Design und 2D Kristallisation von organischen Liganden und Metallkomplexen für die Entwicklung neuer funktioneller Oberflächen

Abstract

In this work molecules with catalytic and magnetic properties were used to structure and to functionalize surfaces. For this we used the simple but powerful technique of molecular self organisation which is employed since the beginning of organic life to produce highly complicated units. Even 2D crystals can be obtained applying this method. For this reason novel functional surfaces with catalytic and magnetic properties become accessable which are attactive materials for molecular electronics. Especially multi nuclear compounds are of great interest because of synergistic interactions between the metal centers. In the last years such complexes were in the focus of actual research due to their magnetic properties. The occurring spin coupling phenonema of the metal ions in multinuclear complexes are of great importance in the development of new information storage devices. In this work especially the design and the two dimensional self organisation of ligands and particularly metal complexes with interesting catalytic and magnetic properties were in the main focus of investigation. Highly ordered monolayers were created by exposing a drop of a solution of the designed functionalized organic and corresponding metal organic compounds in proper solvents like 1,2,4 trichlorobenzene or 1-octanol on the surface of a freshly cleaved highly oriented pyrolytic graphite (HOPG). The self organized arrangements of the molecules were visualised by scanning tunneling microscopy (STM) at the liquid/solid interface. The metal complexes were investigated in respect to their catalytic and magnetic properties. Furthermore in a synthetical approach derivatives of 2,4-dihydroxybenzaldehyde with polymerizable groups were prepared in order to stabilize the resulting physisorbed monolayers by intermolecular connection.