DESIGN, SYNTHESIS AND ASSEMBLY OF NEW THIOPHENE-BASED MOLECULAR FUNCTIONAL UNITS WITH CONTROLLED PROPERTIES

Individual aspects in the field of 'molecular electronics' are addressed using new materials which are based on conjugated thiophenes as key building blocks. Among them, functionalized polythiophenes represent prototype compounds in which the three-dimensional network of 'molecular wires' can interact with the specific functional groups. Corresponding structurally defined oligothiophenes serve as model compounds and allow the correlation of various properties with structure. In addition, novel properties and superior processibility of these oligomers lead to interesting applications. Light emitting diodes and metal/organic/metal nanostructures are constructed by evaporation of thin oligomer films. A clear dependence of electroluminescence and electrical transport properties on chain length is found. Finally, the supramolecular assembly of functionalized (oligo)thiophenes is achieved by oriented adsorption on single crystal surfaces and self-organization in highly ordered LB films.