Author:

Abstract:

Controlling the adsorption and structural transition of organic molecule s on solid surfaces is of fundamental and technological significance. Po lycyclic aromatic compounds in particular are promising as active materi als in supramolecular electronic and optoelectronic devices, because the electronic properties of their flat conjugated systems can be varied dr amatically through synthetic modification of their size and topologies. In this thesis, we focus on the self-assembly behavior of two kinds of p olyaromatic compounds on Au(111), studied by scanning tunneling microsco py (STM) and electrochemical scanning tunneling microscopy (EC-STM). The first kind is the shape-persistent hexagonal macrocycle heterotriangule ne, which we investigate as a template to trap three different kinds of guest molecules at different sites of its nanoporous network. The second class of compounds are PQPs, organic salts that consist of a disc-shape d polyaromatic cation and a variety of anions. Under electroc hemical conditions, we demonstrate excellent potential control over the self-assembly behavior, yielding patterns of increasing packing density containing from 2 up to 7 tectons per supramolecular motif, dynamic pore s, or a transition between 2- and 3-dimensional self-assembly. We believ e that our results bring us a step closer to high-tech practical applica tions such as artificial receptors and smart materials.