurally and electronically characterized as a function of the surface molecular coverage by photoelectron spectroscopy (for core levels and valence region) and scanning tunneling microscopy (STM). The comparison of the experimental results with density functional theory calculations provides further insight into the D-alaninol/Cu(100) adsorption mechanism. © 2009 World Scientific Publishing Co. Pte. Ltd.