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This article discusses different approaches to build up supramolecular nanoarchitectures on surfaces, which were simultaneously investigated by scanning tunneling microscopy (STM) on the single-molecule level. Following this general road map, first, the hydrogen-bonding guided self-assembly of two different, structural-equivalent molecular building blocks, azobenzene dicarboxylic acid and stilbene dicarboxylic acid, was studied. Secondly, the coordination chemistry of the same building blocks, now acting as ligands in metal coordination reactions, towards co-sublimed Fe atoms was studied under near surface-conditions. Extended two-dimensional tetragonal network formation with unusual Fe2L(4/2)-dimers at the crossing points was observed on copper surfaces. Complementary to the first two experiments, a two-step approach based on the solution-based self-assembly of square-like tetranuclear complexes of the M4L4-type with subsequent deposition on graphite surfaces was investigated. One- and two-dimensional arrangements as well as single molecules of the M4L4-complexes could be observed. Moreover, the local electronic properties of a single M4L4-complexes could be probed with submolecular resolution by means of scanning tunnelling spectroscopy (STS).

The adsorption of functional molecules on solid substrates is increasingly becoming an important aspect of nanoscience and sensing technology. Molecular and supramolecular electronics, understood as the integration of molecular structures to supplement specific functionalities on an integrated circuit chip, is a promising alternative approach for reducing both the feature size and the cost per functional unit. Driven by its characteristic control of the self-assembly process with nanometer accuracy, supramolecular chemistry has a deep impact on the realization of new concepts in molecular electronics. In particular, it plays a leading role in the future development of electronic devices at the solid-state/air interface; the intrinsic physical properties of supramolecular nanostructures can be screened in view of potential applications in nanotechnology. [1] Recent progress in supramolecular coordination chemistry allows access to a broad variety of transition-metal complexes of grid-type architecture comprising two-dimensional arrays of metal ions interconnected by a set of organic

Die kontrollierte Abscheidung von [2×2]‐CoII4‐Gitterkomplexen auf Graphitoberflächen ergab freistehende 0D‐, 1D‐ und 2D‐Molekülanordnungen, die mit Rastertunnelmikroskopie (STM) abgebildet wurden. Mit Rastertunnelspektroskopie (STS)‐Untersuchungen auf Einzelmolekülniveau wurden die Metallzentren innerhalb des Moleküls direkt adressiert (siehe Bild). Die so experimentell ermittelten Positionen der CoII‐Zentren innerhalb des Gittermoleküls stimmen mit den durch DFT‐Methoden errechneten überein.

I find in the square specific settings, divisible areas, number structures, possibilities of time, measure and rhythm as well as the essential form of color which can be placed in the square to interplay with number forms." Dieser Ausspruch von Alfred Jensen (zu sehen ist sein Gemälde "The River Diagram") kann auch für Arbeiten zu molekularen Quadraten gelten. So zeigen M. Ruben, J.-M. Lehn und P. Müller in der Zuschrift auf S. 8109 ff. die spektroskopische Zerlegung eines molekularen Quadrats in Regionen unterschiedlicher elektronischer Eigenschaften durch STM/STS.