Tuning intermolecular attraction to create polar order and one-dimensional nanostructures on surfaces.

This study utilizes atomic force microscopy and electrostatic force microscopy to investigate the orientation of overcrowded aromatics in films with submonolayer coverage. The results demonstrate that the side chains in the molecules can be used as a tool to control the molecular order and orientation in thin films. For molecules that do not self-associate well, the interaction with the substrate dominates, and the molecules orient with their aromatic planes parallel to the surface. These monolayers have measurable polar order. For molecules that self-associate well, the opposite orientation is observed. These films are comprised of isolated stacks of molecules parallel to the surface.