Porphyrin- und Porphyrin-Fulleren-Derivate - Synthese und Immobilisierung auf Goldoberflächen

Abstract

Primary object of this work was the derivatisation of porphyrins and fullerenes for enabling them to adsorb and co-adsorb on gold surfaces, respectively. The adsorbates were designed according to a tool box concept. Starting from the red blood pigment heme, partial synthetic routes easily lead to desired products. Commercially available hemin was first converted to deuteroporphyrin dimethylester, which served as starting material. Metalloporphyrins and fullerenes were both functionalised by bis-lipoic acid anchors. A fullerene SAM could be postmodified by Diels-Alder reaction without cleaving the gold-sulphur bond yielding a Zn(II) porphyrin fullerene dyad. Due to strong surface attachment it should be possible to generate a photocurrent using said donor-acceptor pair. Immobilised species were electrochemically and morphologically characterised by state-of-the-art techniques. Surface coverages of modified gold electrodes were calculated after reductive desorption in strong alkaline solution. Nanostructured surfaces exposing different chemical functionalities were tested regarding sensor and catalytic activities.